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anon4321

There should be big RED warnings on every page of the UM site...

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It's dead Jim. But Bones, it only printed like 7 things, I'm sorry Jim, it's dead. There is nothing I can do.

Well, unfortunately, I found out something about the stepper motors and drivers in the Ultimaker.

Back driving them (doing something that causes them to rotate at a good speed) with the power off causes them to produce enough voltage (they become little generators) to destroy the driver.

This is a poor design if you ask me. There should be some kind of clamping to prevent this.

I was funtzing with the extruder unloading the filament by spinning the big gear and noticed that even with the UM completely unplugged (no power, no USB), the indicator LED on the thermocouple amp board was pulsating on.

Also, whomever deigned the board and flipped the two drivers sockets on the left 180 degrees and did NOT silkscreen a huge message stating that they are flipped should be shot.

So I now have at least two dead drivers and worse yet the pin that signals the extruder is apparently dead now. So now I need to replace two drivers, the audrino. I wonder if I killed anything else on the shield or the TC amp.

Very unhappy at the moment.

 

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meant to add that this is probably something that is specific to the extruder since the gear ratio allows you to get the motor spinning pretty fast. I'm not sure that you could drive the XY axis fast enough to cause the same effect.

I'm also not sure that having it powered would have helped but that would have at least allowed the PS to help clamp the back EMF.

So be warned.... don't manually drive any of the steppers by hand.

 

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Bummer, wrecked my fair share of stepper drivers for sure. The fact that they blow instantly if you install them backwards should definitely be screened on the board... or... even better... the standard for a stepper driver should be an asymmetrical connector.

Anyway, seems like you're in the US... get your replacements from Pololu. Shipping is quick and the Black or Purple versions are both significant upgrades since they don't need fragile heatsinks. Purple ones are quieter too, but you have to mod your firmware to double your steps per mm.

 

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Damn, guess I've been lucky then. I've shoved the head around A LOT over the years, been quite rough with it too. And I don't mean moving the head back after a print here and there, I mean sliding it around all over the place quickly. Whenever I've oiled the rods for example. I don't think I've moved the extruder gear around much though.

 

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I've moved the printhead around a lot, on multiple machines. Never fried the driver boards though.

Also; I understand you are frustrated, but your tone isn't going to help you get the help you need. Nor will it convince anyone at ultimaker any faster to make changes. Politeness goes a long way...

 

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The stepper drivers indeed seem to be more sensitive to induced voltages than it was thought up to now. I recently http://umforum.ultimaker.com/index.php?/topic/4878-broken-stepper-driver/ it. I could imagine that the damage was actually caused by voltage spikes due to the strongly skipping motor.

About moving around the head: it makes a difference if the head is moved fast or slowly. In both cases the stepper driver could be confronted with slow electronics death over time. But certainly it's less pain for the electronics if the induced voltage is smaller (means slow movement is better).

I suggest that http://wiki.ultimaker.com/UltiStepper_Driver_1.0 is updated with some warnings what might cause damage.

 

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In all honesty, the whole UM 1.5.x board design is crappy. After all, it was designed by a software engineer and a mechanical engineer.

BUT, I've never, ever, seen a stepper driver being destroyed by the generator effect. And I've seen LOTS of machines (COM port counter on my machine is over 130). We regularly move heads and extruders while the machines are off.

It IS however, possible to damage the stepper drivers by adjusting the power while the machine is on. It does not always happen, which is why some people assume it's possible. But this is generally how people blow up those drivers.

Layout wise it makes sense to have the extruder drivers switched. But you're not the first to be caught off-guard by this.

(Rotating the steppers 180deg around is a sure way to make them explode)

 

We will be switching to the UM 2.x.x boards in the kits soon. These no longer have the stupid mechanical pots.

 

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Someone pointed out that I wasn't being polite. The only part I would clarify would be obviously that you shouldn't shoot people over bad board design. I thought the humor was implied.

Anyhoo, I think the key is the feeder motor. Given the gearing on feeder, it's possible to get the motor spinning very fast using the big gear and that probably produced enough voltage to kill the stepper driver.

The drivers have a max supply voltage of 35V, my guess is if you spinning that big gear fast enough that a voltage higher than that is produced, it's dead Jim....

If anyone has a spare driver and time, remove the board and then the Arduino and disconnect everything and spin away! See if it still works after that....

In case you are wondering what the heck I was doing: http://www.thingiverse.com/thing:40334 See that little knob... yeah that's a BAD idea!

 

 

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Daid,

Actually, I think the PCB is designed fairly well. Or at least better than I could do. Although I do believe there should be a screaming warning on the board about the inverted drivers. I can understand that because of the physical placement of the connectors, the layout is better with the side-to-side flip.

I actually tried to redesign the board to add external power for a HBP and possibly external power for the stepper drivers.

Eagle is not for the novice so I gave up. Would be an interesting project that I might tackle again...

 

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Anyhoo, I think the key is the feeder motor. Given the gearing on feeder, it's possible to get the motor spinning very fast using the big gear and that probably produced enough voltage to kill the stepper driver.

The drivers have a max supply voltage of 35V, my guess is if you spinning that big gear fast enough that a voltage higher than that is produced, it's dead Jim....

If anyone has a spare driver and time, remove the board and then the Arduino and disconnect everything and spin away! See if it still works after that....

In case you are wondering what the heck I was doing: http://www.thingiverse.com/thing:40334 See that little knob... yeah that's a BAD idea!

 

Challenge accepted!

I'll report back if I can make stuff explode, for fun an profit.

 

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Well, I concluded that I am probably stupid. Sander IM'ed me to see how I've been getting along. I told him the UM1 was working well until I broke it. Then he laid down this tidbit:

"Putting in the stepper drivers the wrong way around is indeed deadly (for them), but when you are switching around stepper drivers to test, note that the E motor is indeed positioned in the opposite way as the other, but there is also a firmware safety measure that it doesn't work unless the print head is at least 180ºC. This is done so you won't damage anything trying to extrude PLA through a cold nozzle."

Notice that last part about the safety measure?!?!?!?!

I did when it hit me that the reason WHY the driver appeared to not work was because it was disabled by the FW! DOH! So when I switched it with another putting the other in the wrong way, that blew the replacement.

However, I'm willing to bet that the original was OK but wasn't enabled due to the cold hotend. Furthermore, the audrino is probably fine and doesn't need to be replaced... I just need to preheat the hotend to see if the audrino is OK with a good driver in the extruder socket...

This is probably why no one else has since this issue. Probably because it doesn't exist...

Sigh... It sucks to be stupid...

 

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; I understand you are frustrated, but your tone isn't going to help you get the help you need.

 

I think you read the tone wrong. The tone was humorous and only a *little* frustrated. Anytime you read a "tone" that is objectionable. Stop. Pretend the writer is laughing, very hard, and read it again. Make absolutely sure that you aren't seeing "tone" that is not there. This is a very common problem on the internet and with texts and emails.

 

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I received and replaced my drivers with "blacks" from Pololu and things are working OK now. I think I need to adjust the current.

I really think it was my misunderstanding that made it seem to me that the feeder driver was burned out by me turning the extruder.

When I went to diagnose, I didn't flip the driver correctly and that killed it. And of course like an idiot, I burn out another before I realized that the orientation is flipped.

Since I'm the only one that appeared to kill a driver by turning the feeder, I suspect that it was just me not understanding the safety feature of the feeder control and the need for the hotend to be up to temp before the feeder driver is enabled.

 

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