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View Full Version : Newbie How many Steps/rev.(for 1.8°motor)?



submarineboat
02-18-2009, 12:50 PM
Greetings

I have my table; an old DynaCNC 5x10 up and tuned with it's Keling KL-11078 drivers under Mach3. I set the drivers at 2000 Steps/rev just because that was a number I saw someone else using. :) Both the X and Y axis in Mach3 are set to 1874 steps. There is a belt reduction on the motors so I just measured and changed the setting. I did not calculate the reduction.

The speed looks good to me now. Routing may take a while, but it's plenty fast for the plasma cutting I plan to do. And it's accurate to at least 1/16" over 8 feet which is much better than I need.

The details are on this page: www.submarineboat.com/plasma_router_cnc.htm

So is 2000 Steps really a good setting? Is it correct that the top speed will
higher but the accuracy lower if I set steps to a lower value?

Thanks
Doug

Crevice Reamer
02-18-2009, 01:44 PM
Hi Doug.

Zero the Mach DROs. Call for an axis movement of say 6 inche on each axis. Measure the actual distance traveled. If actual travel distance matches Mach DRO indicated travel, then steps are set correctly. If travel does NOT match DRO, then you must add or remove SPI.

For Accuracy, You MUST have steps set correctly. There is no adjustment for speed.

I think maybe you are thinking of MICRO STEPS setting on drive. Full step may run fastest, max microsteps may run the slowest.

CR.

H.O
02-18-2009, 01:48 PM
Hi Doug,
Yes, if you lower the resolution you get higher speed at the same step-frequency. That is, if you have Mach3 (or whatever you use) set to 25kHz and you're maxed out in motortuning and then change the drives to 1000 steps/rev you'll get double the speed but half the amounts of steps/unit of movement. This resolution/accuracy thing is only valid to a certain degree. Just because you set the resolution of the drive to 10,000 steps/rev (if that's possible on your drive) doesn't mean that the motor will position to within 0.036°.

I'd say 2000 steps/rev is a good place to be if you get the speed you need. Increasing the resolution on the drive probably won't give you much better accuracy so if you need/want better resolution/accuracy it's probably better to increase the reduction ratio between the motor and drive elemet (screw, belt etc).

HTH
/Henrik.

submarineboat
02-22-2009, 01:12 PM
Thank you. I appreciate the feedback, it is most helpful knowing I can increase the speed if needed.

Best of Luck
Doug
www.submarineboat.com