Leadscrew resonance

[davidmb]

I guess I already know the answer but thought I would ask anyway.

I am building a 1m x 550mm cnc router and have now realised that the 1m x M12 leadscrew that I'm using for the major axis sets up a resonance at the high traverse speed, this vibration makes it self felt on the gantry. At cutting feed rates this does not occur, any suggestions?

( I guess I could go to a M16 or M20 leadscrew for increased stiffnes, or a 4-5mm lead rolled leadscrew for lower rotational speeds )

[jeffs555]

You didn't say what the pitch of your screws was or the speeds you are trying to obtain, but you can go to this page where they have calculators for maximum speeds of metric and inch lead screws. http://www.nookindustries.com/acme/AcmeHome.cfm
A lot depends on the bearings, so if you currently have simple end bearings on your screws, you might be able to improve things with better end bearings.

[davidmb]

Hi, thanks for the link.

I can get 580 rpm out of the motors without stalling or missing steps, the lead is 1.75mm giving 40ipm, once I have proved the machine then I will likely upgrade these to 5mm lead rolled thread leadscrews. The y & z axis use M10x1.5, these work fine but are of course much shorter.

The end bearings are angular contact bearings with a little bit of preload.