Tree Journeyman 325 Z Axes Servo Error

Machine was running fine, making parts as usual. Then...I left it sit for 3 weeks and now it has a big problem.

Jog Z down it works - jog Z up and it errors out with "Z Servo Error"
I reset it, Jog the Z up it works - jog Z down it errors out.

This problem is not going away and I'm shut down. I've shut it off and rebooted several times and problem still remains.

Some of my trouble shooting: I swapped the Z and Y cables at the servo card and no change.

I've visually inspected the Z ball screw/nut, no obstructions, screw is oiled good.

Any help would be appreciated. Thanks in advance.

I have a Journeyman 425 with a Dynapath 40 and Baldor drives. The first thing I would check is the lag error. Then I would check the tach and signal voltage.

For lag error, go to mode select, set up (?), then choose display lag error (TM4?). I'll have to check specifics when I get home.

This will display the lag error instead of the distance moved on the main page. set jog to 1 for low, override to 50% so the axes move very slowly. Move Z a small amount and see if the lag error remains (axis doesn't move) or is close to zero (axis moves). Hopefully the error doesn't get large enough to trip the e-stop.

The fact that it moves in both directions, even though you need to reset between direction changes, is a good sign. It indicates the servo is working.

Also, go to the display status page and see what the error codes are. Let me know what you find.

After lots of troubleshooting I've narrowed it down to a control transformer. I checked the axes lag like you described as well.
Took Z motor apart and cleaned carbon out.
Plugged X cable in to it and it worked perfectly. I ordered a new transformer. Should have today hopefully.
Thanks for your reply!

OHIOTURBO6 said:

After lots of troubleshooting I've narrowed it down to a control transformer. I checked the axes lag like you described as well.
Took Z motor apart and cleaned carbon out.
Plugged X cable in to it and it worked perfectly. I ordered a new transformer. Should have today hopefully.
Thanks for your reply!

Click to expand...

This was not the problem. Still has same problem. I'm out of options.

Bummer. Lets start with some relevant details. What type / model control? Type & model of drives?
Also, when you switched drives did the Z card drive a different axis successfully? Are you able to jog Z in one direction through full travel? Then reset the machine and jog it in the other direction full travel?

If it's an electronic issue that happens with Z only, using any axis drive card, then check for loose screws / broken wires at the card connector for Z axis. Then check all other connections between the card and the motor. Perhaps you have a loose or broken wire, especially in the plug at the servo motor due to vibration. It could be an intermittent connection most likely on the encoder or tach pins. Unplug at the servo and check continuity for every wire back to the Z card connector. You may need to disassemble the plug and look at the wire to pin connections visually.

Otherwise, it could be something mechanical. I see you visually inspected the Z ballscrew, but I suggest removing the cover under the head and using the manual crank to move Z (or turn the belt up top). See if it moves freely in one direction then binds in the other. Can you move it through full travel freely in both directions?

Good morning we are having a problem with z when I reference x,y,z I'm having problems with z it's not reading 0 it's reading +3.82 and we can't get it to do up and down we replaced all brushes 2weeks ago and the machine was running fine and z was fixed but now it's doing the same thing should we check the brushes or the motor we getting power just z will not move at all

I got mine fixed. Ended up being a bad tachometer in the motor. I ordered a replacement motor to get it back in service and had the bad motor rebuilt. Now we have a backup plan.

I would swap the Z motor with the X motor (pulleys are different so swap those too). Don't adjust any of the pots on the servo amps! I did and had to learn how to tune them all. Took a lot of time when you've never done it before.