Rack n' Pinions take the stress?

[norby16]

Hey guys,
I'm in the middle of getting parts in to build my first cnc router, so I have no clue if something should sometimes be the way it is... Some thk linear slides came in for my Y axis yesterday. They slide pretty smooth as far as I'm concerned. What I'm wondering about is what will be responsible for keeping the router in place while operating on the Y axis. The rails obviously don't so is all the stress on the stepper motor? Heres a few pics to demonstrate what I'm talking about. ( BTW not my pics, some I found on google )


By norby16 at 2008-12-05

Is the rack the only thing responsible for holding the axis position? Maybe once my nema 34 1200 oz motor comes in it will answer my own question...

Heres another design I found;

By norby16, shot with DMC-FZ20 at 2008-12-05

Kinda like the Z axis screw this one runs along the entire length of the axis.

By the way the router is gonna be a 5 x 9 so from what I've gathered the "screw" drive designs are only used on the smaller routers...

On another topic, would you recommend using the same rails as pictured above for the long X axis? Haven't seen it done but it seems to me like a good idea...

Thanks for reading!

[ger21]

Yes, the rack and pinion is responsible for positioning.