Ignoramus25214 wrote:
I went to an auction recently and picked up a set of screws that
turned out to be ball screws for a 9x42 Bridgeport.

http://igor.chudov.com/tmp/Bridgeport-Ball-Screws/

I am a little surprised about it, as, I thought, ball screws could
only be used in CNC mills whose screws were held by stepper
motors.

So, do they have use in a manual mill and are they in any way better
than regular drive screws? Or are they for CNC conversion only?

Unless I'm mistaken , the big advantage to ballscrews is that they have
virtually zero backlash . I don't know any reason they can't be used in a
manual mill .
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On 2008-12-20, Terry Coombs wrote:
Ignoramus25214 wrote:
I went to an auction recently and picked up a set of screws that
turned out to be ball screws for a 9x42 Bridgeport.

http://igor.chudov.com/tmp/Bridgeport-Ball-Screws/

I am a little surprised about it, as, I thought, ball screws could
only be used in CNC mills whose screws were held by stepper
motors.

So, do they have use in a manual mill and are they in any way better
than regular drive screws? Or are they for CNC conversion only?

Unless I'm mistaken , the big advantage to ballscrews is that they have
virtually zero backlash . I don't know any reason they can't be used in a
manual mill .

I thought that the problem with ballscrews is that they can start
rotating under pressure. So if you do, say, a climb cut, the endmill
can pull the table towards the endmill.
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On Dec 20, 7:53*am, Ignoramus25214 ignoramus25...@NOSPAM.
25214.invalid wrote:
On 2008-12-20, Terry Coombs wrote:



Ignoramus25214 wrote:
I went to an auction recently and picked up a set of screws that
turned out to be ball screws for a 9x42 Bridgeport.

* * *http://igor.chudov.com/tmp/Bridgeport-Ball-Screws/

I am a little surprised about it, as, I thought, ball screws could
only be used in CNC mills whose screws were held by stepper
motors.

So, do they have use in a manual mill and are they in any way better
than regular drive screws? Or are they for CNC conversion only?

* Unless I'm mistaken , the big advantage to ballscrews is that they have
virtually zero backlash . I don't know any reason they can't be used in a
manual mill .

I thought that the problem with ballscrews is that they can start
rotating under pressure. So if you do, say, a climb cut, the endmill
can pull the table towards the endmill.
--
* *Due to extreme spam originating from Google Groups, and their inattention
* * * to spammers, I and many others block all articles originating
* * * *from Google Groups. If you want your postings to be seen by
* * * * *more readers you will need to find a different means of
* * * * * * * * * * * *posting on Usenet.
* * * * * * * * * *http://improve-usenet.org/

Yes, ball screws do not provide much resistance. If you mistakenly
leave the Y axis lock loose, (when moving the X), it can move the Y.
Climb milling is also a problem.

Ball screws have been retrofitted on machines that were primarily used
for precision boring many holes on long parts. The ball screws can
have better tolerance over long lengths, and are less prone to wear
(when properly lubricated).