Use this link.

http://www.nookindustries.com/ball/BallCalculators.cfm

use the root diameter that is normally about 2-3 mm lower than the outside diameter and select the mounting type you are using, and it will calculate the max speed before it will whip.
If you have any question, or need help give me a ring on monday.

Gary

Quote Originally Posted by tribbles View Post
I used 25mm OD ballscrew with a 25mm pitch for mine, and with the motors I've got, I get 18m/min, which for about a 1.4m run gives ~4.7 seconds for total travel. However, you will need to worry about whip.

Gary (from Zapp) gave me a website which allows you to calculate the whip speed based on the diameter and so forth - unfortunately, I've only got the link at work, but Gary may come on here before I get the chance on Monday to get it.