filament clogging UMO+ /w imgs

[FinnFrotscher 0]

The printer is 2 months old. I printed in many layer-heights, temps and speeds with good results.

Suddenly the Printer stopped pushing filament through the nozzle.

I opened it up, found this situation, cleaned it, closed it, used it and it happened again immediately.

 

printhead disassembled and ordered

It seems, the filament melted before it got into the peek isolator and clogged the hot end isolator.

 

hot end isolator coupler top view:

What, why, and how to fix?

Edited August 24, 2016 by Guest

[neotko 1,401]

By the look of the barrel near the aluminium block, you already had a leak there. Did you solve it by tightening the nozzle? Or did you rotated the peek with the barrel to close the leak?

The think it's that to clean that you might need to assemble all, set at 90C and pull that filament (if it's pla 80-90 and 110-120 or so for abs).

My theory it's:

You did tight the barrel (hense the marks on it) to close a leak. That could make that the barrel did screw futher in the top peek, pushing the coupler and deforming it overtime. By the look of all I think you just need a new ptfe coupler. The best way to test a coupler it's to pass some filament on it (with the coupler outside ofc) and 'spin' the coupler to see if woobles. If woobles it's damaged, if the filament has a hard time to go in also it's damaged and if it's brown it's also damaged.

Ofc it could just be a clog of dust and dirt that deposits overtime inside the nozzle. To clean that you need a few good atomics, like 8-15 until all its as clean as a dish on sunday.

[gr5 1,251]

neotko is an extreme expert at UMO - more so than me.  So read his advice carefully.  Some other ideas though more specific to your question - if you do retractions that are too long the heat moves upwards with each retraction.  And future retractions then pull the heat higher up each time.  If it gets above the white teflon part it's a problem.  Also make sure your bowden is all the way in so there isn't much room for filament to expand above the teflon.

What is your retraction distance?  I use 4.5mm on UMO but my bowden is nice and tight (no play).  If you do get a new teflon, get it from 3dsolex as theirs is a newer material that is more durable.

Consider maybe putting a small fan blowing on the upper block area to keep the teflon cool. UM did exactly that in the UM2 (the rear fan).

Edited August 24, 2016 by Guest

[neotko 1,401]

Yeah I did that too until moved to um2 hotends

I uploaded some time ago ptfe fans holder for umo+ https://www.youmagine.com/designs/ptfe-cooler-umo-for-30x30-25x25

Also the TFT of 3dsolex, if your coupler it's dead, should be really nice to have. I never tested it but if it's half as good as the ones for um2 then it's a winwin. A normal ptfe coupler last around 100-200h on a umo, and tft/tfm couplers can last 500-2000h so it's a time saver.

[FinnFrotscher 0]

Thank you for your tipps and advice. I will try tomorrow and tell you right away!

[FinnFrotscher 0]

Thanks for the help. I think its working now.

I cleaned the nozzle and all the parts very very much, tested the coupler (everything fine) and so far i dont have problems. i think the issue was some alien parts in the nozzle that stopped the filament from pushing through.

Finn

[gr5 1,251]

If the printer is in a very dusty environment it's best to make a filter to clean the filament as it enters the printer. There are quite a few out there - search for them on youmagine or thingiverse.

[LePaul 296]

Yeah I did that too until moved to um2 hotends

I uploaded some time ago ptfe fans holder for umo+ https://www.youmagine.com/designs/ptfe-cooler-umo-for-30x30-25x25

 

Would that work on a UMO board?

[neotko 1,401]

If you have somewhere to plug power of the fan yeah

[LePaul 296]

I wasn't sure if the mainboard did

Or use the external power idea you linked in the youmagine post

[neotko 1,401]

I think there's room on the umo board for some extra 5v fan? I really not familiar with it sorry @lepaul but yeah it should work with the dualfancap perfectly (that's how I used it). The key it's to install it on the oposite side of the hotend so you don't get cooling hitting the alublock but just the upper peek/coupler area

[LePaul 296]

Right, so on the backside, like the picture from youmagine. Not sure I'll do that upgrade right away but good to know...nice way to add life to the peek/coupler