Extruder "stuttering" when printing raft


#41

Yeah, I agree with both of you guys. Once I do a cleaning, I will take some video and report back. 

Come on, Julia is a nice lady (and sophisticated engineer), I am just a guy...


#42

I'm also "obstinate" as reported in the last post of this thread :)

https://craftunique.com/forums/view-thread/941


#43

Julia has been especially helpful!  :) As have you Z-Renegade! Thank you to you both, girl and guy respectively  :)

I will report back soon!


#44

Based on your descriptions I can also state, that it is clicking what I mean. For my understanding there is something blocking the further way to the nozzle. The strange thing is, that it also happened directly after assembling the cleaned hotend and nozzle.


#45

Come on, Julia is a nice lady (and sophisticated engineer), I am just a guy...

I will find out, when I finally receive my Z-Temp after it passed the custom clearance. I’m already pretty excited looking forward to the first test prints. :slight_smile:


#46

Based on your descriptions I can also state, that it is clicking what I mean. For my understanding there is something blocking the further way to the nozzle. The strange thing is, that it also happened directly after assembling the cleaned hotend and nozzle.

If the nozzle is free, then either there is still some blocking in the feeding tube (I had this after using a 'very dangerous filament') or the nozzle is not heated enough, again several possible causes for that.

You could get after it if you just remove the nozzle and extruder motor and try to push filament manually thru the tube.

If you get that 'clean', try again with the nozzle installed. Finally with the motor (after ensuring clean gear).

The hotend can be heated in the firmware menu (cannot tell exactly, have not seen the printer for a while).  :ph34r:


#47

Yes, that’s why I cleaned the nozzle and the whole hotend with the feeding tube. There was nothing remaining. I was able to push the filament by hand and it came out of the nozzle, so everything seemed fine.

Is it also possible, that the hotend is too hot and cloggs while printing?

Strange behaviour of this machine. :wink:

But I will try the steps you adviced before I try to print the model with z-hips again.


#48

OK, here is a video of what I would call "clicking", "skipping", or "stuttering", interchangeably. The filament exit is blocked at the nozzle.

The gear looks like it's rotating continuously, but this is an illusion, as can be clearly seen by looking at the flat on the shaft.

The filament is going up and down before the entry.

My interpretation is that the magnetic force in the motor is unable to overcome the resistance of the plastic in the blocked nozzle, so the filament acts as a spring and the stored energy in the compressed filament pushes the motor backwards at the point in the stepper winding control sequence where the torque is lowest.

https://youtu.be/uk2MYzIQFAo


#49

Yes, that's why I cleaned the nozzle and the whole hotend with the feeding tube. There was nothing remaining. I was able to push the filament by hand and it came out of the nozzle, so everything seemed fine.

Is it also possible, that the hotend is too hot and cloggs while printing?

Strange behaviour of this machine. :wink:

If the hotend is too hot you can tell from what's extruded (while printing or when cleaning) burned filament looks like that (burned).

Maybe it's a defective ribbon cable that causes temporary outages of the heating (had this also before).


#50

My interpretation is that the magnetic force in the motor is unable to overcome the resistance of the plastic in the blocked nozzle, so the filament acts as a spring and the stored energy in the compressed filament pushes the motor backwards at the point in the stepper winding control sequence where the torque is lowest.

This is the engineers perfect description of what I was trying to describer earlier.  :)

And I call it clicking, maybe skipping and still have the opinion that stuttering is that what I explained before.

That's because I am obstinate too and because you gave the explanation to it:

All-tough it's an illusion that's the difference: While clicking you can 'see' the gear moving continuously forward, when stuttering you can see it clearly moving right - left - right - left...


#51

@Julia: This is, what the printer is doing. But it is not doing this continously, but randomly. It’s clicking some times, then extruding properly, then clicking again… Like a partial clogged filament tube or something like that.

@Z-Renegade: What you said sounds also plausible. I can remember some months ago, the printer probably had a problem with the cable. When switching on, it said something like check the printer or cable and restart again. But this happened only twice and since then it printed properly.

Thank you both for your help!


#52

"You have Ztemp on the machine, that is why it is not working right" -someone somewhere probably.

With all the machines I work with this problem is by far one of the worst to try and figure out over the phone or email. There are so many possibility's and it is always the one that gets overlooked.


#53

@Renegade: OK, the confusion was when you said "loses its grip on the filament". By this I thought you meant that the toothed wheel/gear was actually slipping (no grip) on the filament. I don't think that that's happening; I think the gear is gripping the filament very strongly and not slipping at all - it's the magnetic field "losing its grip" on the rotor of the motor.


#54

@Z-Renegade: What you said sounds also plausible. I can remember some months ago, the printer probably had a problem with the cable. When switching on, it said something like check the printer or cable and restart again. But this happened only twice and since then it printed properly.

Yes, this is a cable issue, could also result if the connectors are not fitted firmly (and of course if a ribbon cable that looses contact at the connector when bended).

To be sure what we are talking about: You are using a Z-Filament (and not Z-Glass) with the corresponding sliced profile?


#55

"You have Ztemp on the machine, that is why it is not working right" -someone somewhere probably.

Thanks, Michael, for bringing that up - very helpful  :P


#56

@Renegade: OK, the confusion was when you said "loses its grip on the filament". By this I thought you meant that the toothed wheel/gear was actually slipping (no grip) on the filament. I don't think that that's happening; I think the gear is gripping the filament very strongly and not slipping at all - it's the magnetic field "losing its grip" on the rotor of the motor.

It's foreign language to me and I am no engineer.  :ph34r:


#57

@Julia: This is, what the printer is doing. But it is not doing this continously, but randomly. It's clicking some times, then extruding properly, then clicking again... Like a partial clogged filament tube or something like that.

I think you said you've cleaned the nozzle, but have you actually tried a brand new one?

And it could be a temperature thing, maybe the hot end is just not getting up to where it needs to be.


#58

It's foreign language to me and I am no engineer.  :ph34r:

Your English is infinitely better than my (zero) German, I'm not criticising, just clarifying :)


#59

Thanks, Michael, for bringing that up - very helpful  :P

Maybe he's trying to get the warning points balance in the family?  :ph34r:


#60

Your English is infinitely better than my (zero) German, I'm not criticising, just clarifying :)

Come on, you can write and spell your german name correctly, that's not zero.

And your'e clarifying is always helpful.