How fast can you spin Acme thread?

[Ed_R]

I'm really wondering how fast a piece of 1/2-10 SS Acme Thread thirty-six inches long can spin before it goes wacky? I mean, THsi stuff is 10 Turns Per Inch, so 1000 RPM on the thread moves the carriage 100 IPM, right? So if there's no serious binding problems on terh end bearings, and ther's a single nut pushig the carriage, and the cariage is suppoerted on both sides by steel bars running through bronze bushings, how fast do you think you could turn the thread before it goes all sinewave?

[ger21]

Depending on how it's mounted, anywhere from about 50 to 200 ipm, or 500 to 2000 rpm, based on the critical speed charts at Nook. http://www.nookind.com/acme/AcmeCharts.cfm

While your there, read up on the mounting types to understand the chart better.

[Ed_R]

Looks like I'm headed for around 90 IPM with 1/2-10 thread. I'm not sure I understand mounting type D at all but mounting type C is the closest to what I'm using, expect mine is single-bearing on each side. DAng. I'm not sure I'm getting things right here. Aren't all these other poeple running acme 1/2-10 and getting much faster rates?

[Halfnutz]

I have one spinning at 2800RPM 40 inches long, but thats really pushing it. It is enclosed also, and I hear it vibrating slightly. I have no idea what the reccomended limits on it are, but I think probably less than what I'm doing with it.

[ger21]

I'd guess you closer to type B. With type D, the screw doesn't spin, the nut does. the screw is locked in place.

Actually, 100-125ipm is about as fast as I've seen with 1/2-10. You also become limited by the speed of your steppers.

[ViperTX]

The other thing to consider when using the 1/2 inch stuff...is the bearing journal size and the size of the journal to couple the stepper/servo to.

I used 3/4inch and had to use metric sized journals to get it all to work.

[Ed_R]

I knew I wasn't a D, I saw the nut was the moving piece there. Interesting design idea but not applicable to my particular hardware

Originally Posted by ger21 I'd guess you closer to type B. With type D, the screw doesn't spin, the nut does. the screw is locked in place. Actually, 100-125ipm is about as fast as I've seen with 1/2-10. You also become limited by the speed of your steppers.