Re: Ball screw adjustment?

Allan:

There are usually two types of ballscrews, rolled & ground. The rolled
are 3 or 4 thousands/ft and the ground have much better tolerance. The
ground are also much more expensive. They usually also have precision or
selected rolled threads. I think they make the screws and then select
the best precision for these. They are better than general rolled
threads but far from ground, in both precision and cost.

That price of $411 may be for a ground nut/screw. I just got a quote
from Rockford for a .615" rolled thread anti-backlash nut of $123. A
similar anti-backlash nut for a .770" thread was $174.50. The "accurate"
rolled screws were $16.50 and $32.50 per foot respectfully.

I think for hobby applications the rolled screws are fine. For my stuff
the ground ballscrews would be a miss-match.

The sticker shock may not be as bad as you think. :-)

On 5 Nov, allan_r9@... wrote:
> I talked to Rockford today, and they quoted $411.50 for the 3/4"
> preloaded nut for the precision screw, which gave me pause. I'm
> looking for other options before buying 3 of these plus the screw
> material!
>