• "Lippsing" a Q-tip propeller

    From rnadms@gmail.com@21:1/5 to All on Fri Oct 20 15:17:42 2017
    On Thursday, April 16, 2009 at 6:38:17 AM UTC, MP wrote:
    Thought I'd ask for comments before doing something stupid and irreparable
    to our propeller.

    We have a Hartzell Q-tip prop on our Glasair. That's the fancy bent over tip that gets all the jokes about the FAA Inspector who grounded a Cheyenne when the propellor first came out. (Looks like the prop had a ground strike.)
    When we got it, the Q-tip was a hot thing, and we were coming off a Prince P-tip, which also had a turned under "winglet."

    Then Paul Lipps came along and wrote that putting a big hunk of metal out there on the prop tip is about the stupidest thing one could do, since the prop tip is where velocity - and therefore, drag - is highest. He wrote
    about cutting the tips off a Prince wood prop and getting a phenomenal improvement in propeller efficiency.

    I'm not going to cut off the Q-tip entirely. But I thought I would try a compromise solution, and cut part of it off. I should link a photo to show you my markups on the tip, but the plan is to cut the front of the winglet
    to put a 60 degree shear on the front, like you see on the Katana wingtips and on Paul Lipps' Lancair. I will be careful, will sand out the stress risers, etc. I have a good gram scale to weigh the cutoffs to match, and a dynamic prop balancer to rebalance after the operation.

    It's a homebuilt, so I'm deep into "experimental" mode on this one. Anyone want to warn me about how I might kill myself doing this? Has anyone done this before?


    Mike Palmer <><

    so how did it work?

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