Re: [CAD_CAM_EDM_DRO] Silly machinist... Was: Accuracy and heat was Re: re: Re: New file upld to CCED

> ROTFLMAO!

:-).

> Even making both parts to the exact same size diameter creates
> assembly problems...unlees your planning on heating the
> external part for assembly to a shrink fit.

They were meant to be a press fit, as the parts were for reduction boxes on
powerful brushless motors. But not as much of a press fit as I got.. The
hole I was aiming for was dimensioned at 20.01mm, which was what the
supplier of the bearings suggested as a starting point.

On a slightly different tack I've just been playing with internal clearances
with an eye to my lead screws when I do them.... With a 12mm ID bearing.
With an alloy shaft I can press 12.05 easily (universal tapping device used)
but for SS rod anything over 12.00 is impossible, or as good as I can
measure anyway. (must get a better micrometer...).

For us non-machinists on the list, what are the normal clearances for
fitting bearings? I've always worked on about 0.02mm interfearance for
alloy on the inners, and spec'd dimension for the outer. Bearing in mind
that I'm a computer and electronics engineer, and all of my machining skill
comes from fiddling around, guess work and reading. Every now and then I
visit a friend who runs a precision engieering shop if I get really stuck,
or stuff the tool into the chunk and need a new toolpost machined :-).

Cheers, Chris.

* Design engineer, Assembly worker, Cleaner.
* Ohmark Electronics. PO Box 5302, Christchurch, New Zealand.
* http://www.ohmark.co.nz