• sharpening end mills

    From Snag@21:1/5 to All on Thu Dec 8 23:22:32 2022
    I've got a bunch that have chipped tips on the flutes , and I
    guess it's time I learned to sharpen them instead of tossing them and
    buying more .I've poked around a little and found a design for a fixture
    using 5C collets that I can build with tooling I have on hand . I do
    have a question about using my mill to grind these . It doesn't spin as
    fast a a real grinder , about 1800 RPM tops IIRC . I'm looking for
    suggestions what type of wheel I need . Probably a cup wheel since the
    end mill will mount with the tip up .

    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Jim Wilkins@21:1/5 to All on Fri Dec 9 07:28:34 2022
    "Snag" wrote in message news:tmugmi$13efh$1@dont-email.me...

    I've got a bunch that have chipped tips on the flutes , and I
    guess it's time I learned to sharpen them instead of tossing them and
    buying more .I've poked around a little and found a design for a fixture
    using 5C collets that I can build with tooling I have on hand . I do
    have a question about using my mill to grind these . It doesn't spin as
    fast a a real grinder , about 1800 RPM tops IIRC . I'm looking for
    suggestions what type of wheel I need . Probably a cup wheel since the
    end mill will mount with the tip up .
    Snag

    ---------------------

    This type of fixture works well enough for me, on my ancient $100 surface grinder. https://www.grizzly.com/products/grizzly-end-mill-grinding-fixture/g9887
    I have the Enco version with 24 click stops, no dial or lock screw. The base was cut square and the relief angle is in the mounting hole for the ring
    that retains the collet holder. If I'd tried to make it I might have had trouble matching the collet taper, the rest is pretty simple and the tilt angles shouldn't need to be exact, eyeball alignment in the collet and on
    the grinder mag chuck is good enough to make an endmill cut well. I did
    machine another collet closer nut that accepts flanged bushings to center an S&D drill bit, etc.

    It isn't obvious that the end cutting edges angle in slightly toward the center. If you are set on making your own I can measure the collet holder's lengthwise and sideways tilt angles on mine.

    In addition to sharpening the ends normally it can grind worn tips into a 30 degree bevel to cut sideways without dulling the spiral edges. I have one
    old 1/2" 4-flute that I grind that way and use for roughing, to save the
    other endmills for finishing. Another scheme to preserve the spiral edges is
    to rough with plunge cuts which dull only the end edges that I can easily regrind.

    I also have a fixture like this to sharpen the spiral edges: https://www.shars.com/end-mill-cutter-and-sharpener
    It's quite fussy to set up and use, and it reduces the diameter which can be useful to cut a slot to 0.500" (with multiple passes or another new endmill) instead of slightly larger from deflection, but is otherwise a nuisance
    since they look the same.
    I made it more rigid by removing the tilt mechanism that would swing the endmill into or away from a cup wheel, since I grind on the top with a
    normal 6" wheel.

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  • From Jim Wilkins@21:1/5 to All on Fri Dec 9 09:01:38 2022
    "Jim Wilkins" wrote in message news:tmv9mu$157ci$1@dont-email.me...
    ...
    In addition to sharpening the ends normally it can grind worn tips into a 30 degree bevel to cut sideways without dulling the spiral edges.
    ...

    ----------------

    If that isn't clear, the fixture is tilted onto the 25 degree (I measured
    it) angled face and the chipped end mill tip is ground back at that angle
    like the cutting edge of a drill bit. It will cut as long as the least
    chipped corner has been sharpened, and eventually regrinding may restore others. You can grind a badly chipped one back to square with a bench or
    angle grinder and restore the cutting edge geometry with the fixture. 4
    flute endmills can be salvaged although they are unlikely to remain center cutting, 2 flute ones are easier.

    Based on my mill's somewhat limited rigidity I grind the dull point back
    about 0.025" or less lengthwise, leaving at least half the diameter cutting flat, and alternate between regrinding it square or beveled. Both edge faces wear from roughing by plunge cuts. The beveled cutting edges seem much less vulnerable to chipping in mystery metal with hard spots.

    I would be extremely careful to keep grit off the exposed ways of a mill.
    The ways of a surface grinder are shielded.

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  • From Snag@21:1/5 to Jim Wilkins on Fri Dec 9 07:40:32 2022
    On 12/9/2022 6:28 AM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tmugmi$13efh$1@dont-email.me...

      I've got a bunch that have chipped tips on the flutes , and I
     guess it's time I learned to sharpen them instead of tossing them and buying more .I've poked around a little and found a design for a fixture
     using 5C collets that I can build with tooling I have on hand . I do
    have a question about using my mill to grind these . It doesn't spin as
    fast a a real grinder , about 1800 RPM tops IIRC . I'm looking for suggestions what type of wheel I need . Probably a cup wheel since the
    end mill will mount with the tip up .
    Snag

    ---------------------

    This type of fixture works well enough for me, on my ancient $100
    surface grinder. https://www.grizzly.com/products/grizzly-end-mill-grinding-fixture/g9887
    I have the Enco version with 24 click stops, no dial or lock screw. The
    base was cut square and the relief angle is in the mounting hole for the
    ring that retains the collet holder. If I'd tried to make it I might
    have had trouble matching the collet taper, the rest is pretty simple
    and the tilt angles shouldn't need to be exact, eyeball alignment in the collet and on the grinder mag chuck is good enough to make an endmill
    cut well. I did machine another collet closer nut that accepts flanged bushings to center an S&D drill bit, etc.

    It isn't obvious that the end cutting edges angle in slightly toward the center. If you are set on making your own I can measure the collet
    holder's lengthwise and sideways tilt angles on mine.

    In addition to sharpening the ends normally it can grind worn tips into
    a 30 degree bevel to cut sideways without dulling the spiral edges. I
    have one old 1/2" 4-flute that I grind that way and use for roughing, to
    save the other endmills for finishing. Another scheme to preserve the
    spiral edges is to rough with plunge cuts which dull only the end edges
    that I can easily regrind.

    I also have a fixture like this to sharpen the spiral edges: https://www.shars.com/end-mill-cutter-and-sharpener
    It's quite fussy to set up and use, and it reduces the diameter which
    can be useful to cut a slot to 0.500" (with multiple passes or another
    new endmill) instead of slightly larger from deflection, but is
    otherwise a nuisance since they look the same.
    I made it more rigid by removing the tilt mechanism that would swing the endmill into or away from a cup wheel, since I grind on the top with a
    normal 6" wheel.


    The Griz unit is the one I plan to try to duplicate . The shars unit
    is discontinued but I seldom dull the sides . Knowing the angles
    involved would be a big help ...
    I'm still wondering what type of grinding wheel I need for the RPM's
    my mill has .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Snag@21:1/5 to Jim Wilkins on Fri Dec 9 09:55:00 2022
    On 12/9/2022 8:01 AM, Jim Wilkins wrote:
    "Jim Wilkins"  wrote in message news:tmv9mu$157ci$1@dont-email.me...
    ...
    In addition to sharpening the ends normally it can grind worn tips into
    a 30
    degree bevel to cut sideways without dulling the spiral edges.
    ...

    ----------------

    If that isn't clear, the fixture is tilted onto the 25 degree (I
    measured it) angled face and the chipped end mill tip is ground back at
    that angle like the cutting edge of a drill bit. It will cut as long as
    the least chipped corner has been sharpened, and eventually regrinding
    may restore others. You can grind a badly chipped one back to square
    with a bench or angle grinder and restore the cutting edge geometry with
    the fixture. 4 flute endmills can be salvaged although they are unlikely
    to remain center cutting, 2 flute ones are easier.

    Based on my mill's somewhat limited rigidity I grind the dull point back about 0.025" or less lengthwise, leaving at least half the diameter
    cutting flat, and alternate between regrinding it square or beveled.
    Both edge faces wear from roughing by plunge cuts. The beveled cutting
    edges seem much less vulnerable to chipping in mystery metal with hard
    spots.



    I would be extremely careful to keep grit off the exposed ways of a
    mill. The ways of a surface grinder are shielded.


    That's what old sheets are for ... OK , so after watching some Joe Py
    video I went ahead and ordered a 6" bonded grit saw blade sharpening
    wheel . It should work well as long as I don't get too frisky with feed
    rates . This project will go on the back burner for now , got other
    stuff that's more pressing - like getting the new gears installed in my
    truck axle . I can't finish carb/timing/etc tuning until that's done .
    And I can't do that until I get my neighbor's 4X4 UTV finished . Maybe
    today on that one , almost finished reassembly after replacing a set of
    bevel gears deep inside the guts . Had to split the cases to get to the
    damaged gears .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Bob La Londe@21:1/5 to Snag on Fri Dec 9 10:23:04 2022
    On 12/8/2022 10:22 PM, Snag wrote:
      I've got a bunch that have chipped tips on the flutes , and I
     guess it's time I learned to sharpen them instead of tossing them and buying more .I've poked around a little and found a design for a fixture
     using 5C collets that I can build with tooling I have on hand . I do
    have a question about using my mill to grind these . It doesn't spin as
    fast a a real grinder , about 1800 RPM tops IIRC . I'm looking for suggestions what type of wheel I need . Probably a cup wheel since the
    end mill will mount with the tip up .


    Since I do mostly CNC its not worth it to me generally, but I do have a
    diamond cut off wheel for the TC grinder so I can lop off the chowdered
    tips of a carbide mill and use it strictly for side milling. I don't
    have much in the way of HSS mills. Most of them are still on the floor
    where I threw that harbor Freight box six months ago.

    That being said I have purchased resharpened a couple times when I
    needed a particular geometry for a single job and didn't want to spend a
    lot on it. There is a sharpening outfit in Phoenix that used to have
    tons of resharpened mills on Ebay pretty cheap.



    --
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  • From Jim Wilkins@21:1/5 to All on Fri Dec 9 12:25:06 2022
    Projects, projects, ...

    AFAICT with limited equipment the collet tilt angles are 5 degrees toward
    the beveled end and 2 degrees to the left with the bevel toward you (or me).
    At least those angle blocks visually match it to a square. I confirmed that
    the bevel is 25 degrees from the base.

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  • From Jim Wilkins@21:1/5 to All on Fri Dec 9 12:39:27 2022
    "Snag" wrote in message news:tmvdsa$15i01$1@dont-email.me...

    I'm still wondering what type of grinding wheel I need for the RPM's
    my mill has .

    ----------

    I doubt that it matters all that much if you aren't in production, grinding works down to hand honing speed. https://www.ebay.com/b/Crank-Grinder-In-other-Collectible-Tools/1461/bn_7022913747

    The normal speed of my surface grinder burns carbon steel jointer blades
    unless I take -very- light passes.

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  • From Snag@21:1/5 to Jim Wilkins on Fri Dec 9 15:04:34 2022
    On 12/9/2022 11:25 AM, Jim Wilkins wrote:
    Projects, projects, ...

    AFAICT with limited equipment the collet tilt angles are 5 degrees
    toward the beveled end and 2 degrees to the left with the bevel toward
    you (or me). At least those angle blocks visually match it to a square.
    I confirmed that the bevel is 25 degrees from the base.




    Thanks , those are pretty close to the numbers I expected . One more
    good day on the neighbor's machine should see it back in running shape ,
    the motor's ready to drop in now .
    I originally told the neighbor that I would do his after I finished
    the truck ... I relented and moved it up because his wife was making him miserable over it . She's one of those "corporate movers and shakers" .
    I'm sure glad I married a "simple country girl" !
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Jim Wilkins@21:1/5 to All on Sat Dec 10 18:22:27 2022
    "Snag" wrote in message news:tn07ss$1asq8$1@dont-email.me...

    Thanks , those are pretty close to the numbers I expected . One more
    good day on the neighbor's machine should see it back in running shape ,
    the motor's ready to drop in now .
    I originally told the neighbor that I would do his after I finished
    the truck ... I relented and moved it up because his wife was making him miserable over it . She's one of those "corporate movers and shakers" .
    I'm sure glad I married a "simple country girl" !
    Snag

    -------------------
    My day's project was lost to helping an elderly neighbor too. Everything
    went wrong, and it's reassuring that in my mid 70's I can still diagnose and fix problems quickly.

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  • From Snag@21:1/5 to Jim Wilkins on Sat Dec 10 18:41:04 2022
    On 12/10/2022 5:22 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tn07ss$1asq8$1@dont-email.me...

    Thanks , those are pretty close to the numbers I expected . One more
    good day on the neighbor's machine should see it back in running shape ,
    the motor's ready to drop in now .
      I originally told the neighbor that I would do his after I finished
    the truck ... I relented and moved it up because his wife was making him miserable over it . She's one of those "corporate movers and shakers" .
    I'm sure glad I married a "simple country girl" !
    Snag

    ------------------- My day's project was lost to helping an elderly
    neighbor too. Everything went wrong, and it's reassuring that in my mid
    70's I can still diagnose and fix problems quickly.


    Kids now days , if they can't read the problem off a computer screen
    they're totally lost . Remember Gus from Popular Mechanics (IIRC) back
    in the 50's-60's ? His column taught me to diagnose a burned exhaust
    valve by sticking a strip of paper to the end of the exhaust pipe with bubblegum ...
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Bob La Londe@21:1/5 to Snag on Sun Dec 11 10:39:17 2022
    On 12/10/2022 5:41 PM, Snag wrote:
    On 12/10/2022 5:22 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tn07ss$1asq8$1@dont-email.me...

    Thanks , those are pretty close to the numbers I expected . One more
    good day on the neighbor's machine should see it back in running shape ,
    the motor's ready to drop in now .
       I originally told the neighbor that I would do his after I finished
    the truck ... I relented and moved it up because his wife was making him
    miserable over it . She's one of those "corporate movers and shakers" .
    I'm sure glad I married a "simple country girl" !
    Snag

    ------------------- My day's project was lost to helping an elderly
    neighbor too. Everything went wrong, and it's reassuring that in my
    mid 70's I can still diagnose and fix problems quickly.


      Kids now days , if they can't read the problem off a computer screen they're totally lost . Remember Gus from Popular Mechanics (IIRC) back
    in the 50's-60's ? His column taught me to diagnose a burned exhaust
    valve by sticking a strip of paper to the end of the exhaust pipe with bubblegum ...


    Speaking of off the computer screen. There is a YouTuber who uses his
    mill fairly often as a grinder you might find interesting. Its not
    typically a "grinding" video, but instead one part of a project. He did
    a fair amount of grinding in a video about making a grinder vise
    (screwless vise). In a more recent video he touched on mill grinding
    when making a case hardened gear. He also does a bit of case hardening.

    Artisan Makes

    Aside: I currently use modified grinder vises as my primary fixturing attachment on 4 mills because they take up less space for their range
    than a mill vise, and they are more flexible than a fixture plate. (I
    Use fixture plates too. Some mount in the vises as needed.)

    Back on topic: I suppose I should have put this out there sooner. There
    are two answers that come to mind for me about your concerns for speed.
    (1) A larger wheel gives more surface speed. (2) Grinding slower works
    fine. Its just slower. For example a Tormec knife grinder is an order
    of magnitude slower than a bench grinder or most other machine shop
    grinding machines.



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  • From Snag@21:1/5 to Bob La Londe on Sun Dec 11 12:55:57 2022
    On 12/11/2022 11:39 AM, Bob La Londe wrote:
    On 12/10/2022 5:41 PM, Snag wrote:
    On 12/10/2022 5:22 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tn07ss$1asq8$1@dont-email.me...

    Thanks , those are pretty close to the numbers I expected . One more
    good day on the neighbor's machine should see it back in running shape , >>> the motor's ready to drop in now .
       I originally told the neighbor that I would do his after I finished >>> the truck ... I relented and moved it up because his wife was making him >>> miserable over it . She's one of those "corporate movers and shakers" .
    I'm sure glad I married a "simple country girl" !
    Snag

    ------------------- My day's project was lost to helping an elderly
    neighbor too. Everything went wrong, and it's reassuring that in my
    mid 70's I can still diagnose and fix problems quickly.


       Kids now days , if they can't read the problem off a computer
    screen they're totally lost . Remember Gus from Popular Mechanics
    (IIRC) back in the 50's-60's ? His column taught me to diagnose a
    burned exhaust valve by sticking a strip of paper to the end of the
    exhaust pipe with bubblegum ...


    Speaking of off the computer screen.  There is a YouTuber who uses his
    mill fairly often as a grinder you might find interesting. Its not
    typically a "grinding" video, but instead one part of a project.  He did
    a fair amount of grinding in a video about making a grinder vise
    (screwless vise).  In a more recent video he touched on mill grinding
    when making a case hardened gear.  He also does a bit of case hardening.

    Artisan Makes

    Aside:  I currently use modified grinder vises as my primary fixturing attachment on 4 mills because they take up less space for their range
    than a mill vise, and they are more flexible than a fixture plate.  (I
    Use fixture plates too.  Some mount in the vises as needed.)

    Back on topic: I suppose I should have put this out there sooner.  There
    are two answers that come to mind for me about your concerns for speed.
    (1) A larger wheel gives more surface speed.  (2) Grinding slower works fine.  Its just slower.  For example a Tormec knife grinder is an order
    of magnitude slower than a bench grinder or most other machine shop
    grinding machines.




    I chose the 6" saw grinder wheel partly because it has 1 1/2 times
    the surface speed of a 4" cup . And partly because it was fairly cheap ,
    and partly because of the profile . With the right setup I can gash with
    it too .
    I've been pondering the base for the fixture to mount the end mills .
    I think I'll make the bottom angles and have the sides and ends square
    with them . Then put the 2° bevel on top with the thru hole
    perpendicular to the top . Just seems like the easiest way to me .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Jim Wilkins@21:1/5 to All on Sun Dec 11 18:04:02 2022
    "Snag" wrote in message news:tn5940$2098c$1@dont-email.me...
    ..
    I've been pondering the base for the fixture to mount the end mills .
    I think I'll make the bottom angles and have the sides and ends square
    with them . Then put the 2° bevel on top with the thru hole
    perpendicular to the top . Just seems like the easiest way to me .
    Snag

    ---------------------

    I set the end mill fixture on my mill with the collet upright, 1/2" rod in
    the fixture and spindle collets, raised the table to contact with the back right corner, then pushed a 1/4" thick bar into the wedge space underneath
    from the front (bevel) side. The bar intersects the left side 2.05" from the back and the right side 2.95" from the back. A squared rectangular base
    block could be clamped to a mill table or lathe faceplate this way and bored straight in to get both 2 and 5 degree angles easily.

    I might attach the 1/4" angled spacer with countersunk screws to reduce fumbling and let the setup be accurately repeated later.
    jsw

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  • From Snag@21:1/5 to Jim Wilkins on Sun Dec 11 22:35:09 2022
    On 12/11/2022 5:04 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tn5940$2098c$1@dont-email.me...
    ..
      I've been pondering the base for the fixture to mount the end mills .
    I think I'll make the bottom angles and have the sides and ends square
    with them . Then put the 2° bevel on top with the thru hole
    perpendicular to the top . Just seems like the easiest way to me .
    Snag

    ---------------------

    I set the end mill fixture on my mill with the collet upright, 1/2" rod
    in the fixture and spindle collets, raised the table to contact with the
    back right corner, then pushed a 1/4" thick bar into the wedge space underneath from the front (bevel) side. The bar intersects the left side 2.05" from the back and the right side 2.95" from the back. A squared rectangular base block could be clamped to a mill table or lathe
    faceplate this way and bored straight in to get both 2 and 5 degree
    angles easily.

    I might attach the 1/4" angled spacer with countersunk screws to reduce fumbling and let the setup be accurately repeated later.
    jsw


    I'm going to have to take a minute to digest that ... OK , if I'm understanding this correctly I'll only have to cut one angle on the
    bottom , the other two will be produced by the way the hole for the
    collet is bored in the block - 2° tilt to the rear , 5° to the right .
    If I put a couple of degree angle on the left end I can set the fixture
    up to do the gash with the end mill horizontal/angled slightly down .
    It's been a long day , and I do enjoy a few shots of sour mash in the evening . It's been a gloomy day here , fine drizzle most of the day .
    The dog and I both hate being cooped up inside all day .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Jim Wilkins@21:1/5 to Jim Wilkins on Mon Dec 12 07:41:49 2022
    "Snag" wrote in message news:tn6b20$25j6e$1@dont-email.me...

    On 12/11/2022 5:04 PM, Jim Wilkins wrote:
    "Snag" wrote in message news:tn5940$2098c$1@dont-email.me...
    ..
    I've been pondering the base for the fixture to mount the end mills .
    I think I'll make the bottom angles and have the sides and ends square
    with them . Then put the 2° bevel on top with the thru hole
    perpendicular to the top . Just seems like the easiest way to me .
    Snag

    ---------------------

    I set the end mill fixture on my mill with the collet upright, 1/2" rod in the fixture and spindle collets, raised the table to contact with the back right corner, then pushed a 1/4" thick bar into the wedge space underneath from the front (bevel) side. The bar intersects the left side 2.05" from
    the back and the right side 2.95" from the back. A squared rectangular
    base block could be clamped to a mill table or lathe faceplate this way
    and bored straight in to get both 2 and 5 degree angles easily.

    I might attach the 1/4" angled spacer with countersunk screws to reduce fumbling and let the setup be accurately repeated later.
    jsw


    I'm going to have to take a minute to digest that ... OK , if I'm understanding this correctly I'll only have to cut one angle on the
    bottom , the other two will be produced by the way the hole for the
    collet is bored in the block - 2° tilt to the rear , 5° to the right .
    If I put a couple of degree angle on the left end I can set the fixture
    up to do the gash with the end mill horizontal/angled slightly down .
    It's been a long day , and I do enjoy a few shots of sour mash in the evening . It's been a gloomy day here , fine drizzle most of the day .
    The dog and I both hate being cooped up inside all day .
    Snag

    ---------------------

    Yes, the angled 1/4" spacer tilts the base block to the 2 degree sideways
    and 5 degree lengthwise angles, or at least it will duplicate the angles of mine with only simple length measurements. If you fit it to the base block before milling the 25 degree bevel you can screw it down in the area that
    will be removed.

    However it won't allow very secure clamping, so if you want to go that way
    I'll have to find out how far you can rough drill and bore the collet holder recess with the base block clamped squarely and solidly in a milling vise.
    Then you'll have to re-locate the center in the rough hole when it's clamped
    at the angle, perhaps with a sheet metal template of the base with the
    center punched. You could clamp stuff around it to help keep it from
    twisting out of place from the cutting force.

    You only have to mill the 25° (degree) bevel which can be done with the base block clamped solidly in the vise. Do you have an angle block set? Mine is a much cheaper Enco version of this: https://www.mscdirect.com/product/details/01718360

    Before MSC bought them, Enco had a retail store in southern NH (no sales
    tax) so I stocked up on everything I might need.
    jsw

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  • From Jim Wilkins@21:1/5 to All on Mon Dec 12 10:16:19 2022
    "Jim Wilkins" wrote in message news:tn77jp$27nid$1@dont-email.me...

    I'm going to have to take a minute to digest that ... OK , if I'm understanding this correctly I'll only have to cut one angle on the
    bottom , the other two will be produced by the way the hole for the
    collet is bored in the block - 2° tilt to the rear , 5° to the right .
    If I put a couple of degree angle on the left end I can set the fixture
    up to do the gash with the end mill horizontal/angled slightly down .
    Snag

    -------------
    I don't understand the last sentence.

    Facing the base bevel, the collet tilts 5 degrees toward you and 2 degrees
    to the left. Conversely the way I have it in the mill with the collet
    vertical, the base tilts up toward me and on the left side, which is why the 1/4" parallel jammed under it is at an angle. The easy way to copy that
    angle is to duplicate the distances from the bar to the back of the base
    block on both sides, assuming you make the block the same width as mine, 2.5053".

    The 5 degree tilt provides back relief to the cutting edge, the 2 degree
    dishes the edges inward slightly so only the tips cut, even as they dull. I don't think either angle is critical, recommendations I've seen for back
    relief are a range that almost always includes 5 degrees. Likewise grinding while on the 25 degree base bevel merely removes the bulk of flute material behind the cutting edge, or balances it if you ground most away faster on a bench grinder. Surface grinder wheels can explode if you try to force too
    heavy a cut, I've been nearby on another machine when a kid did that.

    I think you can make all cuts with the end mill or boring head vertical, and
    do most of the machining on the base with it square or single-angled in the vise. On my mill the head can be tilted and swiveled to bore the angled
    collet recess directly, with the base in the milling vise, though squaring (tramming) it up again afterwards is a lot of trouble since the round ram shifts when the clamps are tightened. http://www.lathes.co.uk/clausing%20vertical/img0.gif

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  • From Jim Wilkins@21:1/5 to All on Mon Dec 12 12:54:21 2022
    I took my endmill fixture apart to measure the stock size you'd need to copy it. This is the same design: https://www.penntoolco.com/precise-end-mill-grinding-fixture-5-c-collet-capacity-emf-100/

    The base is 1" thick by 2.5" wide by 4.5" long.
    The collet holder is rod stock at least 1.85" diameter by 2.75" long.
    Its retaining ring is 2.375" diameter by 12mm thick (plate stock?). It fits into the angled bore in the base block.
    The collet closer nut is a little under 1.5" diameter.
    The 3 indexing balls are .187" diameter, with similar sized compression springs.

    The collet holder has a circle of 24 indexing dimples in the flanged lower
    end.

    The holes for the index balls and springs were drilled while the block was tilted, so you may have to center it on a rotary index table with the 1/4" spacer in place. Likewise the 3 screws that attach the collet retaining ring were angled through the base, thus square into the ring, and countersunk at
    the angle from the bottom side, which may be tricky.

    The Grizzly G9887 is on sale for $61.15.

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  • From Snag@21:1/5 to Jim Wilkins on Mon Dec 12 12:40:12 2022
    On 12/12/2022 9:16 AM, Jim Wilkins wrote:
    "Jim Wilkins"  wrote in message news:tn77jp$27nid$1@dont-email.me...

      I'm going to have to take a minute to digest that ... OK , if I'm understanding this correctly I'll only have to cut one angle on the
    bottom , the other two will be produced by the way the hole for the
    collet is bored in the block - 2° tilt to the rear , 5° to the right .
    If I put a couple of degree angle on the left end I can set the fixture
    up to do the gash with the end mill horizontal/angled slightly down .
    Snag

    -------------
    I don't understand the last sentence.


    I was talking about cutting the end gash with the end mill held
    horizontal and using the edge of the grinding wheel . I've got this
    figured out now . I planned on making this with a screw lock and 12
    dimples in the collet sleeve to lock the setting . For now though it's
    on the back burner .

    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Jim Wilkins@21:1/5 to All on Tue Dec 13 09:31:12 2022
    "Snag" wrote in message news:tn7sid$29fcg$1@dont-email.me...

    I was talking about cutting the end gash with the end mill held
    horizontal and using the edge of the grinding wheel . I've got this
    figured out now . I planned on making this with a screw lock and 12
    dimples in the collet sleeve to lock the setting . For now though it's
    on the back burner .
    Snag

    --------------

    The screw lock style should be less demanding to machine, on mine the three spring-loaded balls have to all engage the dimples equally, but I can turn
    it with one hand that is on the far side of the fixture from the spinning wheel, and count the clicks. With the single screw lock a slight indexing
    error won't matter.

    Actually you need only as many dimples as you have flutes to sharpen, which
    for me is 8 on shell mills.

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  • From Snag@21:1/5 to Jim Wilkins on Tue Dec 13 11:53:04 2022
    On 12/13/2022 8:31 AM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tn7sid$29fcg$1@dont-email.me...

     I was talking about cutting the end gash with the end mill held
    horizontal and using the edge of the grinding wheel . I've got this
    figured out now . I planned on making this with a screw lock and 12
    dimples in the collet sleeve to lock the setting . For now though it's
    on the back burner .
    Snag

    --------------

    The screw lock style should be less demanding to machine, on mine the
    three spring-loaded balls have to all engage the dimples equally, but I
    can turn it with one hand that is on the far side of the fixture from
    the spinning wheel, and count the clicks. With the single screw lock a
    slight indexing error won't matter.

    Actually you need only as many dimples as you have flutes to sharpen,
    which for me is 8 on shell mills.


    I was thinking 12 since it's evenly divisible by both 3 and 4 and I
    have 3 and 4 flute end mills - and a rotary table (7.5 turns per 30° at
    90:1) . It's raining here again and I have no other projects ... except
    the neighbor's SxS UTV , and I ain't working on it in the rain . So a
    little while ago I started roughing stock for this project . Yesterday
    it wasn't raining , but I wanted to watch the guys installing my new
    septic tank . Concrete this time , the last one was steel and only
    lasted about 18-19 years .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Jim Wilkins@21:1/5 to All on Tue Dec 13 16:32:02 2022
    "Snag" wrote in message news:tnae60$2ij1f$1@dont-email.me...

    I was thinking 12 since it's evenly divisible by both 3 and 4 and I
    have 3 and 4 flute end mills - and a rotary table (7.5 turns per 30° at
    90:1) . It's raining here again and I have no other projects ... except
    the neighbor's SxS UTV , and I ain't working on it in the rain . So a
    little while ago I started roughing stock for this project . Yesterday
    it wasn't raining , but I wanted to watch the guys installing my new
    septic tank . Concrete this time , the last one was steel and only
    lasted about 18-19 years .
    Snag
    ---------------------

    Manual indexing is a tedious and error-prone task. You can double-check by setting dividers to the spacing of the first two holes and using them to confirm the next drilling location if you are interrupted. Any error should
    be large, a whole or half turn. My last dividing job was cutting a 68 tooth gear and there were issues... The one before that was 13, to spline a shaft
    for a motorcycle drive sprocket.

    That storm may be heavy snow or ice when it arrives here, 'tis the season. I finished prepping for it an hour ago.
    jsw

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  • From Snag@21:1/5 to Jim Wilkins on Tue Dec 13 17:07:14 2022
    On 12/13/2022 3:32 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tnae60$2ij1f$1@dont-email.me...

      I was thinking 12 since it's evenly divisible by both 3 and 4 and I
    have 3 and 4 flute end mills - and a rotary table (7.5 turns per 30° at 90:1)  . It's raining here again and I have no other projects ... except
    the neighbor's SxS UTV , and I ain't working on it in the rain . So a
    little while ago I started roughing stock for this project . Yesterday
    it wasn't raining , but I wanted to watch the guys installing my new
    septic tank . Concrete this time , the last one was steel and only
    lasted about 18-19 years .
    Snag
    ---------------------

    Manual indexing is a tedious and error-prone task. You can double-check
    by setting dividers to the spacing of the first two holes and using them
    to confirm the next drilling location if you are interrupted. Any error should be large, a whole or half turn. My last dividing job was cutting
    a 68 tooth gear and there were issues... The one before that was 13, to spline a shaft for a motorcycle drive sprocket.

    That storm may be heavy snow or ice when it arrives here, 'tis the
    season. I finished prepping for it an hour ago.
    jsw

    My table is still set up from cutting a pair of 58t 16dp gears for a
    rolling mill project a guy from the Logan Lathe list is doing . A dozen
    holes - well , dimples - is trifling compared to that . One of these
    days I'm going to pin that set of 37/47 (IIRC) metric transposing change
    gears I cut a while back . Haven't needed to cut metric threads yet so ...
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

    --- SoupGate-Win32 v1.05
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  • From Jim Wilkins@21:1/5 to All on Tue Dec 13 21:05:30 2022
    "Snag" wrote in message news:tnb0j2$2k0qo$1@dont-email.me...

    One of these
    days I'm going to pin that set of 37/47 (IIRC) metric transposing change
    gears I cut a while back . Haven't needed to cut metric threads yet so ...

    ------------------

    You would have needed them if you didn't make them.

    Shortly after buying the lathe I bought a metric transposing set of 127 and
    120 teeth, since 120 instead of 100 gave more of the fine metric threads I expected to need for the laser optics work I was doing then. Turns out the engineer decided to move on and take the idea with him. https://ieeexplore.ieee.org/document/9749702

    At the time the gears cost around $40 each. I finally decided to make a
    custom banjo stud to fit the double-keyed bushing that connects the gears, since its bore is smaller than the South Bend stud. The price of the
    standard 100 tooth gear is now up around $150 on Amazon, considerably more
    from the industrial dealers I called. Making your own was a good call. https://www.amazon.com/Boston-Gear-GB100A-Lightening-Pressure/dp/B004N62UIC

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  • From Snag@21:1/5 to Jim Wilkins on Tue Dec 13 22:15:28 2022
    On 12/13/2022 8:05 PM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tnb0j2$2k0qo$1@dont-email.me...

    One of these
    days I'm going to pin that set of 37/47 (IIRC) metric transposing change
     gears I cut a while back . Haven't needed to cut metric threads yet so
    ...

    ------------------

    You would have needed them if you didn't make them.

    Shortly after buying the lathe I bought a metric transposing set of 127
    and 120 teeth, since 120 instead of 100 gave more of the fine metric
    threads I expected to need for the laser optics work I was doing then.
    Turns out the engineer decided to move on and take the idea with him. https://ieeexplore.ieee.org/document/9749702

    At the time the gears cost around $40 each. I finally decided to make a custom banjo stud to fit the double-keyed bushing that connects the
    gears, since its bore is smaller than the South Bend stud. The price of
    the standard 100 tooth gear is now up around $150 on Amazon,
    considerably more from the industrial dealers I called. Making your own
    was a good call. https://www.amazon.com/Boston-Gear-GB100A-Lightening-Pressure/dp/B004N62UIC


    I got the RT shortly after I got the mill 'cuz I just knew ... turns
    out the first gears I made were to repair some 2:1 reduction pairs in
    the qcgb on my lathe . Those alone have saved me more than the cost of
    the RT and all the gear cutters I've got . Logan wants like 160 bucks
    for those little darlin's .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Jim Wilkins@21:1/5 to All on Wed Dec 14 07:19:09 2022
    "Snag" wrote in message news:tnbikt$2nsdj$1@dont-email.me...

    I got the RT shortly after I got the mill 'cuz I just knew ... turns
    out the first gears I made were to repair some 2:1 reduction pairs in
    the qcgb on my lathe . Those alone have saved me more than the cost of
    the RT and all the gear cutters I've got . Logan wants like 160 bucks
    for those little darlin's .
    Snag
    ----------------------------

    Did you make or buy the gear cutters?

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  • From Snag@21:1/5 to Jim Wilkins on Wed Dec 14 06:56:45 2022
    On 12/14/2022 6:19 AM, Jim Wilkins wrote:
    "Snag"  wrote in message news:tnbikt$2nsdj$1@dont-email.me...
      I got the RT shortly after I got the mill 'cuz I just knew ... turns
    out the first gears I made were to repair some 2:1 reduction pairs in
    the qcgb on my lathe . Those alone have saved me more than the cost of
    the RT and all the gear cutters I've got . Logan wants like 160 bucks
    for those little darlin's .
    Snag
    ----------------------------

    Did you make or buy the gear cutters?


    I bought mine . Ivan Law has instructions in his gear cutting book on
    making a device to make the gear cutters , I didn't want to build the
    apparatus . They average about 12 bucks each which I found reasonable .
    --
    Snag
    "You can lead a dummy to facts
    but you can't make him think."

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  • From Jim Wilkins@21:1/5 to Snag on Wed Dec 14 12:12:55 2022
    "Snag" wrote in message news:tnch6d$2pvve$1@dont-email.me...
    Jim Wilkins wrote:
    Did you make or buy the gear cutters?
    ...They average about 12 bucks each which I found reasonable .
    --------------
    I didn't look hard enough.

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