[Solved] Filament sensor PTFE tube came off.  

RE: Filament sensor PTFE tube came off.

Mine came off and I lost it.  I replaced it with a longer version.  

RE: Filament sensor PTFE tube came off.

Posted by: @erlendds

Hi all, as I was unloading filament the small PTFE tube on the filament sensor simply came off with the filament.

I contacted support and they just told me to jam it back in. I did and it seems to be working fine now.

 

Putting this here in case someone else get the same issue, and to hear if you guys have any thoughts or tips on how to stop it from happening again.

It depends on how much work you want to invest. I have printed a new case with a PC4-M8 fitting. Actually I have rebuilt the complete extruder which already contains the sensor with controll LED.

That looks like this in principle:

As far as I know, Prusa provides CAD data, so it is easy to integrate a PC4 fitting into the case and reprint.

RE: Filament sensor PTFE tube came off.

@karl-herbert

Great idea.  

RE: Filament sensor PTFE tube came off.

@charles-h13

I think this is a small weakness and if people are interested, I will possibly rebuild the Prusa original PC4-M8 fairly and make the data available.

RE: Filament sensor PTFE tube came off.

I have just implemented this (PC4-M8). Would someone test this?

Mini_Fil_Sens_PC4_M8

RE: Filament sensor PTFE tube came off.

@karl-herbert

I will print them Sunday night.  

RE: Filament sensor PTFE tube came off.

@charles-h13

I quickly redesigned it and of course I didn't test it on my Mini, because I already used a different solution.
But I would be glad about a feedback and possible suggestions for changes.

RE: Filament sensor PTFE tube came off.

Posted by: @karl-herbert

I have just implemented this (PC4-M8). Would someone test this?

Mini_Fil_Sens_PC4_M8

 

Thanks for all the answers 🙂

I'll keep mine as is for now, but if it continues to act up I'll test this mod for sure.

RE: Filament sensor PTFE tube came off.

Hi, I just discovered this thread. Did anything come of karl-herbert's design? I downloaded it but when I sliced it I realized there's no thread where the PC4 connector is supposed to go.

I just had a tube come out so I'm quite keen on implementing this mechanism. 

-r

RE: Filament sensor PTFE tube came off.

@fuchsr

Not that I know of. I just pop mine back in whenever it falls off (which isn't that often). Works well enough for me.

RE: Filament sensor PTFE tube came off.

@fuchsr

For plastic you don't necessarily need an internal thread. The bore is designed for core diameter and the PC4 coupling can be screwed in with some care using a wrench.

RE: Filament sensor PTFE tube came off.

It worked for me.  

RE: Filament sensor PTFE tube came off.

A temporary solution is to increase the friction, wrap painters tape have a loop on the ptfe.

RE: Filament sensor PTFE tube came off.

I printed and installed Karl-Herbert’s design today. Looks good so far. 

RE: Filament sensor PTFE tube came off.

I also tested Karl's print.  It works well.  I have installed it on all 4 of my mini's and I have also placed it on one octoprint module that I am testing.  

RE: Filament sensor PTFE tube came off.

@fuchsr

@cwbullet

May I ask which of my designs you have printed? Does anyone have a picture to show me/us?

Thanks!

RE: Filament sensor PTFE tube came off.

The Mini_Fil_Sens_PC4_M8 file you posted 1/10/2020.

RE: Filament sensor PTFE tube came off.

@karl-herbert

Mine looks the same as fuchsr but in Urban grey PETG.  I started with Urban Grey Polycarbonate  Blend.  It just did nto do well in PC Blend.  

RE: Filament sensor PTFE tube came off.

@fuchsr

Thanks for the pictures - well done!

@cwbullet

Could not remember. For me, I built a combi solution incl. LED directly on the extruder. After some changes in the firmware, the sensor now works (filament change, pause function, etc.).