Spinning nuts!

[turmite]

"How are the spinner nuts different than fixed? Are there major differences in tolerence, size of balls...? I have two 1.125"/.200 pitch, anti-backlash double nut screw setups that could save me some serious money when I get to buil my machine if I can get the spped I need by spinning the nuts and fixing the screw. Whit that said I need 300 ipm as a max using the .200 nut and I need to push something in the 200-275 lb range. The machine itself will be a heavy frame and will be using linear ways such as Thk etc."

I posted this question in the clubhouse forum several days ago and still have not gotton a response so I figured I would try it here. This is in response to a Thread that asks why we spin the screw?

Any help?

Mike

[lsfoils]

Hi Mike,

According to the Roton catalog, if your minor diameter is 1.0" and you want to spin @ 1500 rpm (300ipm with a .2" pitch) you will have a limitation of about 65" in length. I couldn't find any reference on this chart regarding load. That information is for turning the screw. They don't mention or list a spinning ball nut. I purchase a ground ball screw on ebay that had the the ball return buried within the nut housing. This would make it somewhat more balanced than the ones I'm spinning on my Z. I'm not turning my Z all that fast. Heres a pic. When I purchased it I had figured on turning the nut.

Doug