SPEED! New Drivers or Different Leadscrews?

[leeleatherwood]

Ok, I am building this CNC Plasma cutter. Its running a Hobby CNC 4AUPC rev2 driver, Hobby CNC 305oz Motors and 1/2-10 single start leadscrews and a 36v power supply. It has dual motors for the Y-Axis, gantry weighs about 30lbs.

I am only able to get about 60-70ipm rapids before the motors lock up, I am also getting an annoying mid-band resonance at around ~30ipm that sounds horrible but does not cause any lost steps that i can detect.

My machine is a 4x4 so 60ipm is very annoying, and I also need high speed for the plasma cutting operation of sheet metal.

I am unsure what to upgrade. While using a 24v power supply I can only attain about 40ipm, with 36v that jumps up to about 70ipm. This leads me to believe that some Gecko G201X's will solve my problems by allowing me to run 80v to the motors, this will also allow me eliminate mid-band resonance. BUT I may run into leadscrew whip, on the other hand my leadscrews are supported on both ends.

My other option I see is to switch to 5 or 10 start leadscrews. Since I would need to replace all my Ant-Backlash nuts, Couplings and 12ft worth of leadscrews, this comes close to the price of 4 new G201X's. Would allow me to run slower RPM's, while the torque increase would be nice I dont think I need it since a Plasma machine has no "load" like a router. But this would keep down on the leadscrew whip.

Thanks!

[ger21]

Depending on how fast you want to go, you may have to replace the screws either way, due to whip. My 60" 1/2-8 2 start is only good to about 160ipm before the whipping gets too severe.

[James Newton]

What is the current rating on the motors and how many amps can the drivers put out? How many wires on the motors?

[adel_sebaey1]

Good I hve the same idea to do.

[leeleatherwood]

Sorry for the late reply.

#23-305-DS8A 425oz-in bipolar rating, 305oz-unipolar rating, 4.2v, 3A, 200 S/R, 3.2mH, Size #23, Dual Shaft, 8 wire

3 or 4 Axis Unipolar Chopper control.
Individual OR simultaneous control of 2/4 Phase Stepper Motors.
Accepts 5, 6, or 8 wire stepper motors only. 4 wire types are not usable.
42VDC maximum input voltage, 12VDC minimum input voltage. 24VDC Minimum Recommended Voltage.
3.0 Amps Maximum per Phase, 500ma (.5A) minimum. Each axis adjustable throughout this range.
1/1, 1/2, 1/4, 1/8, and 1/16 Microstepping.

Notice is says max 42VDC for the controller, but after doing research it seems the max safe voltage is between 38-40vdc, nobody makes a power supply in this range so you have to run at 36v.

[leeleatherwood]

Originally Posted by ger21 Depending on how fast you want to go, you may have to replace the screws either way, due to whip. My 60" 1/2-8 2 start is only good to about 160ipm before the whipping gets too severe.

Yeah i am currently looking into Rack and Pinion.

[vger]

You might take a look at this thread if you haven't already...

http://www.cnczone.com/forums/linear...e_ever_if.html

Steve