Bit of a Situation (Clogged up Nozzle and Print Head)

[Tafelspitz 5]

As the title implies, I'm a bit in trouble 🤔

I Started printing with Fiberforce Nylforce carbon fiber and at first, everything ran smoothly. After babysitting the print for the first couple of layers I then left to go about some othe business.

When I got back to the printer later, it was stuck with "Temp Sensor Error".  Apparently the print got loose from the bed and a big blob of material is now stuck around the nozzle and oozed inside the print head where it accumulated around the temperature sensor and what not (see pictures) 🤕
Since the carbon fibre is rather tough I can't see this getting easily removed from inside the print head.

 

Any tips, hints or general advise how to best solve this?

Short of replacing the whole print head I can't see how to best proceed.

 

Edited July 25, 2020 by Tafelspitz

[Carla_Birch 116]

You can try warming the filament up with a heat gun and pulling the filament away with tweezers as it becomes soft, just try not to aim to much direct heat at any wires.

[UlrichC-DE 108]

To cut a long story short I often do the following.

 

1. I remove the fan plate (4 screws with M3 on the sides)
2. i go to menu - > maintenance -> and heat the print head manually
3. Then I remove the material with pliers.

 

!!! Of course, this is not a harmless thing to do. Because the temperature nozzle is very high at 200°. Do not touch (do not eat etc.) !!!

 

I almost forgot.
Afterwards, I'll pray. That nothing is broken.

[Tafelspitz 5]

Thank you guys and gals 😃

 

Using the heat gun trick I got as far as disassembling the fan plate and heat coupler. Some prying with a screwdriver was also involved. Now the hotend is a different story... there's a thick layer of Nylon all around it and no way of getting to the screws.
Let's see what heating the hotend leads up to. I'll keep you posted.

However this turns out, I'm probably gonna end up ordering a new Olsson block, heater, sensor, and nozzle. Could have been worse, I guess.

Edited July 25, 2020 by Tafelspitz
Image added

[Tafelspitz 5]

The reason why I cut the wires is that I got the dreaded "heat sensor error" after turning on the printer, so I couldn't heat up the nozzle. I'll now try to unpack the hotend by means of the heat gun.

Messy business.

[UlrichC-DE 108]

Yes, it is always these little things that make it difficult to work.
Have you tried turning the screw that houses the PTFE coupling?
I don't have the whole thing memorized. But with this screw, you should be able to disconnect the nozzle from the aluminium support.

Edited July 25, 2020 by UlrichC-DE
typing error

[Tafelspitz 5]

I got the hotend free from its aluminium support. Heating the whole thing up and then turning the isolator got that one free.

After that I got a couple of chunks of the Nylon blob away and finally got through to the screw that holds the hotend to the aluminium plate. Whew.

I have already ordered all of the necessary spare parts. Maybe I can yet salvage the ruby nozzle, but it's going to be tough and messy.
Maybe I'll be able to dissolve the Nylon filament in acetic acid (don't worry, I'm a professional) but then this may attack the brass as well. But it's at least worth a try. If it goes wrong or doesn't work I'll be no worse off that now.

[Oliveros 11]

Just heat it with a torch and take it off, if all you are trying to salvage is the nozzle, it'll work.

[Tafelspitz 5]

Brilliant idea.
Gonna try this later. Thanks!

[Tafelspitz 5]

The blowtorch did the trick.

I wouldn't say good as new, but I guess it's still very much usable. Thanks again! 😃 👍

[gr5 2,072]

If the brass got red hot then beware that it will be softer going forwards which doesn't affect printing but means you have to be careful when changing nozzles.  Try not to go over 1 Nm of torque.  For example if you use a 7mm socket but no wrench - just socket in your fingers - 1Nm is about the limit of torque an average adult can produce using absolutely all your finger strength.  I can't quite get 1Nm.

[gr5 2,072]

@Tafelspitz - if this happened to you once, it will happen again.  It's not hard to get nylon to stick very well to heated glass.  Key elements are:

1) higher bed temps are better up to around 100C - usually 80C is plenty hot and that's what I do.  Nylon gets softer and softer the higher the temp but still quite firm  (like putty) and then eventually melts around 120C.

2) Squish - this is most likely what you did wrong - see video

3) Use brim

4) Use one of 3 PVA glues (if you use glue stick - you must thin it to get extra good sticking but thinning shouldn't be mandatory for Nylon except maybe extra large parts or if you aren't using brim)

 

Better details here:

 

 

[Oliveros 11]

Glad it worked out.

[Tafelspitz 5]

After replacing the hotend and almost every other parts in the printhead known to mankind, the printer is now up and running again.

Kinda.

Alas, I must have unplugged the fan wires somewhere along the cumbersome process of threading the sensor and heater wires. So back to taking everything apart. Again 🙄

[gr5 2,072]

It gets easier and faster each time you take it apart.

[Tafelspitz 5]

Yes, indeed! 😄
Turns out I inadvertently fryed both fans with the heat gun in the process of freeing the Olsson block from its nylon mess 🥳
There I was paying careful attention not to overheat any wires and other parts, but obviously I messed up with the fans. But then the heatgun is kind of a blunt instrument.

Anyway, replacements are already on the way, not much of a problem.

On the bright side I got to know the whole printer better.

You learn the most about any instrument or tool by taking it apart 🙂

[Tafelspitz 5]

I am very happy to report that after replacing the two fans everything is now up and running again. Printing the first post disaster part as I'm writing this. It runs very smoothly indeed. In fact, the two new fans seem to be significantly quieter than the old ones. So I gained something out of the disaster after all.

And I did learn a great deal. So here's to a happy end.

Thanks again to all of you who stood by with sound advice. Very much appreciated.

Edited August 4, 2020 by Tafelspitz

[Carla_Birch 116]

Happy to hear you are all back up and running fine again 🙂