[chazw44]

I am thinking of adding a 4th axis on my homemade cnc machine to turn my workpiece radially. My controller only has 3 ports. I'm wondering if I can disconnect either my x or y axis stepper motor from the controller and then use that free port to run a spare motor which will be set up in the mach 3 sw using the A axis. Since the A axis will turn the workpiece radially, I only need to move the router on the Z axis and in one other direction...either X or Y. Wondering if anyone has successful tried doing this.

[aarggh]

That's exactly how a lot of the Chinese CNC machines are configured, usually the X axis is moved to the rotary axis. On my 6090 this is how it's configured so the rotary axis is placed longways along the Y Axis and the X controls the rotary moves.

cheers, Ian

[chazw44]

Thanks Ian

I'll go on the assumption then that my idea will work for my setup. I'll get myself a spare stepper motor and go from there

Charlie

[aarggh]

If you do that, it's important to match the rotary stepper to the X or Y axis your connecting it to, otherwise you'll need to reconfigure the stepper settings everytime you use it. It's a little thing, but it can get annoying, especially as you'll likely need to calibrate each time too then.

cheers, Ian

[awerby]

If you do this, remember that you'll have to provide a brake of some kind for the axis that isn't being used, since the stepper won't be energized and keeping the axis from back-driving itself out of position.