[Titaniumboy]

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.

Attachment 501456
Attachment 501458


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

Attachment 501454

Attachment 501460

Attachment 501462


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?

[Contract_Pilot]

I Believe the 24R uses a ECM Board and it uses the enable signals.

See Schematics.. https://github.com/tormach/Repair-In...ontrol%20Board




From the manual it is a ECM1 1.5 Board they are using.
Attachment 501486



I have notes some place here for the IDC break out but I cannot locate them but you can pull it from the schematics.

[Titaniumboy]

Hello Steven,

Thank you very much for your help.

I have a picture of the control board and it says "ECM1V1.5".

Thank you for the Github link. I will look at it and see if I can make any sense of it.

I'm got a gap in my electrical knowledge in that I don't even know what kind of signals that the ECM is sending to the stepper driver. The temporary 3DM883 has a switch that configures the control signal voltage to either 24V or 5V. I'm not even sure if the control signals are DC or AC?

Would I expect to see a constant voltage on pin 3 of the ribbon cable, or does voltage only appear when there is a Step or Pulse signal issued?

I Believe the 24R uses a ECM Board and it uses the enable signals.

I traced the 10 pin IDC header on the Tormach version of the 3ND883. It appears that only pins 3, 4, 5, and 10 are connected to other components with all the other header pins not connected to anything. It looked like only header pins 1 thru 6 were being connected with the Tormach 6-wire ribbon cable. The 3ND883 has screen printing underneath the 10 pin header that shows "OPTO" for pin 3, "PUL-" for pin 4, "DIR -" for pin 5, and ENA-" for pin 10. The 3ND883 and the 3DM883 say that the ENA is "usually left Unconnected (Enabled)" and "ENA signal is no-connected as default", respectively.


Thanks again for your help.

[Titaniumboy]

I'm got a gap in my electrical knowledge in that I don't even know what kind of signals that the ECM is sending to the stepper driver. The temporary 3DM883 has a switch that configures the control signal voltage to either 24V or 5V. I'm not even sure if the control signals are DC or AC?

Thanks to Steven's link to the Tormach Github files, I was able to verify that the ECM is sending +5V DC control signals to the stepper drives. I will just need to make sure that the 3DM883 S2 switch is set to 5V and not to 24V.

After poring over the 3ND883 and 3DM883 manuals for what seems like the tenth time, I finally 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 actually correspond to 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. Keeping my fingers crossed.

[Titaniumboy]

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..