Go to this page:


https://www.zappautomation.co.uk/ecalculators.html

Click on 'Critical Speed Calculator' in blue at the bottom.

That tells you how fast the screws can go before whipping. You didn't say how long they are so or how they're supported so I can't go and find that for you :P

Thats the big limit on maximum rapid speed - what is of more interest is if you can accelerate up to a max rapid speed in a reasonable distance, but thats a far more complex question. On this forum is a motor calculation spreadsheet which will answer your question, but you'll need to provide it with a lot more information. Look at the thread below for the spreadsheet and discussion on how to use it. Page 3 of my build log details the calculations for my build which sounds similar to your setup.

http://www.mycncuk.com/threads/1524-...otor-do-I-need

Now, having said all that, assuming a typical design and weight of gantry ~50kg, you should be able to reach 5m/min rapids without any issues.