Re: re:Material to use for ballscrew mounting

Ballendo:

Where may a machinists or design guide be located that has standard
hole diameter callouts for various classes of fit? I.e., to be used
in a detail drawing callout?

Thanks, Ron

--- In CAD_CAM_EDM_DRO@egroups.com, ballendo@y... wrote:
> Wally,
>
> snips/answers below
>
> >One of the things that has not been talked about is
> >materials used for construction of the bearing mounts.
>
> >1) I think an aluminum bearing block would be ok. But what about
> >the end caps if using a rigid mount. Would the bearing faces
press
> >or work there way into the soft aluminum over time.
>
> If the tolerances allow the movement, or "working" of the bearings,
> THAT is your problem, not the material, IMO.
>
> >2) If spacers are used in a rigid mount could they be aluminum or
> >should they be steel.
>
> Since we're dealing with thermal properties here, I'd use something
> close to the material of the screw. So; steel.
>
>
> >Also have a few general construction questions.
>
> >1) If 2 angular contact bearings are used for rigid mount with
> >spacers of the same dimension on both inner and outer races. Do
you
> >have to worry about preload or do you just tighten the nut on the
> >leadscrew shaft a couple of grunts.
>
> I like your "torque units" :-) . IF the spacers(relationship) size
is
> correct, then a "grunt" or two should not matter. Be aware of
> the "grunt" ratio (housing grunts vs. leadscrew grunts).
>
>
> >2) What about the bore diameter for you bearings. It seems you
> >want the bearings to move as you tighten your end plate or if you
> >add shims but you would not want the outer race to spin in it
> >housing. What type of clearance/press fit should be used.
>
> Light press fit. A little more than you can do by hand, but pretty
> easily done with a small arbor press, IMO. You didn't mention this,
> but same holds for the leadscrew diameter/bearing fit.
>
> Hope this helps.
>
> Ballendo