I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If thelayout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.
I don't get why mil are still used in PCB layout so much.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
fredag den 18. februar 2022 kl. 15.45.50 UTC+1 skrev gnuarm.del...@gmail.com:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell >> right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If the
https://erp.eso-electronic.com/files/Oi90JOl.png
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. Ifthe layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.
I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that cantrigger the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or
On 02/18/2022 03:45 PM, Rick C wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell >>>> right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If the
the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or something. I don'I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that can trigger
Because it's 1 to two digit small integers for all the practical
sizes on a board.
The millimeter/micrometer sizes are all off by at least a factor of ten
to be convenient.
metric pin headers/screw clamps are also sh!t
it works to have 2 pins 5.00mm in 5.08(2x100mil) holes.
but when it's 8 pins long or so it won't fit anymore.
(perfboards!)
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
If I'd printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn't.
Sylvia.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen Belleman
On Fri, 18 Feb 2022 19:31:48 +1100, Sylvia Else <syl...@email.invalid>
wrote:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial andYour PCB layout program library (or person) must be ambiguous.
metric sizes? No wonder there's no way I can put my imperial 0603 >components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
If I'd printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn't.
Sylvia.Since SMT originated in the USA, at IBM, everyone could have kept the original size nomenclature. Or at least done something original if
they insisted on going metric, like 06M03 or something. An M8 screw is clearly distinct from a number 8.
On Fri, 18 Feb 2022 12:01:14 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen Belleman
The early IC designers defined as inch as equal to 25 mm.
I like to use 0805s. 0603s are getting too small to handle and probe.
I recently used some 0402s for some really fast stuff, and I hate
them. Metric 0602 is 0201 in plain English, spec-of-dust size.
On Fri, 18 Feb 2022 12:01:14 +0100, Jeroen Belleman
<jer...@nospam.please> wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen BellemanThe early IC designers defined as inch as equal to 25 mm.
On Friday, February 18, 2022 at 10:26:18 AM UTC-5, Johann Klammer wrote:still did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 02/18/2022 03:45 PM, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and >>>> metric sizes? No wonder there's no way I can put my imperial 0603 >>>> components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell >>>> right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they
the layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If
trigger the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches orI don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that can
by the application) by 110 mm (selected by me).Because it's 1 to two digit small integers for all the practicalSorry, what is convenient about 250 mil? Or 850 mil, or 4500 mil? I'm good with 6.35 mm or better just 6 mm for a mounting pad. My board is 21.6 x 114 mm in metric. I don't find that cumbersome although I probably would have made it 21.6 mm (required
sizes on a board.
The millimeter/micrometer sizes are all off by at least a factor of ten
to be convenient.
and 1 mm, but 2.5 mm??? What are these 5.0 mm connectors, more than 8 pins long? I'm guessing something that might be used in a washing machine sort of appliance?metric pin headers/screw clamps are also sh!tI haven't used a perf board in 20 years. I also don't typically use through hole, although it does show up for cable connectors for ribbon cables. In that case, 2.5 mm spaced connectors are not an option. I didn't know they made them. I've seen 2 mm
it works to have 2 pins 5.00mm in 5.08(2x100mil) holes.
but when it's 8 pins long or so it won't fit anymore.
(perfboards!)
On 2022-02-18 17:06, jla...@highlandsniptechnology.com wrote:
On Fri, 18 Feb 2022 12:01:14 +0100, Jeroen Belleman
<jer...@nospam.please> wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen Belleman
The early IC designers defined as inch as equal to 25 mm.The point is not whether we should use metric or inches. The
point is that the /syntax/ of the size designators should be
distinguishable. Without further indications, I would assume
that 0603 is imperial.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
Designed to confuse. Why do people do that?
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
On 18/02/2022 14:45, Rick C wrote:
<snipped>
I don't get why mil are still used in PCB layout so much.
For a thousandth of an inch, we say 'thou' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or
millilitre, depending on context.
That has caused much confusion too.
On Friday, February 18, 2022 at 6:45:50 AM UTC-8, gnuarm.del...@gmail.com wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
Pre-NATO, all US military machinery would have been inches; even now,
NATO has standard 7.62 mm ammo, which is just a soft-conversion
from .30 caliber...
Conversion is a slow process. In the print industries, inches have been the norm; in
science, it has been SI (metric) units for decades. So early semiconductor designs
had diffusion depths in microns, and emitter areas in... square micro-inches.
Because the emitters were printed.
Eventually it gets sorted out... but I've got a century-old machine tool that has inch-standard parts everywhere except one lefthand metric screw... so don't expect the conversion-in-progress phase to be complete in your lifetime. Digitization, if anything, will impede the progress; your calipers are made with a 'convert to' button, so the multiple standards don't
bother one so much.
On Fri, 18 Feb 2022 12:01:14 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen Belleman
The early IC designers defined as inch as equal to 25 mm.
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur
<cl...@nowaytoday.co.uk> wrote:
On 18/02/2022 14:45, Rick C wrote:
<snipped>
I don't get why mil are still used in PCB layout so much.
For a thousandth of an inch, we say 'thou' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or >millilitre, depending on context.
That has caused much confusion too.Not so fast there. Too Euro-centric?
In the US, traditionally a "mil" is 0.001", and a "tenth" is 0.0001",
and a millimeter is a millimeter ("mm") and never a mil.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
Designed to confuse. Why do people do that?
Jeroen Belleman
On Friday, February 18, 2022 at 6:45:50 AM UTC-8, gnuarm.del...@gmail.com wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
Pre-NATO, all US military machinery would have been inches; even now,
NATO has standard 7.62 mm ammo, which is just a soft-conversion
from .30 caliber...
Conversion is a slow process. In the print industries, inches have been the norm; in
science, it has been SI (metric) units for decades. So early semiconductor designs
had diffusion depths in microns, and emitter areas in... square micro-inches.
Because the emitters were printed.
Eventually it gets sorted out... but I've got a century-old machine tool that has inch-standard parts everywhere except one lefthand metric screw... so don't expect the conversion-in-progress phase to be complete in your lifetime. Digitization, if anything, will impede the progress; your calipers are made with a 'convert to' button, so the multiple standards don't
bother one so much.
fredag den 18. februar 2022 kl. 19.51.04 UTC+1 skrev whit3rd:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,wrote:
gnuarm.del...@gmail.com
:On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen
Belleman wrote
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia
Else:
I've got a board made that includes pads for some 0603
smds.
How was I expected to know that 0603 is used for both
imperial and
metric sizes? No wonder there's no way I can put my
imperial 0603
heir country use? I guess this is a more pointed question at theDesigned to confuse. Why do people do that?components onto the metric 0603 landing pads.
You mean why do people use the measuring system that everyone
else in t
US community. I remember working with a mechanical engineer at a
military contractor and was surprised they still did everything
using inches. 90% of electronic components are in mm as the
primary unit. I guess I expect the mechanical community would have
converted by now, but, no.
Pre-NATO, all US military machinery would have been inches; evenhe norm; in
now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
Conversion is a slow process. In the print industries, inches
have been t
science, it has been SI (metric) units for decades. So earlyr designs
semiconducto
had diffusion depths in microns, and emitter areas in... squarehes.
micro-inc
Because the emitters were printed.
Eventually it gets sorted out... but I've got a century-old
machine tool
that has inch-standard parts everywhere except one lefthand..
metric screw.
so don't expect the conversion-in-progress phase to be complete
in your
lifetime. Digitization, if anything, will impede the progress;ers
your calip
are made with a 'convert to' button, so the multiple standards
don't bother one so much.
or it might help, if all your tools/machines/instruments can only
do one standard switching means throwing it all away. If they can
do both like every CNC or digital caliper switching is just a push
of a button
On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur0.0001",
<clive@nowaytoday.co.uk> wrote:
On 18/02/2022 14:45, Rick C wrote:
<snipped>
I don't get why mil are still used in PCB layout so much.
For a thousandth of an inch, we say 'thou' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or >>millilitre, depending on context.
That has caused much confusion too.
Not so fast there. Too Euro-centric?
In the US, traditionally a "mil" is 0.001", and a "tenth" is
and a millimeter is a millimeter ("mm") and never a mil.
Joe Gwinn
On 18/02/2022 14:45, Rick C wrote:
<snipped>
I don't get why mil are still used in PCB layout so much.
For a thousandth of an inch, we say 'thou' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or
millilitre, depending on context.
That has caused much confusion too.
The early IC designers defined as inch as equal to 25 mm.
On Fri, 18 Feb 2022 15:02:21 +0000, Clive Arthur
<cl...@nowaytoday.co.uk> wrote:
On 18/02/2022 14:45, Rick C wrote:
<snipped>
I don't get why mil are still used in PCB layout so much.
For a thousandth of an inch, we say 'thou' (with the th as in
thousandth). A mil is often verbal shorthand for a millimetre or >millilitre, depending on context.
That has caused much confusion too.In the US, machinists usually say thou and engineers most often say
mils, both meaning 0.001 inches.
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
The Gimli Glider was about confusing gallons with liters.
On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:
<snip>
The early IC designers defined as inch as equal to 25 mm.
Many decades ago I bought some stripboard for a prototype. It was 2.5mm >pitch, which I assumed was really meant to be 0.1".
It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor
were well bent, like a man trying to fit into too small shoes.
I do have a lot of sympathy for some 'imperial' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that's because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.
We need to make 16 the default number base. You know it makes sense.
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:still did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:45:50 AM UTC-8, gnuarm.del...@gmail.com wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and >> metric sizes? No wonder there's no way I can put my imperial 0603 >> components onto the metric 0603 landing pads.
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they
Pre-NATO, all US military machinery would have been inches; even now,
NATO has standard 7.62 mm ammo, which is just a soft-conversion
from .30 caliber...
Designed to confuse. Why do people do that?
It's a damn good thing they had already developed metric measurements for electricity by the time things got rolling.
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:
On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:
<snip>
The early IC designers defined as inch as equal to 25 mm.
Many decades ago I bought some stripboard for a prototype. It was 2.5mm >>pitch, which I assumed was really meant to be 0.1".
It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor >>were well bent, like a man trying to fit into too small shoes.
I do have a lot of sympathy for some 'imperial' units. For example, I
have a set of scales in the kitchen with both metric and imperial
weights. The imperial weights have no duplicates. The metric weights
have two of 200g and two of 20g. Yes, I realise that's because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.
We need to make 16 the default number base. You know it makes sense.
Hard to count on the fingers?
I knew a woman who had six fingers on each hand, all fingers looking
and working normally. But she didn't even attempt to get to eight
fingers per hand.
Joe Gwinn
On Fri, 18 Feb 2022 18:38:32 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:
On 18/02/2022 16:06, jlarkin@highlandsniptechnology.com wrote:
<snip>
The early IC designers defined as inch as equal to 25 mm.
Many decades ago I bought some stripboard for a prototype. It was 2.5mm >>>pitch, which I assumed was really meant to be 0.1".
It was in fact 2.5mm as claimed, and the pins on my 40 pin DIL processor >>>were well bent, like a man trying to fit into too small shoes.
I do have a lot of sympathy for some 'imperial' units. For example, I >>>have a set of scales in the kitchen with both metric and imperial >>>weights. The imperial weights have no duplicates. The metric weights >>>have two of 200g and two of 20g. Yes, I realise that's because there
are 2^4 ounces in a pound. Likewise, inches in halves, quarters,
eights, sixteenths etc - very convenient and easy to eyeball.
We need to make 16 the default number base. You know it makes sense.
Hard to count on the fingers?
Hard for kids to learn the addition and multiplication tables.
Most DEC computers were octal, even the 16-bit PDP-11. I can still
assemble some octal instructions from memory.
012737 Move word immediate to absolute location
nnnnn
aaaaa
I knew a woman who had six fingers on each hand, all fingers looking
and working normally. But she didn't even attempt to get to eight
fingers per hand.
Joe Gwinn
Base 12 has been proposed to replace 10.
There must be some FOR loop in our DNA that wraps around a subroutine
called FINGER. Maybe one base pair is the index.
What's amazing is that the 6th finger actually works, has veins and
nerves and muscles and tendons and stuff.
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
If I'd printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn't.
Sylvia.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
If I'd printed out the PCB layout at 1:1 scale, I might have realised
that the pads were absurdly small, but of course, I didn't.
Sylvia.
On 19-Feb-22 1:45 am, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use?
No, I think the question was why was a size code needlessly duplicated?
The numbers are only an approximation to the size anyway. Whichever came >second could have been named 0604, without any other impact whatsoever.
Sylvia.
On 19-Feb-22 1:45 am, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell >>>> right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use?No, I think the question was why was a size code needlessly duplicated?
The numbers are only an approximation to the size anyway. Whichever came second could have been named 0604, without any other impact whatsoever.
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
Then there are the sideways caps, like 0306.
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches; even
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was surprised
they still did everything using inches. 90% of electronic
components are in mm as the primary unit. I guess I expect the
mechanical community would have converted by now, but, no.
now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing nomenclature
and changing measurement systems. Caliber is not an actual
measurement of anything, rather a nominal use. Same as 12 inch
wafers or a 19 inch rack cabinet. I guess something on a 19 inch
rack cabinet is actually 19 inches, but in reality, it's just a name
we use.
On Fri, 18 Feb 2022 18:38:32 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:
We need to make 16 the default number base. You know it makes sense.
Hard to count on the fingers?
Base 12 has been proposed to replace 10.
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches; even
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was surprised
they still did everything using inches. 90% of electronic
components are in mm as the primary unit. I guess I expect the
mechanical community would have converted by now, but, no.
now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing nomenclature
and changing measurement systems. Caliber is not an actual
measurement of anything, rather a nominal use. Same as 12 inch
wafers or a 19 inch rack cabinet. I guess something on a 19 inch
rack cabinet is actually 19 inches, but in reality, it's just a name
we use.
I think a key point on units is whether you need to convert them or not,
and how they are compared to different measurements. If you need to
convert things into real lengths, weights, or whatever, then metric is
the only sane choice. But often you don't need conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or long,
0.44 kg in weight, or whatever - it's just a name, and as long as you
match up the name used on the gun and the ammo, you're fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size. You don't measure the height
of the rack in centimetres - you measure it in "units" because
everything that goes in the rack is an integer number of "units" in
height. If you want to know if your new 4 unit server will fit in your
rack, you count the number of units of space you have left - conversion
to millimetres or measuring with an inchtape would be silly.
On the other side, the size of your pcb tracks and footprints, or screw threads, or mechanical drawings, all need to be as accurate as
practically possible, and all need to be specified in a precise scale - metric.
On Saturday, February 19, 2022 at 6:17:25 AM UTC-5, David Brown
wrote:
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:I think a key point on units is whether you need to convert them or
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches;
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was
surprised they still did everything using inches. 90% of
electronic components are in mm as the primary unit. I guess
I expect the mechanical community would have converted by
now, but, no.
even now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing
nomenclature and changing measurement systems. Caliber is not an
actual measurement of anything, rather a nominal use. Same as 12
inch wafers or a 19 inch rack cabinet. I guess something on a 19
inch rack cabinet is actually 19 inches, but in reality, it's
just a name we use.
not, and how they are compared to different measurements. If you
need to convert things into real lengths, weights, or whatever,
then metric is the only sane choice. But often you don't need
conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or
long, 0.44 kg in weight, or whatever - it's just a name, and as
long as you match up the name used on the gun and the ammo, you're
fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size. You don't measure the
height of the rack in centimetres - you measure it in "units"
because everything that goes in the rack is an integer number of
"units" in height. If you want to know if your new 4 unit server
will fit in your rack, you count the number of units of space you
have left - conversion to millimetres or measuring with an inchtape
would be silly.
On the other side, the size of your pcb tracks and footprints, or
screw threads, or mechanical drawings, all need to be as accurate
as practically possible, and all need to be specified in a precise
scale - metric.
That is an error. There is nothing more precise about metric than
imperial units.
It's just a matter of convenience. For some metric
is more convenient because it's what they are used to, but also the advantages of a decimal based system with few conversion factors.
For others imperial is what they are used to and need to learn the
conversion factors... many conversion factors... many, many
conversion factors. But both are equally precise.
On 19/02/2022 15:15, Rick C wrote:
On Saturday, February 19, 2022 at 6:17:25 AM UTC-5, David Brown
wrote:
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:I think a key point on units is whether you need to convert them or
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches;
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was
surprised they still did everything using inches. 90% of
electronic components are in mm as the primary unit. I guess
I expect the mechanical community would have converted by
now, but, no.
even now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing
nomenclature and changing measurement systems. Caliber is not an
actual measurement of anything, rather a nominal use. Same as 12
inch wafers or a 19 inch rack cabinet. I guess something on a 19
inch rack cabinet is actually 19 inches, but in reality, it's
just a name we use.
not, and how they are compared to different measurements. If you
need to convert things into real lengths, weights, or whatever,
then metric is the only sane choice. But often you don't need
conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or
long, 0.44 kg in weight, or whatever - it's just a name, and as
long as you match up the name used on the gun and the ammo, you're
fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size. You don't measure the
height of the rack in centimetres - you measure it in "units"
because everything that goes in the rack is an integer number of
"units" in height. If you want to know if your new 4 unit server
will fit in your rack, you count the number of units of space you
have left - conversion to millimetres or measuring with an inchtape
would be silly.
On the other side, the size of your pcb tracks and footprints, or
screw threads, or mechanical drawings, all need to be as accurate
as practically possible, and all need to be specified in a precise
scale - metric.
That is an error. There is nothing more precise about metric thanI know that, and it is not actually what I said.
imperial units.
If everyone used imperial units consistently (which could work for
lengths, though some imperial units are different in different
countries), they could be precise.
But they don't - and conversions back and forth will mean inaccuracies
creep in and rounding errors can add up.
When accuracy is important, the world uses metric - except for a
decreasing proportion of hold-outs in the USA. If your drawings,
designs or measurements pass through the hands of imperial unit users in
the USA, accuracy is likely to drop.
It is not just important that you use a precise scale - some imperial
scales are as precise as metric. (An inch is formally defined as 25.4
mm.) But you need to use a /single/ scale - the same scale everyone
else uses. Metric.
jlarkin@highlandsniptechnology.com wrote:
Then there are the sideways caps, like 0306.
And resistors. I like the 0612 for current sensing.
Best regards, Piotr
On 19/02/2022 01:34, John Larkin wrote:
On Fri, 18 Feb 2022 18:38:32 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
On Fri, 18 Feb 2022 23:13:26 +0000, Clive Arthur
<clive@nowaytoday.co.uk> wrote:
We need to make 16 the default number base. You know it makes sense.
Hard to count on the fingers?
Some cultures use additional parts of their hand (or even the rest of
their body) in counting.
Base 12 has been proposed to replace 10.Base 12 has been used for many things - that's why we have "a dozen" and
"a gross". Base 20 has also been popular (hence "a score"). And mixes
of bases have been used historically - the Sumerians and Babylonians alternated between 12 and 5, giving 60 per digit pair, from whence 60
seconds in a minute, 60 degrees in a triangle.
But for larger numbers, a consistent base is a lot easier. Either 12 or
16 might have been a better choice than 10, but it's hard to change now!
I'd prefer base 16 - it makes calculating the digits of π easier :-)
John Larkin <jlarkin@highland_atwork_technology.com> wrote:
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement devices
a huge list to calculate the units for US customers. When you read this
it is very strange that they claim to reach the moon. :-D
Oh..and it is one of the reason why american cars are not so popular
in Germany. People wonder how to repair them with strange threads
and unusual tools.
Whenever I read about AWG, 0.5oz copper or number drill sizes I have
to shake my head.
Olaf
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches; even
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was surprised
they still did everything using inches. 90% of electronic
components are in mm as the primary unit. I guess I expect the
mechanical community would have converted by now, but, no.
now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing nomenclature
and changing measurement systems. Caliber is not an actual
measurement of anything, rather a nominal use. Same as 12 inch
wafers or a 19 inch rack cabinet. I guess something on a 19 inch
rack cabinet is actually 19 inches, but in reality, it's just a name
we use.
I think a key point on units is whether you need to convert them or not,
and how they are compared to different measurements. If you need to
convert things into real lengths, weights, or whatever, then metric is
the only sane choice. But often you don't need conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or long,
0.44 kg in weight, or whatever - it's just a name, and as long as you
match up the name used on the gun and the ammo, you're fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size.
You don't measure the height
of the rack in centimetres - you measure it in "units" because
everything that goes in the rack is an integer number of "units" in
height. If you want to know if your new 4 unit server will fit in your
rack, you count the number of units of space you have left - conversion
to millimetres or measuring with an inchtape would be silly.
On the other side, the size of your pcb tracks and footprints, or screw >threads, or mechanical drawings, all need to be as accurate as
practically possible, and all need to be specified in a precise scale - >metric.
measure inches as accurately as you can measure centimeters.
Does anybody use centimeters? Seems like an orphan unit.
[...]
On 19/02/2022 15:15, Rick C wrote:
On Saturday, February 19, 2022 at 6:17:25 AM UTC-5, David Brown
wrote:
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd wrote:I think a key point on units is whether you need to convert them or
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches;
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was
surprised they still did everything using inches. 90% of
electronic components are in mm as the primary unit. I guess
I expect the mechanical community would have converted by
now, but, no.
even now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing
nomenclature and changing measurement systems. Caliber is not an
actual measurement of anything, rather a nominal use. Same as 12
inch wafers or a 19 inch rack cabinet. I guess something on a 19
inch rack cabinet is actually 19 inches, but in reality, it's
just a name we use.
not, and how they are compared to different measurements. If you
need to convert things into real lengths, weights, or whatever,
then metric is the only sane choice. But often you don't need
conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or
long, 0.44 kg in weight, or whatever - it's just a name, and as
long as you match up the name used on the gun and the ammo, you're
fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size. You don't measure the
height of the rack in centimetres - you measure it in "units"
because everything that goes in the rack is an integer number of
"units" in height. If you want to know if your new 4 unit server
will fit in your rack, you count the number of units of space you
have left - conversion to millimetres or measuring with an inchtape
would be silly.
On the other side, the size of your pcb tracks and footprints, or
screw threads, or mechanical drawings, all need to be as accurate
as practically possible, and all need to be specified in a precise
scale - metric.
That is an error. There is nothing more precise about metric than
imperial units.
I know that, and it is not actually what I said.
If everyone used imperial units consistently (which could work for
lengths, though some imperial units are different in different
countries), they could be precise.
But they don't - and conversions back and forth will mean inaccuracies
creep in and rounding errors can add up.
When accuracy is important, the world uses metric - except for a
decreasing proportion of hold-outs in the USA. If your drawings,
designs or measurements pass through the hands of imperial unit users in
the USA, accuracy is likely to drop.
Does anybody use centimeters? Seems like an orphan unit.
jla...@highlandsniptechnology.com wrote:
#10 wire is 0.1" diameter and 1 milliohm per foot. #20 is 10Only if you have a feeling what a "foot" is. :-)
mohms/foot. #30, 100 mohms. Easy to remember.
#10 wire is 0.1" diameter and 1 milliohm per foot. #20 is 10
mohms/foot. #30, 100 mohms. Easy to remember.
On 19/02/2022 15:15, Rick C wrote:
There is nothing more precise about metric thanI know that, and it is not actually what I said.
imperial units.
If everyone used imperial units consistently (which could work for
lengths, though some imperial units are different in different
countries), they could be precise.
But they don't - and conversions back and forth will mean inaccuracies
creep in and rounding errors can add up.
When accuracy is important, the world uses metric - except for a
decreasing proportion of hold-outs in the USA. If your drawings,
designs or measurements pass through the hands of imperial unit users in
the USA, accuracy is likely to drop.
On Saturday, February 19, 2022 at 6:27:22 AM UTC-8, David Brown wrote:
On 19/02/2022 15:15, Rick C wrote:
There is nothing more precise about metric thanI know that, and it is not actually what I said.
imperial units.
If everyone used imperial units consistently (which could work for
lengths, though some imperial units are different in different
countries), they could be precise.
But they don't - and conversions back and forth will mean inaccuracies
creep in and rounding errors can add up.
Oh, that's a solved problem, though; sometime in the past (1935?) the US
made a three-digit conversion from 'inch' to 'meter' that is definitive (it defines the inch in SI units, so Systeme Internationale applies). We here in US have to deal with 'statute mile' versus 'mile' as a result, but...that's
not an international problem).
Conversions can be exact, but of course there's no getting around numeric-representation errors; diagonal of a square isn't rational, so
we NEVER have "all" of the digits written down. That's not a standards problem, it's just... a problem.
The 'inch' was never international-standard; Denmark had a different inch. That's why it makes little sense to make a local inch the definition of
a meter. France did the world a favor when (after a king redefined the 'bushel' measure to increase land rents) declared a new measure for
world distribution.
When accuracy is important, the world uses metric - except for a
decreasing proportion of hold-outs in the USA. If your drawings,
designs or measurements pass through the hands of imperial unit users in
the USA, accuracy is likely to drop.
Not just the USA; all NATO countries accept #6-32 screws as 'a' standard size, and
BSP (British Standard Pipe) pipe threads are all over the world. Accuracy is
available equally to all, and calculators can handle more digits than I've ever needed.
Cube roots to ten digits was painful before personal computing, but I could do it
with the right glowing-digits office machine. Slide rule, though, wasn't gonna work.
available equally to all, and calculators can handle more digits than I've ever needed.
On 2/19/2022 12:48 PM, whit3rd wrote:
...sometime in the past (1935?) the US
made a three-digit conversion from 'inch' to 'meter' that is definitive (it defines the inch in SI units, so Systeme Internationale applies). We here in US have to deal with 'statute mile' versus 'mile' as a result, but...that's
not an international problem).
Which 'mile' do you mean? 'Nautical mile' perhaps?
jlarkin@highlandsniptechnology.com wrote:
#10 wire is 0.1" diameter and 1 milliohm per foot. #20 is 10
mohms/foot. #30, 100 mohms. Easy to remember.
Only if you have a feeling what a "foot" is. :-)
Olaf
On 2022-02-19 17:45, jlarkin@highlandsniptechnology.com wrote:
[...]
measure inches as accurately as you can measure centimeters.
Does anybody use centimeters? Seems like an orphan unit.
[...]
We don't think of centimeters as a unit. The unit is the
meter. Centi is just a prefix meaning 1/100th. Engineers
tend to use mostly prefixes that are powers of 1000.
There are some weird exceptions. You'll see hPa because it
happens to be close to 1mbar. You'll see daN because it
happens to be near the downward force of a 1kg mass.
Jeroen Belleman
It is not just important that you use a precise scale - some imperial
scales are as precise as metric. (An inch is formally defined as 25.4
mm.)
On Sat, 19 Feb 2022 18:07:48 +0100, Jeroen Belleman
<jer...@nospam.please> wrote:
On 2022-02-19 17:45, jla...@highlandsniptechnology.com wrote:
[...]
measure inches as accurately as you can measure centimeters.
Does anybody use centimeters? Seems like an orphan unit.
[...]
We don't think of centimeters as a unit. The unit is the
meter. Centi is just a prefix meaning 1/100th. Engineers
tend to use mostly prefixes that are powers of 1000.
There are some weird exceptions. You'll see hPa because it
happens to be close to 1mbar. You'll see daN because it
happens to be near the downward force of a 1kg mass.
Jeroen BellemanThe metric scales on most rulers here are in cm. I always convert to
mm.
What do you use for tire pressure? We use PSI, ballpark 30.
The old english units are physically handy. Most common things work
out to be 1 or 2-digit integers, probably because worker-guys have
used them for centuries.
I ordered some cognac in Paris and the bartender asked me how many milliliters I wanted. I had no clue so I said "medium" and he grunted
and poured.
In the US, whiskey is measured in "jiggers." A sensible bartender
holds the jigger over the glass, pours until it's full, lets it
overflow for a while, then dumps it in. Good for tips.
John Larkin <jlarkin@highland_atwork_technology.com> wrote:
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When you
read this it is very strange that they claim to reach the moon. :-D
olaf wrote:
John Larkin <jlarkin@highland_atwork_technology.com> wrote:
Surprisingly, some big aerospace companies still use pounds and slugs
and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurementNewton proved his gravity equation by calculating the motion of the moon
devices a huge list to calculate the units for US customers. When you
read this it is very strange that they claim to reach the moon. :-D
in inches, so we can too.
But I and practically everyone with any technical inclination uses
metric in all cases except when an object is involved which was cut in English units by someone else.
In the US, machinists usually say thou and engineers most often say
mils, both meaning 0.001 inches.
Most DEC computers were octal, even the 16-bit PDP-11. I can still
assemble some octal instructions from memory.
What's amazing is that the 6th finger actually works, has veins and
nerves and muscles and tendons and stuff.
John Larkin <jlarkin@highland_atwork_technology.com> wrote:
Surprisingly, some big aerospace companies still use pounds and
slugs and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When
you read this it is very strange that they claim to reach the
moon. :-D
Oh..and it is one of the reason why american cars are not so
popular in Germany.
People wonder how to repair them with strange
threads and unusual tools.
Whenever I read about AWG, 0.5oz copper or number drill sizes I
have to shake my head.
Olaf
On Saturday, February 19, 2022 at 8:39:22 PM UTC-5, Tom Del Rosso
wrote:
olaf wrote:
John Larkin <jlarkin@highland_atwork_technology.com> wrote:Newton proved his gravity equation by calculating the motion of the
Surprisingly, some big aerospace companies still use pounds and
slugs and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When
you read this it is very strange that they claim to reach the moon.
:-D
moon in inches, so we can too.
But I and practically everyone with any technical inclination uses
metric in all cases except when an object is involved which was cut
in English units by someone else.
Yeah, we don't want no one telling us what units to measure in or to
wear masks to keep from dying of a pandemic. Both have worked well
for everyone in this country... except for 959,000.
On Saturday, February 19, 2022 at 6:17:25 AM UTC-5, David Brown
wrote:
On 18/02/2022 23:36, Rick C wrote:
On Friday, February 18, 2022 at 1:51:04 PM UTC-5, whit3rd
wrote:
On Friday, February 18, 2022 at 6:45:50 AM UTC-8,
You mean why do people use the measuring system that everyonePre-NATO, all US military machinery would have been inches;
else in their country use? I guess this is a more pointed
question at the US community. I remember working with a
mechanical engineer at a military contractor and was
surprised they still did everything using inches. 90% of
electronic components are in mm as the primary unit. I guess
I expect the mechanical community would have converted by
now, but, no.
even now, NATO has standard 7.62 mm ammo, which is just a
soft-conversion from .30 caliber...
I would hope you'd understand the difference in changing
nomenclature
and changing measurement systems. Caliber is not an actualI think a key point on units is whether you need to convert them
measurement of anything, rather a nominal use. Same as 12 inch
wafers or a 19 inch rack cabinet. I guess something on a 19
inch rack cabinet is actually 19 inches, but in reality, it's
just a name we use.
or not,
and how they are compared to different measurements. If you need
to convert things into real lengths, weights, or whatever, then
metric is the only sane choice. But often you don't need
conversions.
It doesn't matter if a .44 calibre bullet is 0.44 inches wide or
long, 0.44 kg in weight, or whatever - it's just a name, and as
long as you match up the name used on the gun and the ammo,
you're fine.
It doesn't matter what width a 19" rack is - it just matters that
everyone follows the same standard size. You don't measure the
height of the rack in centimetres - you measure it in "units"
because everything that goes in the rack is an integer number of
"units" in height. If you want to know if your new 4 unit server
will fit in your rack, you count the number of units of space you
have left - conversion
to millimetres or measuring with an inchtape would be silly.
On the other side, the size of your pcb tracks and footprints, or
screw
threads, or mechanical drawings, all need to be as accurate as
practically possible, and all need to be specified in a precise
scale -
metric.
That is an error. There is nothing more precise about metric than
imperial units. It's just a matter of convenience. For some
metric is more convenient because it's what they are used to, but
also the advantages of a decimal based system with few conversion
factors. For others imperial is what they are used to and need to
learn the conversion factors... many conversion factors... many,
many conversion factors. But both are equally precise.
BTW, you need to understand precision.
David Brown wrote:
It is not just important that you use a precise scale - some imperial
scales are as precise as metric. (An inch is formally defined as 25.4
mm.)
Which is sad. They should've made it 2.56mm, then all those power-of-two fractions would divide beautifully into mm.
On 19/02/2022 21:01, Robert Latest wrote:
David Brown wrote:
It is not just important that you use a precise scale - some imperial
scales are as precise as metric. (An inch is formally defined as 25.4
mm.)
Which is sad. They should've made it 2.56mm, then all those power-of-two fractions would divide beautifully into mm.
Yes. But it had to match up with the length of three barley corns.
(The barleycorn is of course still used in shoe sizes.)
Rick C wrote:
On Saturday, February 19, 2022 at 8:39:22 PM UTC-5, Tom Del Rosso
wrote:
olaf wrote:
John Larkin <jlarkin@highland_atwork_technology.com> wrote:Newton proved his gravity equation by calculating the motion of the
Surprisingly, some big aerospace companies still use pounds and
slugs and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When
you read this it is very strange that they claim to reach the moon.
:-D
moon in inches, so we can too.
But I and practically everyone with any technical inclination uses
metric in all cases except when an object is involved which was cut
in English units by someone else.
Yeah, we don't want no one telling us what units to measure in or toI recall saying 2 years ago that everyone could keep going to work if
wear masks to keep from dying of a pandemic. Both have worked well
for everyone in this country... except for 959,000.
they wore masks, and I recall you saying it would not be adequate.
There are some weird exceptions. You'll see hPa because it
happens to be close to 1mbar.
On Sat, 19 Feb 2022 15:27:10 +0100, David Brown
<david.brown@hesbynett.no> wrote:
US decimal points are just as good as metric decimal points. We can
measure inches as accurately as you can measure centimeters.
Does anybody use centimeters? Seems like an orphan unit.
On Sunday, February 20, 2022 at 6:18:26 AM UTC-5, Tom Del Rosso wrote:
Rick C wrote:
On Saturday, February 19, 2022 at 8:39:22 PM UTC-5, Tom Del RossoI recall saying 2 years ago that everyone could keep going to work if
wrote:
olaf wrote:
John Larkin <jlarkin@highland_atwork_technology.com> wrote:Newton proved his gravity equation by calculating the motion of the
Surprisingly, some big aerospace companies still use pounds and
slugs and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When
you read this it is very strange that they claim to reach the
moon. :-D
moon in inches, so we can too.
But I and practically everyone with any technical inclination uses
metric in all cases except when an object is involved which was cut
in English units by someone else.
Yeah, we don't want no one telling us what units to measure in or to
wear masks to keep from dying of a pandemic. Both have worked well
for everyone in this country... except for 959,000.
they wore masks, and I recall you saying it would not be adequate.
And it has not been adequate. What is your point? You did see the
sarcasm in my statement, no?
The mistake I made was thinking there was ever a prayer of hope that
people would actually do what was needed or that we could "get 'er
done" around the world. As it turns out not only are masks not
sufficient, vaccines are not sufficient. With new strains showing up
every few months, we can expect this pandemic to be with us for a
long time. It may turn out that there is selective pressure to be
less virulent, in which case it may end up being no worse than the
flu. At the moment the US is approaching 1 million dead which is
far, far worse than any flu since I was born.
Rick C wrote:
On Sunday, February 20, 2022 at 6:18:26 AM UTC-5, Tom Del Rosso wrote:
Rick C wrote:
On Saturday, February 19, 2022 at 8:39:22 PM UTC-5, Tom Del RossoI recall saying 2 years ago that everyone could keep going to work if
wrote:
olaf wrote:
John Larkin <jlarkin@highland_atwork_technology.com> wrote:Newton proved his gravity equation by calculating the motion of the
Surprisingly, some big aerospace companies still use pounds and
slugs and BTUs and things. Creeps me out.
Yes, it must be a strange live there. We have in our measurement
devices a huge list to calculate the units for US customers. When
you read this it is very strange that they claim to reach the
moon. :-D
moon in inches, so we can too.
But I and practically everyone with any technical inclination uses
metric in all cases except when an object is involved which was cut
in English units by someone else.
Yeah, we don't want no one telling us what units to measure in or to
wear masks to keep from dying of a pandemic. Both have worked well
for everyone in this country... except for 959,000.
they wore masks, and I recall you saying it would not be adequate.
And it has not been adequate. What is your point? You did see theSo we should have been out of work for 2 years.
sarcasm in my statement, no?
The mistake I made was thinking there was ever a prayer of hope thatThe flu kills people who don't have 6 comorbidities. Or cancer like
people would actually do what was needed or that we could "get 'er
done" around the world. As it turns out not only are masks not
sufficient, vaccines are not sufficient. With new strains showing up
every few months, we can expect this pandemic to be with us for a
long time. It may turn out that there is selective pressure to be
less virulent, in which case it may end up being no worse than the
flu. At the moment the US is approaching 1 million dead which is
far, far worse than any flu since I was born.
Powell.
On Sunday, February 20, 2022 at 8:26:38 AM UTC-5, David Brown wrote:
On 19/02/2022 21:01, Robert Latest wrote:
David Brown wrote:Yes. But it had to match up with the length of three barley corns.
It is not just important that you use a precise scale - some
imperial scales are as precise as metric. (An inch is formally
defined as 25.4 mm.)
Which is sad. They should've made it 2.56mm, then all those
power-of-two fractions would divide beautifully into mm.
(The barleycorn is of course still used in shoe sizes.)
Barleycorns aside, it was more about matching the inch. The
definition of the inch has a long and tortuous history, but in 1866
the US defined it as 39.37 to a meter, just off from 2.54 cm by about
two ppm. Not many uses were impacted by two ppm, so 2.54 cm to the
inch was later adopted largely because it had become commercial
practice.
On 2022-02-19, jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:
On Sat, 19 Feb 2022 15:27:10 +0100, David Brown
<david.brown@hesbynett.no> wrote:
US decimal points are just as good as metric decimal points. We can
measure inches as accurately as you can measure centimeters.
Does anybody use centimeters? Seems like an orphan unit.
It's mainly used for measuring people, so clothing dimensions, describing
how tall someone is. That sort of thing.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. Ifthe layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.
I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that cantrigger the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or
On 18/02/2022 21:45, Rick C wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
the layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.
I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If
trigger the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or
I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that can
The USA is at war with the decimal system. An fraction of an inch is not
0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not 10 inches.
In the 1980s they promised to go metric, like the British did. Yeah, right.
They don't want to fit in the world. They want the world to fit around them.
Werner Dahn
The USA is at war with the decimal system. An fraction of an inch
is not 0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is
not 10 inches.
In the 1980s they promised to go metric, like the British did.
Yeah, right.
They don't want to fit in the world. They want the world to fit
around them.
Werner Dahn
On Mon, 21 Feb 2022 18:16:42 +0700, aioe usenet <hirni47@yahoo.com>
wrote:
The USA is at war with the decimal system. An fraction of an inch is not
0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not 10 inches. >>
In the 1980s they promised to go metric, like the British did. Yeah, right. >>
They don't want to fit in the world. They want the world to fit around them. >>
Werner Dahn
We do science and engineering in SI units.
Pounds, ounces, inches, feet, miles, pints, gallons, degrees F are
familiar and convenient everyday units. Nothing wrong with that.
Converting to metric was unpopular, so it wasn't forced.
On 21/02/2022 14:36, jlarkin@highlandsniptechnology.com wrote:
On Mon, 21 Feb 2022 18:16:42 +0700, aioe usenet <hirni47@yahoo.com>
wrote:
The USA is at war with the decimal system. An fraction of an inch is not >>> 0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not 10 inches. >>>
In the 1980s they promised to go metric, like the British did. Yeah, right. >>>
They don't want to fit in the world. They want the world to fit around them.
Werner Dahn
We do science and engineering in SI units.
Pounds, ounces, inches, feet, miles, pints, gallons, degrees F are
familiar and convenient everyday units. Nothing wrong with that.
Converting to metric was unpopular, so it wasn't forced.
A change like that is always hard, and therefore unpopular. But it
typically gets harder the longer you wait.
Part of the job of a government is to do things that are unpopular, but
are nonetheless the right move in the long run.
governments are getting worse at that, with the USA in the lead but not
alone - politicians are unwilling to risk their current popularity by
making long-term investments where the benefits will be reaped by later >politicians. The American system of presidents from alternating parties >whose main focus seems to be undoing everything from the previous
presidency, makes it even harder to make major long-term changes.
An exception to this trend is Brexit - there the UK government /was/
willing to go through very significant cost and hardship for long-term >change. Unfortunately the short-term cost and hardship is a sacrifice >leading to longer-term cost and hardship - change is perhaps inevitable,
but progress is not.
The British went through the change to metric (keeping pints for beer
and milk, which is fine). They went through a change in currency in
about 1971, from silly pounds / shillings / pence to a decimal system.
It can be done, and it is worth doing.
Maybe a deal can be made - the USA changes its outdated measurement
system, its daft paper sizes, and its non-standard mains electricity.
In return, the British will accept "color", "analog" and "neighbor" as >acceptable spelling :-)
The British went through the change to metric (keeping pints for beer
and milk, which is fine). They went through a change in currency in
about 1971, from silly pounds / shillings / pence to a decimal system.
It can be done, and it is worth doing.
Maybe a deal can be made - the USA changes its outdated measurement
system, its daft paper sizes, and its non-standard mains electricity.
In return, the British will accept "color", "analog" and "neighbor" as acceptable spelling :-)
On Monday, February 21, 2022 at 6:18:17 AM UTC-5, aioe usenet wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On 18/02/2022 21:45, Rick C wrote:
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote: >> >> On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell
right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.
I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If the
the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or something. I don'
I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that can trigger
The USA is at war with the decimal system. An fraction of an inch is not
0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not 10 inches.
Don't confuse decimal with imperial or metric. The binary fractions are a common use of inches, but it is far from universal. Virtually any use of inches other than personal usage is decimal inches.
here are more comfortable with Imperial. We happily buy our liquor in metric. That industry simply converted and is done with "fifths" and half pints, etc. Beer is commonly sold by ounces though. I'm currently drinking a soft drink in a tall skinnyIn the 1980s they promised to go metric, like the British did. Yeah, right.
I don't think the US ever made any promises. The efforts to metrify were always voluntary. We have become a dual measurement country. But habits are hard to change. We have supermarket products labeled in both Imperial and metric, but most people
the US for international products, just like from other countries, have dual labels for metric and Imperial. So we are doing what we must to fit in. If or when the international convention for data sheets becomes metric only, our data sheets will stillThey don't want to fit in the world. They want the world to fit around them.
I think few people from outside the US can appreciate the level of isolation in the US. Yeah, we can pretty much live fat, dumb and happy with the Imperial system in everyday use. However, anything international has to include metric. Data sheets in
It is my hope that someday we will convert, but there is literally no pain in staying with our current system. None that the typical voter sees anyway. So politicians are not going to push the issue.
How does this affect anyone outside the US? If the US converted to metric measurements today, 100%, what would change for you?
On 18/02/2022 21:45, Rick C wrote:did everything using inches. 90% of electronic components are in mm as the primary unit. I guess I expect the mechanical community would have converted by now, but, no.
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen Belleman wrote:
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia Else:Designed to confuse. Why do people do that?
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both imperial and
metric sizes? No wonder there's no way I can put my imperial 0603
components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and I fell >>>> right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone else in their country use? I guess this is a more pointed question at the US community. I remember working with a mechanical engineer at a military contractor and was surprised they still
layout was done by someone else, maybe not so much. I like doing layouts. It's like puzzle solving.I seem to recall an imperial 0603 is a metric 1608. The places where I would be selecting a part they make it clear which size they are using. On layout I would notice the difference in size, 2.5 to 1. I'm a bit surprised this error was made. If the
the alarms at PCB house pricing software and put you in a higher price category. I remember seeing feature checking software that would sound the alarm at what I can only assume was round off error missing the target by 0.00001 inches or something. I don'I don't get why mil are still used in PCB layout so much. Layer thickness is still done in mil. Trace/space is still commonly in mil. I typically do my layout in mm. 6 mil is 0.1524 mm, so that gets rounded to 0.15 mm. Unfortunately that can trigger
The USA is at war with the decimal system. An fraction of an inch is not
0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not 10 inches.
In the 1980s they promised to go metric, like the British did. Yeah, right.
They don't want to fit in the world. They want the world to fit around them.
Assuming that a ruling elite can ignore the preferences of the dumb
flyover populace who, for some bizarre reason, are allowed to vote.
On Monday, February 21, 2022 at 9:08:07 AM UTC-5, David Brown wrote:
The British went through the change to metric (keeping pints for
beer and milk, which is fine). They went through a change in
currency in about 1971, from silly pounds / shillings / pence to a
decimal system. It can be done, and it is worth doing.
I've always though the British monetary units were cute. How about a
Bob, Guv? I still can't remember how much a crown is, but it sounds interesting.
The guinea is the one that really gets me though,
£1/1/-. Who invented that!? Apparently it arose from the fact it
was gold and intended to be 20 shillings, but the shilling was in
silver and the relative value varied. At some point the guinea was standardized to be worth 21 shillings (the relative value at the
time) and the oddness was born!
Maybe a deal can be made - the USA changes its outdated measurement
system, its daft paper sizes, and its non-standard mains
electricity. In return, the British will accept "color", "analog"
and "neighbor" as acceptable spelling :-)
English is the common language that divides us.
A
shilling was two sixpences, each of which was two thrupences or three tuppences.
...
On the other hand, you have some cases where the word is the same, but
you've got the meaning completely wrong. And you can't pronounce
"route" correctly - for some reason, that one always bugs me.
On Monday, February 21, 2022 at 6:18:17 AM UTC-5, aioe usenet
wrote:
On 18/02/2022 21:45, Rick C wrote::
On Friday, February 18, 2022 at 6:01:25 AM UTC-5, Jeroen
Belleman wrote
On 2022-02-18 11:11, Lasse Langwadt Christensen wrote:
fredag den 18. februar 2022 kl. 09.32.02 UTC+1 skrev Sylvia
Else:
I've got a board made that includes pads for some 0603 smds.
How was I expected to know that 0603 is used for both
imperial and
metric sizes? No wonder there's no way I can put my imperial
0603 components onto the metric 0603 landing pads.
0603 appears to be the only size where this trap arises, and
I fell
heir country use? I guess this is a more pointed question at theDesigned to confuse. Why do people do that?right into it.
also 0402 metric which is 01005 imperial
You mean why do people use the measuring system that everyone
else in t
US community. I remember working with a mechanical engineer at a
military contractor and was surprised they still did everything
using inches. 90% of electronic components are in mm as the
primary unit. I guess I expect the mechanical community would have
converted by now, but, no.
would be selecting a part they make it clear which size they are
I seem to recall an imperial 0603 is a metric 1608. The places
where I
using. On layout I would notice the difference in size, 2.5 to 1.
I'm a bit surprised this error was made. If the layout was done by
someone else, maybe not so much. I like doing layouts. It's like
puzzle solving.
ss is still done in mil. Trace/space is still commonly in mil. I
I don't get why mil are still used in PCB layout so much. Layer
thickne
typically do my layout in mm. 6 mil is 0.1524 mm, so that gets
rounded to 0.15 mm. Unfortunately that can trigger the alarms at
PCB house pricing software and put you in a higher price category.
I remember seeing feature checking software that would sound the
alarm at what I can only assume was round off error missing the
target by 0.00001 inches or something. I don't think I ever used
that PWB supplier. I can't imagine what it would take to get that
through their system. There were dozens if not hundreds of such
error reports.
The USA is at war with the decimal system. An fraction of an inch
is not
0.x but x/[2 or 4 or 8 or a multiple thereof] and a foot is not.
10 inches
Don't confuse decimal with imperial or metric. The binary
fractions are a common use of inches, but it is far from
universal. Virtually any use of inches other than personal usage
is decimal inches.
In the 1980s they promised to go metric, like the British did.t.
Yeah, righ
I don't think the US ever made any promises. The efforts to
metrify were always voluntary. We have become a dual measurement
country. But habits are hard to change. We have supermarket
products labeled in both Imperial and metric, but most people here
are more comfortable with Imperial. We happily buy our liquor in
metric. That industry simply converted and is done with "fifths"
and half pints, etc. Beer is commonly sold by ounces though. I'm
currently drinking a soft drink in a tall skinny can that is 330
ml/11.15 fl oz.
They don't want to fit in the world. They want the world to fitem.
around th
I think few people from outside the US can appreciate the level of
isolation in the US. Yeah, we can pretty much live fat, dumb and
happy with the Imperial system in everyday use. However, anything international has to include metric. Data sheets in the US for
international products, just like from other countries, have dual
labels for metric and Imperial. So we are doing what we must to
fit in. If or when the international convention for data sheets
becomes metric only, our data sheets will still include metric
values, so we will be compatible.
It is my hope that someday we will convert, but there is literally
no pain in staying with our current system. None that the typical
voter sees anyway. So politicians are not going to push the
issue.
How does this affect anyone outside the US? If the US converted
to metric measurements today, 100%, what would change for you?
On 21/02/2022 17:00, David Brown wrote:
<snip>
A
shilling was two sixpences, each of which was two thrupences or
three tuppences.
Very valuable nowadays, those tuppences.
Is there a meaning to what you posted? Or is it just some random
thought you had and felt the need to share with us like some derelict
on a street corner?
David Brown wrote:
...
On the other hand, you have some cases where the word is the same, but
you've got the meaning completely wrong. And you can't pronounce
"route" correctly - for some reason, that one always bugs me.
Look, just because we don't go kicking our rooters every time the
internet goes out ... :)
| Sysop: | Keyop |
|---|---|
| Location: | Huddersfield, West Yorkshire, UK |
| Users: | 231 |
| Nodes: | 16 (3 / 13) |
| Uptime: | 106:24:46 |
| Calls: | 4,951 |
| Files: | 11,523 |
| Messages: | 3,984,610 |
