Steppers won't turn at low speeds

[rogerer]

I run a Gecko G540 along with 4 steppers from Keling (KL23H2100-35-4B) driven by the latest version of EMC2. Power supply 48 volts.

At low speeds/feeds the motors tend to stand still. I also use a cloned x-axis, sometimes at low feeds only one of the motors are turning. Anyone know that this i causing?

My config files are attached.

[mcphill]

Is this a problem running "in air", or built in to a machine? If in a machine, you may have too much friction in the drives and are not able to overcome it at lower speeds.

[rogerer]

They are running with no load, "in air".

[Big John T]

You might try here.

John

[Torchhead]

Make sure you have the proper current set resistors soldered to the connectors AND you have the Step Polarity set right in EMC. It has to be POS pulses. That means with no pulses the Step signal is LOW and the (short) duration pulses go from low to high into the G540. The motors may spin with the wrong polarity but stall way too early and may exhibit other problems.

TOM Caudle
www.CandCNC.com
Totally Modular CNC Electronics

[rogerer]

Originally Posted by Torchhead Make sure you have the proper current set resistors soldered to the connectors AND you have the Step Polarity set right in EMC. It has to be POS pulses. That means with no pulses the Step signal is LOW and the (short) duration pulses go from low to high into the G540. The motors may spin with the wrong polarity but stall way too early and may exhibit other problems. TOM Caudle www.CandCNC.com Totally Modular CNC Electronics

Current set resistors - check
Step polarity - Where do I check this?

[Torchhead]

That is an EMC question for which I have no answer (I use MACH3). We have a lot of experience with all Gecko products but all our interface controls are based on MACH and the Profiles (XML's) we send with the G250 (drive used in the G540) based products are setup with the correct output polarity.

TOM Caudle
www.CandCNC.com

[BMG]

Torchhead

You should head to the EMC IRC channel. There should be any number of people there that can either help you outright or point you in the proper direction. Head to the LinuxCNC.org site - follow the "GET HELP HERE" link and use the link to log into IRC right from the website. Once in - simply type in your questions providing some hardware and machine configurations. Then sit back and usually it will get a reply within several minutes if not right away. Plenty of active users and developers are always lurking.

HTH's