UM2+ print head rubbing against enclosure after extrusion upgrade kit

[Lnox 0]

Hi!

Would love to hear from others regarding my issue.

My problem:
The new print head is rubbing on the printer enclosure when it's homing. The x axle limit switch is touched but it doesn't click (need approx 1mm more to click).

What I've done:
This is a very lightly used (less than 200h) UM2 that I've upgraded to + with the extrusion kit. I've followed the instructions with the ultimaker video and their manual. I maybe have done something wrong when it got to the pulley alignment section. What I thought I had to do was to loosen the pulley, push them outwards against their stopper and retighten them. While keeping everything parralel with the provided alignment clips.

I would love to see a more detailed version of instructions for  axle/pulley assembly and aligning, but I don't think it exists.

Anyone has ideas? I don't want to do something stupid. Of course I could try to move the limit switch or bend it, but I'd much prefer finding what is wrong and has moved instead, because it could create other problems

Cheers!

[Labern 774]

Hi. This was a common issue and you can just put a slight bend in the tongue of the micro switch so it clicks before the fan shroud hits the side of the machine. 

[Lnox 0]

10 hours ago, Labern said:

Hi. This was a common issue and you can just put a slight bend in the tongue of the micro switch so it clicks before the fan shroud hits the side of the machine. 

Thanks for the reply. That was my next strategy. Or maybe add a little something on the block that hits the limit switch. When you say it was a common issue, do you know why? I've found another thread about someone with a fan bent outwards that had the same problem (but that's not the case for me). My initial thought was that it had to do that I've changed something in the axles alingment, but the more I think about it, the lesser it makes sense. In fact, my real initial thought was that the + print head was wider than the UM2, but it doesn't seem to be the case.

I'd like to understand, as the upgrade kit is new, and the machine is "like new".

Cheers!

[Labern 774]

I think the fan shroud is just slightly wider and the head must have been very close to touching before you upgraded. My UM2 rubbed from the factory when I got it and fan shroud wasn't bent so I had to put a slight bend in the sensor.

Unless you skipped the belt on one side which isn't that easy then you alignment should be fine. There are alignment tools on to imagine that you can print to check/correct this. Or move print head to one side and see if one sliding block hits the pulley before the other side. 

[donmilne 2]

Similar story for me. I bought the UM2+ Upgrade Kit quite some time ago but only got around to installing it this past weekend. The instructions were lacking - I found that my printer has no ferrite core, also no fan connector in the middle of the control board. Apparantly this means that I was an early adopter and therefore I deserve to fail!  I understand I'm supposed to fit the fan connector to the J22 serial header - which I did, but I'm not sure I fitted it to the correct pins - I found no pictures to guide me, or even mention of the problem outside these forums. Is there supposed to be fan noise when you switch on the printer?  Somewhere on these forums said yes. I hear none, but the two fans on the print head do work. Is there a third fan?

 

Like the OP I also encountered the problem with the new print head being a few mm wider and therefore whacking into the left side of the printer case when it tries to home itself - the collision with the side stops it fully pressing the X axis limit switch. I did not like the idea of abusing the limit switch lever or drilling new holes in the case to move the limit switch.  Instead I used another 3D printer to print a little widget that slips over the top of the back x-axis slider block, adding width so it hits the limit switch a few mm sooner. It works very well and now my new UM2+ is working sweetly except for my doubt about that fan.

 

The upgraded extruder on the UM2+ seems to be a real improvement.

Edited October 11, 2023 by donmilne