Bad Motor?

[zuma 0]

I have just setup the Ultimaker today and the Y-Axis motor does not seem to be working correctly. The X-Axis moves smoothly, but the Y is extremely jerky and erratic.

If I manually move the head with the "Move Axis" function, I can see the motor jumping back and forth, even if I am moving it in only one direction. I removed the motor from the unit to see if there was any friction etc. causing the issue, but the same problem occurs.

The Motor appears to move randomly, and not in a smooth continuous direction as the other motors do.

Now, the strange thing is, if I plug the X-Axis motor into the Y-Axis port, it will work only in one direction. Also, I am able to get the head to "return to home", although it does it in this erratic motion on the Y-Axis, juddering back and forth "violently". The wiring appears correct in the motor and plug that connects to the board.

I just connected to Cura, and it upgraded to version 13.03, from March 1, 2013.

Thank you for any help you can provide.

 

[owen 19]

Hi Zuma

You may need to adjust the trim pot on the motor driver board slightly. See instructions in the wiki. Be careful though you can blow the driver board if you turn it too far clockwise.

 

[gr5 2,172]

Swapping the steppers was smart.

You could swap 2 of the drivers to verify that it is the driver. But make sure you ground yourself so you don't damage anything with static electricity, make sure power is off, and be careful not to bend the pins when you push it back in.

I'm going to guess that it is not the driver and something else wrong with the electronics but if you are lucky you can just turn the trim potentiometer a millimeter clockwise and all is good.

 

[zuma 0]

Thank you for the suggestions.

I tried swapping the drivers and the same situation occurs. I also tried adjusting the trim potentiometer but no luck.

One question on doing so. From where do I get a reading for the multimeter from the stepper driver? And what Voltage should I be getting? Luckily I read that my particular driver must be adjusted Counter Clockwise, rather than clockwise. However, I have no "Stop" as such, so it's impossible to know where it is set at (without a multimeter reading).

Thank you again for your assistance. I haven't heard a thing from Ultimaker since I sent them a support request. Are they generally backed up in responding to support requests? Should I not have marked it "Critical" (was that douchey thing to do).

 

[zuma 0]

OK, I've also just noticed that I have no control of the Extruder motor either (having never been able to print, I have yet to realize this).

When attempting to move the motor, nothing at all happens. I have tested this motor in my "X-Axis Port" and it works fine. So, I am basically having strange movement issues with my Y-Axis, and no movement with my Extruder.

Thanks again for suggestions. I'm guessing that the electronics board is faulty at this stage?

 

[zuma 0]

OK, so I've flashed the board again, and now my Extruder motor is working; so that is a good thing.

However, it basically appears that the Y-Axis is just randomly jumping around. It has "no idea" where it is.

Can anybody point me in the right direction on what might cause this to act erratically.

I was wondering if perhaps the EndStops were faulty and feeding it bad information on where to go; but I really have no idea what I'm talking about, as I'm just a beginner; so I'm taking shots in the dark.

Once again, all help is greatly appreciated. I feel like I'm so close.

Thanks

Z.

 

[gr5 2,172]

What are you using to move the steppers? (cura? ulticontroller? pronterface?)

I hope you put the pot exactly where it was as you can damage things (the driver) if you aren't careful.

I haven't tried it but I assume you can disconnect the cables to the Y endstops.

If I understand you correctly you swapped motors and you swapped drivers and the problem stays on the "y" commands when you command the Y axis. This strongly implies that there is nothing wrong with the drivers or the motors or the wiring to the motors. You also reburned the firmware so the only thing left is the board itself. It's time to contact UM customer support. They are very helpful but only work certain hours so email is probably fastest. They can probably ship out a new board as soon as you convince them that is what it is.

 

[zuma 0]

OK, something I think I missed.....

If I "swap the X and Y" wires directly the X motor works perfectly, when selecting and moving the Y-Axis it is now connected to. Suggesting that there is nothing wrong on the Y-Axis side (driver etc.).

The Y-Motor, now plugged into the X-Axis, continued to do the same thing, jumping around erratically when moving the X-Axis that it is now attached too.

I've tried using the UltiController and the Cura "Jog" tab to move the steppers, and they both result in the same thing.

So, this suggests that the problem is with the motor, and not with the drivers etc. Would you agree?

Yes, just for reference; the pot is exactly where it was (the "9:30" position) - which matches the X and Extruder drivers (from my understanding the Z Axis is a little "higher" which is where it is set (and never been touched).

Thank you again for your help

Z.

 

[gr5 2,172]

Aha! I thought there was a possibilty of miscommunication. "I swapped it and the same thing happened" isn't specific enough, lol. It wasn't clear if the problem stuck to the same motor or the same driver. Anyway, now it is clear.

Okay! That's great news. It's almost 99% in the wiring to the stepper motor. I would disconnect the motor and ohm out the connectors and jiggle the wiring while measuring the resistance. Or you could command the motor to move 100 meters very slowly and jiggle the wires. Then try the other direction.

It's common to have an electrical open in the middle of a perfectly good looking wire. Or it could be at either end.

If you can't get this working you can get a new motor from UM tech support. But I bet it's just a bad wire or connection.

 

[zuma 0]

I know, don't you hate it when people write things like "the same thing happened" - totally my bad.

So, if it is the motor; do you know of any location in the US that I can just buy from directly - yes, I'm being impatient; but after a day's worth of work putting this printer together, and then all this time trying to get it to work; I'd love to get one quicker than UM will send it from Europe (I'm west coast US).

Thanks

Z.

 

[zuma 0]

Dude! You are the man. You were correct. The green wire was sliced about 6 inches down (of course hidden inside the black cable wraps/passthroughs. The plastic was still intact, but clearly it was enough of a cut to sever communication.

Can you believe it?! I'm so happy right now.

So, for all those who might potentially experience this issue. Clearly the motor still operates, even when 1 wire is entirely severed. It will just act erratically.

Hopefully this will help others who might come up with this.

Thank you again gr5. You are owed a large drink.

Z.