PLA Jam

[AndreaBignozzi]

Hi all,
I'm calibrating a G2S pro, and 'm having some problem with PLA extrusion.
I'm not able to extrude filament for more than a few seconds, after that the extruder stops, and I have to force out the filament, and starting again.

I've tried extrusion from 170° to 230° in steps of 5° with and without the extruder fan, without any particular difference.
At 170° I have the low part of the J-extruder (attached to the hot end block) that is at 130° and the top end at 40°, with speeds from 0.5 to 2 mm/s.

I'm not sure if the problem is the motor that cough because has not enough torque or because the jam, or the fan the is not able to lower the extruder leg.

I'have checked the A4988, setting Vref at 1.7Volt (maximum allowed by the trimmer), that with the Rs=0,2ohm gives a max current of I=Vref/8*rf=1A well below the 1.6A rated in the extruder mother specs.

If I use ABS from 230° to 260° the extrusion is a bit slow, cough if speed is more the 1 mm/s, but continuous...

Any suggestion?

Regards

[James Zou]

Hi,friend.For this issue,you can refer to this Link: http://www.geeetech.com/forum/viewtopic ... 13&t=17097

[AndreaBignozzi]

Thanks for the quick reply, but I've already followed all the suggestion in the posts, and the ones in many others without solving the problem.

Can you tell me the expected temperature, at the base and at the top of the screw bar (with the PTFE inside) when the hot end is at 180° (PLA) so I can check if my fan if big enough?

I suspect the problem is too few torque on the motor, because with my small nozzles (0.3) also the ABS extrusion is very slow, no more then 1mm/s, when in your document you suggest a 2mm/s speed. I've already pushed the driver at his maximum (Vref=1.7 => Imax=1.06A), that solved the problem with ABS, but not with the PLA...

Regards