Go to homepage
3D Printing
3D Printing Service
FDM SLA/DLP SLS MJF DMLS/SLM Material Jetting
CNC Machining
CNC Machining Service
CNC Milling CNC Turning Surface Finishing Part Marking
Injection Molding
Sheet Metal Fabrication
Resources
3D Printing Guide CNC Machining Guide Injection Molding Guide Metal 3D Printing Guide Knowledge Base Webinars Help Center
Get instant quote
Jun 2016
1 / 6
Jun 2016
Jun 2016
lemonade
Jun '16

I’ve recently assembled my first 3D printer, a CTC i3 pro b (Reprap prusa i3 derivative), but its just printing air.

The 1.75mm PLA filament supplied with the printer starts feeding into the extruder (seems to be based on an MK7) by the stepper until it starts to go into the feed pipe where it jams and then the stepper starts skipping.

I disassembled the extruder and checked that the filament moves past the stepper OK and is gripped well by the teeth. The nozzle and feed tube were not blocked but it was difficult to insert the filament into it and I noticed that the hole in the metal feed pipe was not quite center at the ‘out’ end. As can been seen in the pictures (sorry about poor focus) this means that the flow tube does not quite line up with the hole in the other end. Could this be normal or should I go back to the supplier?

nozzle_feed_pipe.jpg
nozzle_feed_pipe.jpg2845×800 918 KB

After putting it back together it still jammed in the same place, I was able to force the filament further in manually but it took quite a bit of force and only spat out a little from the nozzle and then jammed again. If is not an issue with the tube do I just need to up the stepper current and maybe lube up the tube (I’ve heard of people using baby oil?)

  • created

    Jun '16

  • last reply

    Jun '16
  • 5

    replies

  • 2.8k

    views

  • 5

    users

kissfan4
Jun '16

seems like there is definatley an issue with the barrel, do you have a spare that you can try? If not i would contact the supplier, and or order some new ones.

lemonade
Jun '16

As a few of you have kindly confirmed that this is abnormal I’ve messaged the supplier. In the mean time I decided to take a thin file (which for some reason was supplied with the kit) and ‘adjust’ the inlet hole. It is now large enough for the filament to move better and I am now able to print, though the stepper is still not working completely smoothly, so will still look to get a replacement. For now I need to work on my calibration but thanks for the quick answers.

Perry_1
Jun '16

Your PTFE tube is too long, and is bending slightly when you put your nozzle on.

Your picture actually shows a slight bend in the PTFE tube, but even without the picture, when you described your issue, I knew immediately what the problem was. Your PTFE tube is too long.

Did you get a spare with one with it? If so, make sure it is shorter, and use it.

It needs to be straight, and sit just inside the nozzle when it is put on. If it is too long, it will not only not feed well, it will burn too quickly.