Hello,

I'm building a machine with an external footprint of about 1500mm x1000mm (see picture). I was reading up about ballscrews and the factors that should go into making a decision. It seemed to me that the biggest factor was ballscrew whip.
My plans for the machine are mainly based around aluminum machining and engraving and thus chose 5mm lead as it is reputed to give better resolution/torque.
Next I started considering ballscrew diameter and after looking at a few charts found on the web came up with a critical speed of about 1100-1300rpm when considering a 20 or 25 mm ballscrew.

I'm not totally decided on my drive system yet, but will most likely run a g540 w/ some larger steppers (recommended specs anyone?)

What are the disadvantages/advantages of going with 20 vs 25mm ballscrews?

Thanks in advance!