RE: [CAD_CAM_EDM_DRO] Re: fitting ballscrew ends

Marcus,

I also find machining ballscrew ends not really a big deal. I do
use an offhand grinder to remove most of the hardened land material
though...saves a bit of time and helps prevent interrupted cutting
with the carbide tool.

I think part of the issue is the tools available. Perhaps many hobbyists
do not have lathes with large enough bores to accommodate the screw,
or they do not have enough rigidity. We don't have that problem...but
we are not hobbyists.

Here's a thought:

What if there was a pre-machined ballscrew end that just screwed on to
the unmachined ballscrew end? Internal threads would engage the screw
ball race area rather than the sometimes non concentric lands.

It would have to be pinned (taper pin) but a pre-drilled hole could
facilitate
making the hole. Perhaps some rough offhand ground "flats" in that area on
the
screw would allow the use of ordinary drilling and reaming methods.

I could make such a product...but I have not considered how much it would
cost.
The logistics of having to have many different models for different screws
is an issue. The threads would not have to be exactly the same profile
though...
just something that engaged a particular pitch and minor diameter in an
angular
contact fashion.

What do you think?

Les

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

Main page:
http://www.lmwatts.com
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http://www.lmwatts.com/shop.html
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-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com]On Behalf Of Marcus and Eva
Sent: Friday, June 10, 2005 1:02 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Re: fitting ballscrew ends


Hi John:
Aren't you concerned about splitting the end of the ballscrew if you try
to press fit a stub in to the end?
It's a case hardened screw, and the small root diameter is not going to give
you a lot of meat for a decent sized stub.
Even in a best case, you'll bulge the end of the screw and make the last bit
unuseable to drive the ballnut on.
That's probably not the end of the earth if you plan your design so you
can't run the ballnut over it inadvertently but you do have to be aware of
the problem and design accordingly.
All this seems an awful lot of farting about, to avoid what really is still
a pretty simple task.