Ever since I have finished my 3d printer I have been printing terribley. You see all my prints have what looks like spider webs inside of them and my extruder keeps oozing all over the print. Today I learnt that it was an extruder calibration problem but that wasn't the only thing. I tried to calibrate it but no matter how many times I calibrated it it seems to always under extrude. Like everytime I change the M92 E variable it always under extrudes. The formula I am useing is (The wanted extruded length / The actual extruded length) * The current M92 E variable. I also tried setting a retraction but that made no difference. Can I have some help? Thank you.
From: Noah
UPDATE: 10/23/2015
Dear: LMR
Hello guys this is me Noah again. Just to let you know I know why my extruder can't get calibrated. The motor drivers are the a4988 pololu stepper motor drivers. They should have been something that can withstand more current because the mk8 extruder needs 2.5 amps while the a4988 motor driver can only with stand 1 amp. Also I am considering buying this motor driver because it is the only motor driver I know that can with stand around 2.2 amps. It needs thermal relief though and do you guys know any places you can buy thermal relief? I know that the motor driver and the sanguinololu my mother board is toasted because I accidently broke it trying to see if it was tuned or not. I will need to buy a new one. Also I know that the motor not getting enough current is the problem because I've tested to see if it was a problem and it was. Thank you and will this work?
Problem one: oozing: Does it ooze when extruder brought up to temperature, but still stationary? If yes, your hot end temperature is too hot, you might want to reduce it a couple degrees.
Problem two: underextruding: Did you have a look at your drive gear? There is a good chance that you have plastick stuck between teeth. If so, try cleaning in between teeth with some pointy tool and try to print again.
Sorry it took me so long to reply I was at school. Second of all I failed to mention the extruder is clicking softly. It is so soft you can barely here it. The only way I know this is that I feel it by touching the filament. Thank you it is underextruding and I will clean the teeth on my drive gear. Thank you they are very dirty.
have you calibrated the settings in firmware? and and the host, is the size of the filiment the same in both (measure the filiment it varies a lot)
cleaning the drive gear is not important(i never do it) but if they are full of plastic means they are slipping and grinding the filiment
check the tension. Run some filiment through with the hot end removed measure the length of the extruded material they must be the same check the extruded filiment you should see the teeth marks where the teeth bite in the material
the clicking maybe the motor shutting down make sure your feed speed is not to high
You should know I have calibrated the extruder several times and it doesn’t work. I have repeatedly tried unclogging my nozzle and nothing is clogged. The tension is fine I have spare springs for it. Also I have measured the extruded filament and it is always off by being under. Lastly the extruder gear is full of filament. Thank you.
I think Peter was right. You see I noticed there was a lot of filament on the drive gear and I removed that hoping it would fix the underextrusion problem but it didn’t. Now I am wondering if it might be a problem with the motor. It didn’t change a thing so can I get some help?
Noah, you had mentioned clicking in the extruder, is your drive gear properly fastened to motor shaft? Also I would make sure all wiring and connections from the board to the motor are ok. Also, as you mentioned, there could be a problem with motor itself. If you have an extra one, give it a shot. Keep us posted. isotope.
Honestly I think the motor shaft is on tight. I think that because I can’t take it off. I’ve done everything I could to take it off so I could clean it but I did clean it, I just couldn’t get it to budge. Honestly I haven’t checked the wiring. I know the wiring is right but I haven’t checked for loose connections and that will be my first priority. Unfortunatley I don’t have a spare nema17 but if I did I would use it but for now I don’t. Thank you.
You should use a fan to keep the stepper drivers cool I use 2 40mm fans, and fans on the stepper motors, my motor drivers came with heat sinks if you are going to buy new ones then pick the ones with heat sinks.
Dear: LMR Just to let you know I found out today I didn’t really short circuit my mother board. I am so sorry it took me so long to figure this out but I had other things in life to deal with. I tested the 3d printer without motor drivers and the printer worked fine. By fine I mean it turned on unlike before and it couldn’t print which was the same as before. Also I have a question, how can I test the motor drivers to see if they work? I have a feeling all or some of the motor drivers might work. I am using motor drivers a4988 pololu. Also I might need more motor drivers because I might have shorted out some or all of them. Help me please?
