# formula for shimming D shaft?

I've just started playing with quadcopters, these are really neat toys.
One variety of cheap ones drive a moulded plastic prop (x4) with a d.
These are all loose about the same amount. I can easily measure how loose by angle.
Is there a formula to calculate the shim from the angle?
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Not a reliable one. You'd need to know the depth of the flat for both the shaft and the recess to work it out by triganometry, and any rounding of the edges of the flat would cause significant error.
--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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Agreed. Things to try to shimming what I assumed to be small diameter shafting on plastic would be plain string, or even pieces of rubber band. They both have enough give and cost nothing and keep things simple.
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On 11/17/2015 4:14 AM, unk wrote:

Little bit of silicone caulk.
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On Tue, 17 Nov 2015 20:46:40 -0500, Steve Walker wrote:

Thanks guys.
You have to be able to remove props, so something like a silicone that will release from the steel and nylon-ish plastic could be good enough, just scrape it off and squirt some more in.
The issue is that the thing is jittery and I suspect it's the props wobbling between driven and driving. What's the hardest when set type of silicone you can get in a small tube? Bonus points if it cures fast.
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wrote:

May not be helpful to your application, but silicone can be thinned with acetone and painted on. Still sets and seems just as strong. Think it was type 1 that worked better, the one that has that has the strong odor.
--
William

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I've never had good luck with silicone as any type of shaft lock or material to keep shafts and collars tight. It just has no strength, and doesn't bond all that good to things like shafts anyways, plus it adds no pressure to keep whatever on the shaft tight.

RTV gasket silicone has fillers and dries fast, but again, it's a poor material for this type of use.
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Shoe Goo ought to work just fine.
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
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On 11/18/2015 6:29 AM, unk wrote:

Probably a little loose on purpose, to keep vibration from spreading, OR, maybe so the prop and shaft will beat themselves to pieces. Planned obsolescence. I would use softer silicone, to absorb the vibration. Make sure the prop and shaft are perpendicular to each other while drying.