Bad driver troubleshooting?

Has anyone had a Stepper Driver fail on them?
I think mine needs replacing.

Yesterday I turned on my 770 Series 3, and referenced X,Y, Z.
Y and Z referenced just fine.
X traveled all the way to the right, and got stuck on the limit switch.
The stepper motor kept trying to turn, and the mill was shuddering.

I had to E-stop and jog off of the switch.

Now the X axis motor sounds terrible, and REAL noisy.
Also when manually jogging in X, the motor will reverse by itself, not respond, or act intermittently goofy.

I'm thinking this is a sign of a blown x axis driver?

Any knowledge from you guys, that have had motor and/or driver fails is greatly appreciated.

Pulled the driver off and found this!
I think I found the problem.
Attachment 469408

I made a post about the connectors failing on the stepper drivers a couple year back, all 3 of mine failed, one obvious as you experienced, the cure here in my case was to change them out. I have not had a problem since, the problem I think is the connectors are not heavy enough to handle the currents involved over an extended period of time........

I will see if I can find the post and post the title here.

some unusual design, however. Limit switch must disrupt power supply when activated. Otherwise it is not safety component but a regular sensor.
My version is:
The axis traveled wrong way for whatever doesn't matter reason. Activated stroke end limit switch was ignored because it is not designed for safety. The axis movement ends while motor was still trying to move and here at this very moment electric current raised high enough to blow the contact.
Wrong points of design:
1. General conception not using absolute encoders.
2. Sure, the reason why the axis was not referenced. Maybe some really small mistake or sensor misallignment.
3. Software limit. Some machines use double software limits : user defined plus system. This control system didn't used any at all.
4. Drive ignored overcurrent.
5. Power supply unit ignored overcurrent.

Tormach driver failure is the name of one of the posts, seems to be very common.

there are several posts about this.

edit: I had several pics of my repair which I cant find on the forum.

Something going on here.
I had same problem, x stepper started making a bad noise while it was homing. it was moving and losing steps and it just sounded bad. It also went right over limit switch like it was bad or something. Had to kill power, pull vise, 4th axis, Sheetmetal and axis coupler drive cover, back axis off limit switch by slowly turning the ball screw coupler by hand. Pp seamed confused and would not stop on limit switch when homing even tho it was working fine. As mentioned above it would jog in wrong direction and shudder and go over home switch. I did a pp update to same version and reset control. Limit switch now works and machine homes correctly. Ran it most of today prepping stock because I dont trust it now.

Oh and I went thru all the connections and each of the steps outlined in manual for trouble shooting and found nothing. Until reading this post I figured it had to be gib sticking.
I have a stepper, driver and limit switch setting in my tormach cart. Because I just figured this was not the end of this problem

The limit switch seems to be working.
I removed the front cover and pressed the limit switch by hand, and the X green light lit up on the display.
So it's sending a signal.

I guess I will be ordering a new Driver tomorrow.

Quote:

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Originally Posted by RussMachine

The limit switch seems to be working.
I removed the front cover and pressed the limit switch by hand, and the X green light lit up on the display.
So it's sending a signal.

I guess I will be ordering a new Driver tomorrow.

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I went back and pulled connector again and it was just like yours. Burnt connector and a almost melted #310 wire.
Dont know how I missed this before. Anyway I ordered a new driver and limit switch. Will get machine back up and running and then look at old driver and maybe repair connector and keep for spare. And keep new limit switch as spare

Just a note:
In the owner's manual, under "Troubleshooting a defective driver", it states that a defective driver will not recognize the limit switch.
I guess that's why it over-traveled while referencing. :(

If the driver fails to reverse you could get this issue.

Normal homing would

1. Move to the limit switch until it trips and then slow to a stop
2. Reverse and back-off the limit switch slowly until untripped
3. Move to home position

If the drive doesn't reverse, in step 2, it would run into the stops

I received my new stepper driver today, and that brings up another question before I install it.

Do the PA Settings have to be set the same way that the old driver's were set? (White on/off switches on the Blue plastic)

My old driver had numbers 2 and 6 turned OFF.

I'm guessing that I need to also turn OFF numbers 2 and 6 on my new driver?

Quote:

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Originally Posted by RussMachine

I received my new stepper driver today, and that brings up another question before I install it.

Do the PA Settings have to be set the same way that the old driver's were set? (White on/off switches on the Blue plastic)

My old driver had numbers 2 and 6 turned OFF.

I'm guessing that I need to also turn OFF numbers 2 and 6 on my new driver?

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I matched all the dip switches from old to new. Y and z drives were also the same. A axis driver was different and had a different leadshine driver also. I also used heat shrink tubing on the yellow 310 wire and the one next to it. They both had melting of insulation near connector.
Cleaned the wire ends and coated them with dialectric grease. Clamped into connector and checked for solid connection.

Thanks for the quick reply MtnDew.
I'll install it today.