Replacing a Tormach 3-Phase stepper driver with a Leadshine driver

[Titanium]

I’ve been helping a local high school where they have a 24R CNC router that has a bad Z-axis stepper motor driver (Tormach 32000/ Leadshine 3ND883). While waiting for the schools purchasing department to get a replacement Tormach driver, I went ahead and bought a Leadshine 3DM883 as a temporary replacement to get them back in business a little sooner.

Tormach’s 32000 driver uses a 10-pin (5x2) IDC flat ribbon connector for the step and direction signals whereas both the Leadshine 3ND883 and the Leadshine 3DM883 both use the standard Phoenix-style connectors.





Unfortunately the Tormach IDC pins and the Leadshine Phoenix pins don't have simple one-to-one relationship. I found this very useful thread that helped a lot on the pin relationships. I traced the 10-pin IDC connections on the Tormach 32000 and confirmed that the pins matched the picture below, I.e. only pins 3,4 and 5 of the ribbon cable were being used.

https://www.cnczone.com/forums/torma...r-pinouts.html








The last two pictures show how I converted the Tormach female IDC connector to the Phoenix-style connectors on the drive.

After installing the temporary Leadshine 3DM883 and the modified signal wires, I am unable to get any movement on the Z-axis motor. I confirmed that there is 69 Volts DC between the VDC and GND pins at the driver.

In an effort to troubleshoot, I tried to find the +5 Volt on ribbon pin 3 by disconnecting the ribbon cable from the drive, but I got confusing readings of 0 VDC and about 24 VAC on all the pins 1 through 6. I was even getting readings of 3.3 VAC on the unused pin 6 through 10. These readings were taken at the female 10-pin IDC connector going back to the Tormach control board. I’m not even sure what the pin 3 signal level voltage is supposed to be, or even whether it is AC or DC?

Any ideas or suggestions?

 

[markba633csi]

Check that you are not missing a ground or something simple like that
You should be getting steady readings for the power pins
The direction signal is either a high or a low but the step signal is a pulse, you'd need a logic probe or scope to see it

 

[Titanium]

Mark, thank you for your help.

All of those voltage readings were just on the control signals on the 10 pin female ribbon connector coming from the ECM1V1.5 control board. I was sticking a short breadboard wire in the 10 pin female connector and then using a multimeter to read voltages between that wire and the aluminum backplane where all of the electrical components were mounted. The power pins had a steady 69 VDC.

It sounds like it would be possible to see the direction signal voltage with my multimeter, but not the step signal. I found out that the control voltage from the control board to the stepper driver is 5V. I will need to be sure that the 3DM883 jumper is set to 5V and not to 24V.

After poring over the 3ND883 and 3DM883 manuals for what seems like the tenth time, I discovered a difference between the two drives on the Dynamic Current dipswitch settings SW1, SW2, and SW3. The existing 3ND883 had ON-OFF-ON which translates to 6.6 A peak/4.7 A rms. I had the new 3DM883 set to the same ON-OFF-ON, but discovered tonight that those settings are actually 3.9 A peak/2.8 A rms. The 3DM883 requires OFF-ON-OFF to get the same Dynamic Current setting as the old drive.

I was surprised to read in the manual that "DIP switch current setting is wrong" is listed as a possible cause of "Motor is not rotating"?!? I would not have guessed that a wrong current setting could have that effect. I'll have to wait until this afternoon to try this out at the high school.

 

[markba633csi]

Sounds good, let me know

 

[Titanium]

Problem finally solved. Changing the current setting on the dipswitch did the trick. I’m still not sure exactly why this current setting worked and the lower current setting didn’t.

And right after I got this temporary drive up and running, I had to remove it because the new replacement drive from Tormach had arrived. At least I know that the 3DM883 actually works and I know how to hook it back up to the router in the event of another drive failure..