Print head/rails popping out of the carriages

[Ross1234 0]

Hi guys

Our UM3 has been serving us pretty well although from time to time it decides to fall apart which obviously isn't ideal. It's easy enough to clip back together and get printing again, but I'm sure this is not a deliberate design feature! Has anyone else had similar issues and have a solution?

 

In the images attached you'll see both X and Y rails completely out of their carriages. Ouch!

 

Thanks.

[Smithy 1,141]

Hi

yes they can clip out for various reasons, often when it gets too warm inside, so be careful if you use an enclosure.

Just contact your reseller and they will send you new sidling blocks.

[Ross1234 0]

Thanks Smithy

Apart from the inconvenience of having the print fail, it doesn't seem to have had lasting adverse effects on print quality.

[Smithy 1,141]

No, at least not as long as the rods don't fall out again 🙂

The rods are just clipped into the sliding block and when the sliding block deforms a little bit due to a higher temperature or something else, it can happen that the rod falls out. And I think it can and will happen again.

 

So contact your reseller and ask for new sliding blocks, they are not expensive and then you have some if it happens again and you need to fix it fast.

[Travis7s 22]

Its happened to my UM3 as well. High enclosure temperatures definitely contribute to the problem. We were printing PC and it gets extra hot just due to the high build plate and nozzle temps. I didn't replace the sliding blocks but I did diagnose the print head bearings as going bad. Since replacing those a few months ago I have not had them pop out again.

[Ross1234 0]

Thanks Smithy and Travis. I'll take a closer look. I do mainly print with the higher temp filaments with the enclosure front cover on as you have both suggested could be contributing. The issue has become more persistent lately. I wonder if neglecting to lubricate the rails contributes too which I imagine could put more side force on the blocks causing them to tilt relative to the rods reducing their hold on the rods.

[Smithy 1,141]

I think the main issue is that the material of the sliding blocks gets softer with higher temperatures and then it happens that the rods slips out.

[Hops 3]

Can we just not have metal blocks that screw together and hold the bar permanently?

[Ross1234 0]

Thanks guys

I am yet to try new blocks and agree that this is something that needs addressing. It is the only real issue I have had with the printer but unfortunately it is a doozie. It means I need to factor this into timing of our workflow and means we do not feel good about running prints unattended.

 

I actually find this is happening from time to time printing with PLA so high temperature cannot always be to blame.

 

Apart from installing new blocks and presumably having the same issue present again in the future (no doubt right when it is least convenient), has anyone found/made a more permanent amd reliable solution? 

 

Thanks!

[gr5 2,071]

Some of the older printers I think had a different kind of plastic that gets old and cracks maybe?  Not sure.  But contact your reseller as they may just give you a new free set made from a different kind of plastic.  Even if it's the same plastic I'm sure it will work like new for many months.