new hotend not extruding

[jccdesign]

nothing,starts extruding and then stops .

[jccdesign]

https://www.youtube.com/watch?v=kjDVEKo ... e=youtu.be this is a video of the problem

[Dale Reed]

jccdesign,

Hmmmmm. Here are a few things I'd try, not necessarily in any order.

1. Remove the fans and filament drive (black ABS printed part) (three screws) and clean all the bits of filament out of the drive gear.

2. Take a 1/16" / 1.5 mm drill bit and BY HAND (NOT using the drill) make sure the filament path through the drive is clean and clear.

3. See how much friction there is between the filament and the guide tubing. If there's a lot, try temporarily supporting the spool of filament directly above the printer and feeding without the guide tubing and see if that helps. (If it does, search the forum for "PTFE" -- some people have tried other PTFE ("Teflon") tubing for the guide tube, ordered from places like McMaster-Carr ( http://www.mcmaster.com/ online ). ) Also, the guide tubing can be smooshed out-of-round if it gets bent oddly or whatever and restrict the motion of the filament through it.

4. Check that the thermistor is properly located within the aluminum block of the hot end. If it pulls out a bit, you could be reading low and thus OVERHEATING the hot end. This could cause burnt/charred plastic to build up in the hot end (you mentioned brown), or could deform the PEEK insulator and/or PTFE insert within the PEEK insulator, causing distortion or restriction in the filament path right above the hot end. This would not explain the lack of motion in the video, since you have the hot end removed, but a clog here may have led to stripping out of the filament by the drive gear and accumulation of bits in the teeth of the drive gear, rendering it "not-drivey"...

Hope something here helps!!!

Dale

p.s.: New M2 word-of-the-day: "not-drivey".

[Capt. John]

Tension needs tightening where the teeth grip the filament.
Clue to my answer was the lack of teeth marks, or serrations in the filament from the drive gear.
One side of the filament will have teeth marks. Too tight and it squashes the filament,
too loose and it won't grip. This is one of the touchiest setting that has be be learned.

That and keeping the nozzle clean are the main issues I've ran into.

[jccdesign]

i have lossen the tension , all the ways possible, and nothing it just keep stopping, i think my problem is in that area , the filament guide , thats why i removed the hot end , because i can see plastic extruding when it is at operating temperature, and its brand new. Even with all the tension taken off , there is still something creating it.

https://www.youtube.com/watch?v=LBWrrHB ... e=youtu.be

[Capt. John]

That's just droll, my machine does the same thing.
Gravity and pressure builds up in the hot end and it runs out for a while.
Heated filament is more akin to a liquid, or it would never fuse together.

There's a couple of inches of filament in the barrel, forcing .175 filament down to the
tiny stock .35mm nozzle is not accomplished without stout pressure pushing it out.

Retraction settings that care of the when your printing.
Wipe setting at printing start up will knock the material off the nozzle most of the time.

[jccdesign]

its frustrating , i know it has to be something simple , but still cant find what the heck it is, tomorrow i might try holding the spool up and without the feeding tube and see if theres a difference. The problem is located before the hotend.

[jsc]

Have you taken off the filament drive as Dale suggested, by removing the fans and all the screws, and cleaning out the drive gear? That can get choked with stripped filament bits and will greatly reduce the bite.

[jccdesign]

yes , I've taken it apart , pass a small drill bit through by hand. played with the tension, , the gear doesn't seem to have any wear also. whats the recommended extruder speed?

[jimc]

Is the extruder clicking?