Sharing some experiences... and looking for spare parts
3 Months of PLA/ASB printing resulted in an extruder head blockage
After 3 months of around 3kg's enthousiastic printing, I noticed that my printer results became less predicatable. Open air gaps in the infill, see the attached foto. So first I thought to exchange the temperature sensor as lowering the speed increased the temperature stability. It was an easy and simple fix but didn't result in too much improvement. So today I thought: well, it could well be the case that some plastic resedue of previous prints have been collected and formed a blockage in the J-Head. And that hypothesis was being confirmed later.... with some nasty side effects.
Disassembling the J-Head
I started to disassemble the J-head. Took just some minutes and was fun to do. Very clearly visable, the PTFE tube was forming a 2mm black ring nearby the nozzle area and also I noticed a rip in the PTFE tube. I cutted away this dark area of the PTFE tube and put the metal parts in acetone. With some copper wire from a electric cable I was able to open the nozzle again and be able to see some light at the end of the nozzle-funnel.
Oeps... I put too much force on the J Head nozzle holder
After everything looked clean again, I started to assemble the head again... but this time with 13mm PTFE tube too short.... and in the process of assembling the J-Head I put too much force.. and heard a crack. Slightly visible, but its there. Not sure if it will impact the print results, but I'll see what will happen.
Printing again after cleaning-up
After this removal of the blockage, it looks like the extruder is working like it was in the beginning. But I'm affraid that the crack in the nozzle holder will require a replacement. Also I expect that the PTFE liner tube needs to be lengthy enough to feed the filament properly.
Question
I was looking at the Arduino site and also at the Shapebot site, but couldn't find any details where and how replace parts for the 1.75mm nozzle can be ordered. Hopefully someone can give me some directions...
Who knows where I can buy this PTFE Tube (4mm outside, 2mm inside)?
How to get an assembed hot-end or where to order the grey nozzle holder?
For reference, I've attached a picture of the piece which I cut off the PTFE liner tube
could it be that your temperatures were a bit high for this extruder with the ABS printing? Also, reprapworld has extruders in their shop, but not this particular one
Thanks ejo60, for your response.
I've looked at the RepRapWould.com site... as you suggested.
Is printing ABS higher temperature causing issues for the Materia printer head?
Yes, it could well be the case that my ABS printing with the Arduino Materia 101 printer head is exceeding its limitations. The maximum printing temperature was around 240 degrees... which is just 10 degrees above the temperature used to exchange the filament. A visual observation on the grey nozzle holder doesn't give any suspicious feeling. But that only what I can see from the outside surface.
What is the max. temperature allowed at Materia 101 head?
I'm not sure what the maximum temperature of PTFE - Teflon is, but I thought that it would be able to resist 240 degrees without too much problems. Unfortunately my extruder was blocked... could also be the combination of the filament, PFTE and maybe some residue for the previous ABS printing activities.
Spare parts to be found at RepRapWorld.com
On the RepRapWorld.com site, I've seen the J Head Compatible Hot End Set... but this one is missing the stud-end on top of the Nozzle Holder. Welcome to reprapworld.com | 3D printing experts | ReprapWorld USA
Before ordering... it would be great if I would know if this one could fit... so if any of you have similar experience or have a clue where to buy the PFTE or printer head that could fit, it would be highly appreciated.
I've send the Arduino Support team an email for directions
Hopefully the materia101@arduino.cc Arduino support team is able to provide me with a solution... since I would like to start to 3D print again. Some unfinished projects to complete I had send them an email Thursday and wait for their response.
I'm talking with our supplier to see what we can do to supply replacement parts. The softening point of ptfe is 248 C, Hence the j-head is limited when it comes to printing ABS.
Worst case scenario, the thermistor was not properly connected and the actual temperature was higher than the 240 degrees shown on the screen.
I wanted to let you know that I succesfully contacted Laura from the Sharebot support team.
She was very responsive in advising a spare Peek, Nozzle and PFTE tube. The price was reasonable, 40 euro's inclusive shipping as postal envelop. Payments were handeled via PayPal and shipping was within 2 days from Italy to Holland.
I'm glad that this knowledge is shared, if parts need to be serviced once in a while then we would all like to know where to get these parts. This thread is essential.
Bas: it would be good if you found the cause why the extruder melted the way you found. If that is temperature related, then is the thermistor the problem, or did the material fan not come on, or did you change the temperature settings for ABS?
In fact, it wasn't the extuder that melted... I think it was the PTFE that was burned.
I've changed the filament PLA/ABS a couple of times and think that every time a little residue was left.
This residue was build-up and blocked the extruder. This together with the higher nozzle temperatures for ABS must have caused the PTFE damage.
I had send them an email Thursday and wait for their response.