Duel Lead Screws

[bb99]

Hi All,

I'm in the process of designing my first CNC router table. The design that I'm thinking of will require a gantry span of 5'. I figure that my light-weight gantry design will not be stiff enough to be driven by just a lead screw on one side. I thought of placing a crossbeam underneath the table connecting the two legs of the gantry. However, I've decided not to go in that direction. Instead, I'd like to have a lead screw on each leg. Has anyone driven a single axis using two lead screws before? If so, how did you drive the screws (two motors)?

Thanks,
bb99

[ljoe1969]

shopbot uses 2 motors on the x - axis. and rack and pinion istead of lead screws.

a friend of mine has one.

[balsaman]

You could go with two screws, one motor, two pulleys and a belt.

Eric

[CAMmando]

following up with Balsaman, check this thread

http://www.cnczone.com/showthread.php?threadid=1355

CAM

[bb99]

Greate ideas! This will give me lots to think about.

--bb99

[solarchimesam]

BB99,
I run a twin steppers on X with one controller, its a low cost K179 driver.
screws on left and right side and works real good. You have to get the
steppers wired right. I could email you the wiring.

As a matter of fact if I turn stepper 1 by hand with power off, it will make stepper 2
turn...acts a brushless DC motor. With power on they are in perfect sync and push my heavy router and carriage with no troubles. I just increased the volts to the stepper controller + wire to make up for the extra current draw.
Best of luck!

[bobleecnc]

high this link doesn't work anymore can someone post the correct one? thanks.... Bob

http://www.cnczone.com/showthread.php?threadid=1355