Ultimaker 2 Self destruction

[magnusrm 0]

My ultimaker 2 wrecked itself over the night. It seems like it has stuck to the part or somehow crashed into it, breaking it off from the build plate and pushing it around.

Has anyone experienced anything similar? How did it happen, and what can I do to prevent it? I cant find replacement parts in the store, any tips?

I have used cura 14.09, and printed similar designs earlier without problems.

thank you

 

[Daid 306]

Looking at it I see that the screw holes that keep the fan bracket in place have no damage. That most likely means that the screws where missing or vibrated lose.

After that the bracket came lose, came under the printer head, causing hell.

Can you check if you can find 4 "M3x4" screws? I see there is 1 in the photo, but there should have been 4 in there.

 

[DidierKlein 729]

Wow that's a big mess ideed :mad:

Like Daid said the metal support for the fans seem to have come loose somehow, i imagine that during the whole process it came hitting the print multiple times.

From what i see in the picture you might need to replace the two fans (one looks melted and the other one's wire seem very short cut (maybe you can fix that yourself). For any replacement parts you should contact support.

Try looking for the short screws as Daid mentionned to see if you need replacements part for this as well...

 

[magnusrm 0]

It seems like the fans and the sheet metal bracket are the only component that needs replacing. Found all the screws. I guess they have come loose when hitting the printed part. The speed was pretty slow, 50mm/s.

 

[jonnybischof 60]

Just some thinking for future developments:

Approach #1 to prevent catastrophic print failures like these:

AOI - automatic optical inspection. Meaning point a camera on the printer and have a software determine whether everything looks as it should or not. If not - kill the print.

Probably very difficult to implement. Or is it? Not my field of expertise... It could even be "easy as pie" with a kinect (and it's software) which does similar things.

Approach #2:

Keep track of the stepper motor current - if any moving part bumps into something, this will be noticeable in stepper motor current because a stalled stepper wants to draw more current than a moving one.

Keyword: Stall detection and / or skipped steps detection

Common feature of professional stepper drivers, and maybe not too difficult to integrate into our printer's eletronics.

I'm actually working on that, but it will take some time. Spare time is hard to come by these days...

 

[magnusrm 0]

I find it strange that approach #2 isnt in place yet. I can see that motor torque can get high when the extruder accelerates quickly, but a crash should have a pretty distinct torque response.

 

[jonnybischof 60]

The problem is that the driver ICs which are used in 3D printers (DRV8825 or the Allegro 4899 something) are really just mere "drivers". They drive a motor according to incoming control signals. But they don't care about what actually happens with the motor. This needs to be engineered around the driver IC which just hasn't happened yet. (Or maybe it's about to happen )

 

[nallath 1,120]

Automatic detection is possible, but its hard to get right. You don't want any false positives or false negatives.

 

[magnusrm 0]

Hi.

Just to update this.

Since ultimaker support took so long to answer me (many weeks), I tried to install some fans with identical specs. Since the wires were torn off, I had to solder them on.

This didnt work, and I thought there was some bad connection etc, so I purchased a set of new fans and wires from ultimaker, which cost 72 Euro! A set of wires and two 1 euro fans with an ultimaker logo! However, I couldnt have a dysfunctional 3D printer, so I thought this was the only option. The whole purchasing process took about 2-3 months (they shipped the parts 2 months after receiving paypal payment).

The new fans and wires are installed, and the fans are still not working.

Im measuring 2.25 V on them when the fan speed is at 100%.

This process is the worst customer service I have ever encountered, and I must say Im really disappointed. When you have spent so much on a 3D-printer I would expect that they could send some wires for free and actually reply within normal time.

Any tips on how to get the fans running again?

[stu_le_brew 42]

sympathise for your problems, I had something similar earlier in life of my UM2, your problem could be in the connector plug for the two fans inside the plastic braiding, the wires seem to be just crimped on. The two fans are connected in series so if there is a connection error (which can be intermittent) then they both stop.

Suggest try moving the plastic braid while checking the voltage, if it varies this could be your problem

good luck

[magnusrm 0]

hi.

thanks for your reply.

I have also measured the voltage at the motherboard, and its the same there.

I notice that there is an empty connector marked "FAN" at the board. This has constant 24V on it (no matter fan speed). The yellow / green wire doesnt fit, but could it be used as an option? I guess the fan would be at 100% all the time.

Edited April 29, 2015 by Guest

[neotko 1,417]

Try the led pwm connection. The led pwm and fan pwm circuits are identical and if the fans work when you connect them on the led pwm then you could modify merlin changing the pins.h

Check the +\- and all connections before doing so (I almost broke the board 2 times so I prefer to truple check everything)

[magnusrm 0]

Hi.

thanks. will test and post results.