Re: [ATM] How to Reduce Bearing Friction

[Mark Holm <mdholm@telerama.com>]

hermit wrote:
> I think there was some criticism when this came out about whether or not
> the modeling really was applicable to what we do.  Is this the one with
> inclined planes?

No, as I recall, he had a "sled" with feet of Teflon or other plastics
sliding on flat surfaces of Ebony Star, or other surface materials.  I
recall that he also had static, or starting friction as well as curves
of friction vs. speed for a range of speeds applicable to the Dobsonian
application.

> A simple scale will let you measure forces that you
> need to push or pull your own dob around.

Yes, but it is the static to dynamic ratio and the shape of the early
part of the friction vs. speed (dynamic) curve that is important for
smooth motion.  This can only be got by controlling speed add you
measure force.

Actually I suggest you dig up the article, because there is a fair
amount of "meat" there: well thought out and well presented, relevant
experiments.

-- 
Mark Holm
mdholm@telerama.com

_______________________________________________
ATM mailing list http://www.atmlist.net/