Racking gantry w/ 3.6.5?

[rsorensen]

Yesterday I loaded up version 3.6.5 and went to surface a project I'm working on here. I noticed I'm starting to get a lot of comm failures but what really caught my attention was a new sound coming from the 'bot when it would traverse in the X direction. Watching closer I thought I saw some racking of the gantry, and looking even closer I confirmed it. It appears that the X motor on the Y=0 side of my gantry is driving the whole thing and the other X motor is dragging.. or something like that. Where do I start chasing this one down?

My 'bot is a PRS standard with the 4G, 96x48. Things were working fine until the new control software and I'll probably go back to the previous [before the change I was running 3.4.x] version to see if I can't get this project out the door.

[rsorensen]

Update: The machine is a PRT, not a PRS!!!

[thewoodcrafter]

Sounds more like a mechanical problem, not a software problem.

With the power on to the machine can you move the far side of the gantry a little bit by hand?

If you can, you either have a dead stepper or a dead output on the controller board.

Software will not cause that.

[jerry_stanek]

When I tried the 3.6.x software I had the same problem where the gantry wasn't moving smoothly. But that was on my old PR with the 4g upgrade.

[rsorensen]

OK, I checked the far side of the gantry and no detectable movement there.

[zeykr]

First power off your control box and back on and check if motor works.

Next Switch your X wires at the control box. Does problem move to other motor. If so, problem is in control box - gecko or something. If not, problem is in motor or more likely wiring from control to motor. Look closely at the wago connectors and maybe reset the wires in them. They seem to be a common source of trouble like this.

[rsorensen]

I switched wires [X1 to X2 and X2 to X1 at the control box] and the problem didn't move. I pulled the wago connector on the motor and reseated it, no change. I reset all the wires in both connectors at the motor and then at the control box, no change. Do I have a bad motor?

[myxpykalix]

Before you go and change out the motor, i would go and revert to a previous version and see if the problem persists, if it does you can at least rule out a software issue. Thats a cheaper fix then a new motor, especially if you don't need it.

[ken_rychlik]

Take the motors themselves off and switch them.

Then you will know for sure.

When I tested some, I plugged them into the wire for the y axis and just ran a y move to make sure they worked.

Kenneth

[rsorensen]

I've tried switching software - reverted to 3.5.6 and then back to 3.6.5 with the same results. I dropped both X motors from the rails and tried turning the motors by hand. With the control box on the X2 motor [on the Y=48 side] turns by hand with some resistance, the X1 motor [on the Y=0 side] doesn't turn. With the control box off both turn freely. It seems like the X2 motor is bad.

To confirm, I plugged the suspect motor into the Z port and did an MZ move and the motor turns but slower than the X1 motor with a MX move. Now I'm confused - if the X2 motor is bad then why does it appear to be working when I do this? There's something I'm missing here!!

[ljdm]

Did you switch wires at the control box only? Possibly wiring is bad at the motor end? If you haven't yet, try hooking up the suspect motor to the good motor wire.

[zeykr]

Since you switched x1 and x2 at the control and problem stayed with same motor, it's not a control box problem. Placing the x2 motor on z seems to eliminate a problem with the motor (turns slower due to different unit values), so seems it's likely to be a wire problem in x2.

Double check all the wago connectors, but look real close for a pinched spot in the wiring, maybe near a roller that could have run over the wire at some time, or where there's a sharp bend in the wiring, or where the stress of the machine moving could cause stretching or wear. Often the outer casing of the wire can show little damage, but an interior wire can be broken or damaged enough to cause intermittent problems.

[rsorensen]

Thanks guys!! Does anyone have specs on the wiring? I've ohmed the cable to X2 and it appears good, fwiw, but think I may just make myself a new cable to eliminate that as a possibility.

[rsorensen]

I checked the cable again, everything looked fine but I replaced the cable anyway just to eliminate that as a possibility. Still had the same problem: the X2 motor can be turned by hand [with power applied to the control box], regardless of the port it is connected to. Sort of looks like it is a motor that has failed, doesn't it? Got a replacement motor overnight [OUCH] and installed it Friday... STILL have the same problem!

Hmmm...

The problem moves with the motor/cable when I plug in to different ports on the control box so it doesn't seem to be a control box problem, right?

The motor has been replaced so it isn't the motor that's at fault, right?

The cable has been replaced [NOTE: Only the cable, I re-used the Wago connectors] so it isn't the cable, right?

I pulled the cable off yesterday and looked really closely at the connectors and can't see anything obvious there other than the female pins *may* be a bit loose [how on earth would you go about testing them... or fixing them for that matter?] so ordered a new set of Wago connectors today.

Anyone have any other ideas of what I should be looking for/at?

Rick

[rb99]

Have you actually plugged the "bad" motor into the cable for the good X motor?

Completely switched the X motors to see if the problem follows the motor or stays to the cable?

RIB

[rsorensen]

Interesting problem here. When it first crept up I was seeing a problem that followed the motor/cabling, regardless of the port it was connectoed to. That lead to a motor swap which didn't fix things. I was still experiencing what appeared to be a motor/cabling fault that moved with the motor when I tried other ports on the control board.

After swapping out cabling & connectors and still not having a working X2 I again tried moving the connection to different ports and now the evidence pointed to the X2 driver. Multiple motors plugged in to the X2 port behaved the same way [with the motor pulled away from the rails I could turn the pinion by hand]. New driver is due today so I'll keep everyone posted.

This has me wondering though... is the original motor bad? Good? Since it is suspect, should I plug it in and try it, or is there potential for damaging another driver if the motor is bad?

[bernott]

Rick, I think you have a software problem because in your first statement you said after upgrading from 3.4.x to 3.6.x you noticed this problem, & you only reinstalled back to 3.5.x. Try reinstalling back to 3.4.x to the same version the day before this comm error started.

Just my 2cents