[leversole]

Planing the upgrades to my CNC Router...

I will use 15mm linear rails and 16mm ballscrews...for creating space for the ball screw (between the stationary and movable part), does it make any difference whether you put your spacer under the trucks or the rail?

For example, on my Z axis the back plate will be stationary and have the rails bolted to it, the router mount will have the trucks mounted to it, I need to create space to put a 16mm ballscrew between them, I was going to mount the rails to the plate, and space on the trucks, as I can make some reasonably flat spacers for the trucks on my mill.

Am I on the right track? Opinions? Thoughts?

Thanks

[dmalicky]

Spacers can go under either -- the key is they need to be really stiff and well-bolted, but they're probably not needed if the design is changed. Most people use 20mm rails because 15mm rails have tiny bolts, and 20mm gives room for the ballscrew. Often the nut flange sits in a cut-away in the plate or the nut is mounting at the top of the plate. Then the nut flange can overlap the plate.

[leversole]

Thanks!