UM 2+ temperature Problem

[loderunner 0]

Hi,

i have a serious problem with our Ultimaker 2+. After moving to a new building it was not possible to print any more - no material came out of the nozzle. After some attempts i solved the first problem - the spring in the feeder was worn out. But the change of the feeder didnt help. After some further examination i found out, that the temperture was too low. I had to change the setting for PLA from 200° to 260° (!) to get some print. I went on with my tries, i changed the PT100 to a new one, so i could lower the temperature to 230..240°. Then i tried a new heater, waht didn't change anything. So i even changed the whole motherboard to a new one - and it didnt help. I still have to use 230..240° to make a print with PLA.

Has anyone an idea what is going wrong here?

Greets

loderunner

[CarloK 203]

I'm no expert in the UM2+, but search this forum for PTFE coupler. It is the white plastic (teflon) part inside the print head which degrades at temperatures higher than 230C. The higher the temperature the faster. 
When it degrades the inner diameter becomes smaller and it will become more difficult for the filament to get through. These are cheap replacement parts, just order a few. Quality differs so you might browse this forum for opinions. Both the Ultimaker and 3Dsolex parts were recommended.

[loderunner 0]

Hi,

thank you for your tip. I looked after the coupler, but its ok (looks like new) and so can't be the problem.

 

Is it possible the PT100 has a temperature resistence to the heat block? So that the measured temperature is less than the temperature at the nozzle? But i can't see any problem at this position.

Greets

loderunner

[CarloK 203]

You already tried replacing a lot of parts.
A temperature resistance between the PT100 and the heater block could be an explanation for your problems, but since you already replaced the PT100 I'd assume you there are no loose parts there.

 

Can you use a thermometer to confirm the temperature? This would rule out all electrical causes.

 

Other possible culprits:

- Feeder problems. Not enough spring tensions, or worn out feeder wheels (takes printing less than 1 spool of abrasive materials, e.g. glass fill, but also brass infill like materials)
- Clogged nozzle

- Printing with 0.25mm nozzle but slicing for 0.4mm
- Bad filament. I've cheap PLA here that's unprintable or some materials degrade over time

- Bowden tubes can wear out and have to much friction.

- Coupler degradation. You checked, but a smaller inner diameter might not be obvious to see.

[loderunner 0]

Hi,

thanks for your tips.

At last i got the possibility to make some temperature measurements. For this i removed the filament (some left in the nozzle) and the bwodwn tube and then moved a thermocouple at the place of the tube inside the nozzlem into the rest of the PLA. This way i hope i got real temperature values. It shows, that the temperature inside the nozzle is about 5° less than shown on the display. I measured at 200°, 210°, 220°, 230° and the small difference between display and multimeter value was nearly the same.

 

So: the temperature ist obviously not the problem!

 

And so all my attempts were useless for solving the problem.

 

When i removed the material for measurement i noticed, that it was impossible for the extruder to pull back the filament. The tip of the wire at the nozzle was preddes to a thicker area and so i had to pull out the bowden tube and cut the end of the filament wire.

And at the last try to print the extruding started but stopped after the first slice.

 

I am using the Bondtech DDG extruder (firmware changed and factory reset done as recommended by Bondtech) and i think, i will remove this extruder and replace it with an original one. Maybe this will be the solution.

 

THANK'S AGAIN FOR YOUR HELP!

Greets

loderunner

[loderunner 0]

Hi,

at last i could find the reason for all my problems: the hot-end cooling fan didnt run fast enough. After years it was worn out, so it didnt cool the cooling rib enough and so the material was too hot above the hot end isolator and stuck there. When i rised the temperature it worked, because then the temperature in the isolator coupler was high enough to melt the material there.

 

Now i changed the fan (the last part after changing feeder, bowden, pt100, mainboard, heater, nozzle, isolator coupler, hot end isolator [some of these multiple times]) and it works!

 

Greets from the now very happy

loderunner

[CarloK 203]

Great you finally found the problem cause. When you describe it like this it sounds all logical, but it was a difficult thing to figure out.  Thanks for sharing your findings so hopefully others can benefit.