HELP! X just died and I don't know why.

This is a manual mill which got converted to CNC and powered by LinuxCNC. Everything was fine until just an hour ago. It finished a part and when it homed back to X0Y6 for me to swap in the next item, I noticed it was ~0.020" off on X. I have an independent DRO on this machine which allows me to keep watch for any abnormalities. I went to jog it back to X0 and it started jumping around as seen in the video linked. I have connected the Y motor to the X motors harness and the results are the same (the video shown here is of the Y motor temporary connected to the X motor harness). I've attached a screen shot of the scope. I'm using a Leadshine driver for X. I suspect all these Chinese drivers are junk. Ive check the direction signal to the driver with a meter. In one direction, it's a constant 4.2V and in the other, it's a consistent 0V. Any thoughts and help?

The Youtube video is at:

Hi

All that remains is to swap the X motor across to the Y driver and wiring and for it to work properly and you have it conclusively.

I specify wiring, because it is just possible the problem is a connector or wire. Have a really careful look and put a meter on the lines whilst wiggling about.

I have never found a problem with Leadshine drivers, they are 'fit and forget'.
However there are genuine Leadshine, good copies and black boxes with similar writing on.

regards

This one is a genuine Leadshine. I had a Chinese copy (Longs Motors) originally on X, but one of the connectors started melting....In a way that you might first think it was due to a loose connection at the screw terminal. After further examination, the pin fit of the green connector was loose and caused excessive resistance, heat, then melting. So, I bought a brand-name Leadshine M860 from leadshineusa.com. That's the driver that appears to be having issues.

In the scope, doesn't the on-time seems really short?



One thing I can say for sure, I'm not cheaping out on the next conversion. I've got a BP Series 1 CNC that I'm next bring back to life. Just ordered a 7I76-5I25 PLUG-N-GO KIT an hour ago. I'm doing Gecko G203V drivers. (please let me know if you think I should choose different drivers). I'll be ordering those this afternoon. The chinese VFD has done well on the other, so I will reorder the same unit for this machine.

In the scope, doesn't the on-time seems really short?

I couldn't really tell from that, I assume I am looking at X step?

I have always found it far more fruitfull to carry out thorough elimination tests using known good axes. In a few tests you can narrow down to the individual component if you are thorough and do not make any assumptions.

Connect the X output from the BOB to Y input. Y axis moves OK - eliminates any problem with X step generation and wiring to the driver. .. and so forth.

As far as Gecko's go, I have never used them, too expensive here, but they have a good name and you should get good after sales service if necessary.

Interesting desktop! Trying to work out if it is something real or a still from a game.

regards

ArcEye wrote:

Interesting desktop! Trying to work out if it is something real or a still from a game.

That is the space shuttle discovery being taken to launchpad. I've attached.

ArcEye wrote:

I couldn't really tell from that, I assume I am looking at X step?

Yes, that is my X step.

Hi

Fix direction pin to ground.
Still same problem.... Driver.

Regard ground cabling...

Mike

I'm back up! The machine went down just before all the snow, so I didn't touch it until a couple hours ago. I turned the machine back on and the driver faulted a couple times, but sometimes the motor would operate. Turned out to be a bad connection at a large Deutsch connector that interconnects signal & motors between the control cabinet and the mill. One of the phases was intermittently going open. When I checked resistance, it was making a good enough connection to not show trouble.

Thanks for everyone's help.