Feed issues, clicking and eventual grinding

[carrythewhat]

Hey forum! I've been having this issue since this Rostock Max has been under my guardianship, though it's been sometimes better and sometimes worse. I still am not sure what's the root cause.

The hot end has been upgraded to the E3D, but it's having quite regular feed issues. Once it is well calibrated, prints always start out smoothly. Good adhesion to the bed, and it gets the first many layers down fine. But eventually, the extruder motor starts to 'click'. Whenever it does this, the motor's knobbed bolt jumps backwards, and then continues trying to extrude. At first it is clicking backwards less than it's extruding forward, so the net result is still extrusion. If I give the filament a push, it will often overcome whatever the problem is and stop clicking for a bit. But the clicking eventually returns. If I do not do this manual fix, the clicking continues until it has grinded away pretty well the whole filament.

The previous owner advised me that he was having similar issues. He believed that there was too much or too little current going to the extruder motor.

I adjusted in the firmware was the current going to the extruder stepper motor. Too little, and the motor skips steps. Too much, and it grinds away the filament.

I have adjusted in the firmware both 'Extr. 1 PID drive max' and Extr. 1 PID max value [0-255]' to many values between about 150 and 255. In the past this did seem to help, but now it doesn't seem to make any difference.

The other possibility is there could be too much friction in the E3D hot end. I have attached some pictures.. whenever it seems to clog, there forms what seems to be a bulge where the filament feeds into the hot end. I'm not sure what is causing this or how to fix it.. I have now disassembled the E3D a few times and rebuilt it, but I'm not sure if I'm getting the torque-ing right.

I can't tell if this is a common problem or not, but it has been recurring constantly for the 3 months or so I have been using this printer. Does anyone else have a similar experience, or any advice that could help?

Thanks for your time!
Chris

[Eaglezsoar]

Does this happen with PLA, ABS or both? There is a good discussion going on at this topic: http://forum.seemecnc.com/viewtopic.php ... &start=620

[carrythewhat]

Thanks for your reply! I've only been using PLA on the rostock, since I don't have the heated bed set up yet.

So it looks like this is in fact a recurring problem with the E3D? Thanks for pointing me to this thread!

[Tinyhead]

^ Yup.

Lots of people experiencing the same problems. It seems to be very tempermental with PLA in particular. If you read the last 10-20 pages of that thread eagle mentioned, you'll get tons of info and near the end you'll see there's been somewhat of a breakthrough on the matter. The 'fix' looks promising at this point.

[carrythewhat]

Cool.. I see. So the 'fix' is at this point to machine out the nozzle in these ways? Or is E3D selling a 'fixed' nozzle?

[Eaglezsoar]

Cool.. I see. So the 'fix' is at this point to machine out the nozzle in these ways? Or is E3D selling a 'fixed' nozzle?

No fixed nozzle yet, but I bet they come out with them. MHackney found the cause of the E3D not printing PLA very well and now they will have to
do something. The problem is that you need a solution now. If you have a 2mm drill bit and a hand bit holder you can carefully remove some of the
nozzle as Michael explains but be sure of what you are doing before you mess up the nozzle for good.