Printer not printing (Extruder?)

Hi

After getting around the driver installation problem I was finally setup to print. So I downloaded a relatively simple model and begun printing. However, the printer moved as thought it was printing but nothing happened

After an hour of messing about with it, I got two blobs of PLA come out of the extruder but nothing else, deeming the printer an expensive noise maker

I think the extruder may be blocked but I haven't got a clue on how to fix it and how to prevent it from happening going forward. I've roughly measures the PLA that I insert and it seems to almost be completing the way through the extruder but it just isn't getting through the last centimeter or so. I'm unclear on how far it does actually need to go through

Anyway, does anyone have any ideas how to fix this?

 

Hi

Is the extruder motor turning?

 

Hi,

Yeah, but it wasn't feeding any PLA through. I think it is blocked and have taken off the Extruder but need some tools to unclear the blockage as per the video on YouTube. However, do you have any other ideas as to the problem?

 

if the hot end temperature is right, then it should melt wenn you push the filament down (or if it gets pushed down by the hobbed-bolt)
so the hot end seems to be clogged

i dont have any other idea

 

or maybe the pressure from on the hobbed bolt is not high enough, so you have to push the filament more against it

or the filament is not on the right place

 

While the hot-end is up to temperature (185-200 for PLA), can you manually push the filament through the extruder hole (aka bypassing the motor). When you do this you should get plastic coming out of the hot-end.

Make sure you've raised the Z height by like 20mm when you do this. If the hot-end is resting against the bed, it'll be blocked and nothing will be able to come out. By making sure the hot-end is above the bed with empty air underneath you know then that the bed isn't blocking.

If you can manually push filament through and get plastic out of the hot-end then you know there is no blockage internally.

If you cannot do this you may be a block inside the extruder or hot-end. Take a look at Robo 3D/s video on disassembly of the extruder. You could have a cracked PTFE tube or other issue.

 

How can I go about getting a new PTFE Tube? Whilst I haven't looked yet, I am fully expecting that the tube is clogged with PLA

 

I've now just wasted the sixth hour of my life on trying to fix this. Below is what I've done so far

1. Checked the hot-end for any cloggage by trying to push a needle through it. It hardly goes in
2. Taken the entire tube off of the motor part of the printer, heated the hot-end to 190 and fed PLA into it. A stream of PLA came oozing out of the top in a hollow type cylinder shape. I then pulled this out after cooling to no avail - still blocked
3. Heated the Hot-end up again and checked in side. No more PLA is being fed into it (not melting) as I was attempting to melt the PLA to the already melted PLA to pull it out... didn't work
4. Obtained a footpump and put the adapter on the end in an attempt to create a pressure to force the hot PLA (heated to 190) through the hot-end. Did not work


So I have no idea where to go. The instructions in this video have been followed and still its knackered

When I push a paper clip into the top of the cool hotend, it stops going down just at the bottom of the initial set of safety tape

 

Those steps you described give me a lot of concerns that you might have done more harm than good.


Have you not been able to remove the ptfe tube? You can email team robo and they'll mail you replacements if yours is damaged.

 

I had the filament shaving problem and it's because the temperature is too low. Fortunately, I have a Flir thermal imaging camera. I checked the nozzle temperature and found it to be 20C below the setting. I set the first layer temp to 240 and others to 230, which is actually 220/210 and all my problems went away. I also slowed the print speed dramatically, will have to try speeding it up now.

Robo needs to invest in a thermal camera and calibrate their sensors. As an EE, I know part tolerances add up! -5% plus -5% = -10%!
Also, the heated bed is a lot hotter by its connector. Thermal imager shows a weird looking pattern. Could send imager photos?

 

I would be interested in seeing the bed thermal image.

 

Here's the Flir thermal imaging report on another thread:

http://forums.robo3dprinter.com/index.php?threads/filament-stops-extruding.1267/#post-13480