RE: [CAD_CAM_EDM_DRO] My ballscrew / bearing block design.

Yes...if the preload tolerance of "light" in your particular case goes
all the way to zero I would use medium. More typically light means
5%...that can be a couple hundred pounds. I notced Dave's link to
VXB mentioning their max dynamic and static loads. Those values may
be correct for that bearing...but typically a 7202 is a couple
thousand pounds radial...with axial perhaps being as much depending on
the contact angle.

Yes even shrink fits can slip...pin it.

Just typical polishing methods will be fine for seals. Unhardened
steel will work (i use it), but of course hardened is better. Speedi sleeves
are fine.
Many of the seals with spring garters create a bunch of friction though.
You can remove the garter springs and have someting better than
just a shield but still with low friction.

Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

Main page:
http://www.lmwatts.com
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-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com]On Behalf Of fj62@...
Sent: Monday, November 07, 2005 10:40 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: RE: [CAD_CAM_EDM_DRO] My ballscrew / bearing block design.


A couple more questions...

I picked medium preload because light went from 0 to X lbs of preload. I
wasn't sure that would guarantee no backlash. Will a light preload
generate a no backlash setup?

I'm sure I learned about shrink fits at some point in my machine design
class but that was 15 year ago...If I shrink fit a piece on the ballscrew
and then machine it will it "loose its grip and slip" (obscure reference
to 'you ain't got a hold on me' - AC/DC)?

Is there a technique for getting the required surface finish for the
seals? I was also wondering about the hardness required for them. I was
contemplating just putting speedi-sleeves on these portions of the shaft.

Thanks,
M