Quote:
Originally Posted by Chris Fultz
And if you decide to use COTS gears (lots of good sources), a good general guide for gear spacing is (1/2)PD1 + 1/2(PD2) + .006. (in inches).
PD1 is Pitch Diameter of Gear 1, PD2 is Pitch Diameter of Gear 2.
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I know the additional .006" is some fudge factor, effectively trading gear life for less friction in operation. But the number I'd learned from oral tradition* is .003" or so. What are the benefits of adding the extra distance?
*Even before I learned this from other FIRSTers, I knew a variation on this from racing R/C vehicles, which have a similar opinion of gear life vs. speed**; there, the conventional wisdom is to run a piece of paper between your pinion and spur gears to ensure "proper" spacing--and a piece of paper is about .002" thick.
**If you haven't gathered from the "racing" part, they skew towards speed.