Ultimaker 3 misses print head change position resulting in disaster...

[Helvetosaur 4]

Hi there,

 

First time poster here.

 

I have been asked to take care of a couple of Ultimaker 3+ machines that are in a local school here; as a professional modelmaker, I have a fair amount of experience with other 3D printers (Stratasys, Formlabs) but my experience with Ultimakers is relatively limited.  In testing the school machines the other day, I found one of the machines has a problem when wanting to print dual material – model (PLA) in extruder 1 and support (breakaway) in extruder 2.

 

The mechanism/process that allows the machine to switch between which extruder is printing appears to be broken.  To switch materials, the machine head has go to a right-rear position to engage the slot which flips the lever that switches the extruder vertical positions. It seems the XY position that the machine sends the head to in order to flip the lever is incorrect - the head appears to go too far to the rear.  In doing so it misses the slot where the change lever should engage and at the same time it hits the rear limit - which causes it to lose encoder steps.  The result is that it starts printing the support material with the support extruder still in the upper position – the material is extruded in the air - but even worse, if I flip the lever on the head to switch extruders manually, the lost encoder steps result in a large misalignment (~10mm) of the succeeding model layers in Y.  The print has to be aborted at that point.

 

It is still possible to print OK with just extruder 1 (no support material), so the machine is currently usable in the same way as the Ultimaker 2 with a single print head.  Why I am posting here is because I am not sure if the problem lies in the firmware of the machine – the wrong position is stored somewhere and that it might be correctable with new firmware or some other software-level intervention, or if this is more of a hardware problem that will require changing some parts or electronics boards.

 

If anyone has any experience with this or has some ideas where I should start looking, I would appreciate it!

Edited February 26 by Helvetosaur
Added info

[gr5 2,005]

Oh an easy question!  Yay!

 

So this is from memory but I think it's under "maintenance" somewhere and then "calibrate lift switch" (the switch that lifts the right side print core).

 

The procedure is extremely simple and quick.  At some point you just push the print head around until the lift switch is in that slot and click a button.  That's it.  Do it a few times and test as it's trickier than you think but it's pretty darn simple.

 

There is also something called "reset to factory defaults".  Something like that.  That resets *all* of these positions.  I don't know how this could have been messed up other than a bit got flipped somewhere so I'm wondering how many other things are messed up on the "hard drive" (it's a solid state drive).  I wouldn't do "reset to factory defaults" unless there are other issues because then you lose all kinds of useful information and have to calibrate lots of other things.

 

Occasionally, on these printers with SSD, you have to reinstall the firmware.  Yes the SSD remaps all bad blocks but it doesn't know what the old values were before they got corrupted so you have to reinstall the firmware occasionally.  Everytime you update the firmware it also reinstalls all the firmware and will do so into the remapped "good" blocks on the SSD.

[Helvetosaur 4]

Cool, I will go in and try that tomorrow and post back here, thanks!

[Helvetosaur 4]

OK, that was indeed the problem, machine is now running correctly, thanks again!

 

I now have a problem with the other machine 😞 , will post a new topic..