Problem with the extruder "tube" [picture]

The filament gets stuck on the edge of the tube, as you can see. Has anyone else had this problem?

What do you think is the best solution?

Maybe sand the opening of the tube?

Edited 3 time(s). Last edit at 03/15/2015 10:38AM by filiptheking.

You need a new block. You may be able to flip it upside down, re-tap for the barrel and set screws.

It looks like you need better alignment between filament drive gear exit and the tube inlet. Was the extruder was designed for 3mm filament and you're using it for 1.75mm filament?

The arm isn't aligned with the gear, is too far down getting the filament out of track, reprint an arm and adjust it's length.

This image just shows all wrong things indeed, the opening should have been 1 or 2mm to the right. Is this a stock extruder that you got with the printer? Can it be you made a mistake assembling it?

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http://www.marinusdebeer.nl/

I have the exact same extruder on my printer, same yellow printed parts on mine too. I want to point out that the 2 bolts that hold the fan and heatsink on are not present in this picture and it seems the shift you are seeing is because of that. Having said that your extrusion gear does not look alligned, your filiment needs to be centdered on the gear, not at the edge of it. I am having issues with my extruder as well, always stripping, stops extruding and grinds the filiment, that yellow part that the spring pushes on that engages the bearing to push the filiment onto the extruder gear melted on mine and that let the bearing not push as hard as it should. I am currently looking for a better extruder head top replace mine, any suggestions? Wanty to print 100mm/s abs all the time.

I've had good results from my BullDog XL pushing 1.75mm ABS through an E3D V6 hot end.

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lunarkingdom
I have the exact same extruder on my printer, same yellow printed parts on mine too. I want to point out that the 2 bolts that hold the fan and heatsink on are not present in this picture and it seems the shift you are seeing is because of that. Having said that your extrusion gear does not look alligned, your filiment needs to be centdered on the gear, not at the edge of it. I am having issues with my extruder as well, always stripping, stops extruding and grinds the filiment, that yellow part that the spring pushes on that engages the bearing to push the filiment onto the extruder gear melted on mine and that let the bearing not push as hard as it should. I am currently looking for a better extruder head top replace mine, any suggestions? Wanty to print 100mm/s abs all the time.

It's true that he bolts are missing. I'm sorry for the first picture, it was missleading, but at least you can see that it is on the top of the tube that it grinds the filament. I will try to sand it a little bit, I'm pretty sure that it will work.
I don't think there is any big problems with the alignment.. here is a proper picture with the bolts in:

Edited 3 time(s). Last edit at 03/16/2015 05:33AM by filiptheking.

A countersink can help taper the inside to prevent sharp edges from scraping the filament. Don't go too deep. Just the slightest bit. If you don't have a countersink, a large drill bit can have the same chamfering effect.

fliptheking, I am an engineer by trade and all I can say is I can not wait to try my bulldog xl, so many lost hours trying to diagnose the same extruder, changed stepper motors, calibrated, changed current, changed slic3r, pulled some hair out. I will update if the bulldog works better.

Wanted to add I have changed hotend tubes, I even learned how to rebuild them by replacing the ptfe inside them but I have 5 extra tubes, 5 extra nozzles and another complete hotend all brand new and they do nothing to make the chewing of the filament any better. I have tried every setting applicable in slic3r, have calibrated my current for my stepper motor, nothing. I feel this is a substandard design that is hit or miss on printing reliably.

Edited 1 time(s). Last edit at 03/16/2015 06:21PM by lunarkingdom.

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lunarkingdom
Wanted to add I have changed hotend tubes, I even learned how to rebuild them by replacing the ptfe inside them but I have 5 extra tubes, 5 extra nozzles and another complete hotend all brand new and they do nothing to make the chewing of the filament any better. I have tried every setting applicable in slic3r, have calibrated my current for my stepper motor, nothing. I feel this is a substandard design that is hit or miss on printing reliably.

That does not sound very promising! I've had som problems with i while. Yes, please update of the bulldog works better!

OK here is my update, I spent some time getting the wiring right but if you go this route I can get you on the right track. I made a custom mount out of some aluminum sheet I had lying around and a couple drill bits, mounted it up with the same style tube/heater block/nozzle I was using on the direct drive, leveled the bed and tried to print. I had to change the value of the extruder from 95 to 495 in the settings (I will link my thread in another post below this one) and let her rip. It extruded my crappy older clear abs no problem after turning up the current a little, I am having a blobby stream but I have 3 or 4 E3D hot ends coming and have yet to tweak the settings BUT the bulldog XL pushed the filament out with no problems whatsoever, I was a little worried since it cost 160-170 shipped but I am happy to report I do not believe I will be facing an "extruding" issue again, now I can focus on the tune up and get back to design work and printing again. Totally worth the money!!!!

[forums.reprap.org]

Felt so good to toss that old extruder in the spares drawer!!!

Looking forward to tuning up and using my bulldog xl!!!

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lunarkingdom
[forums.reprap.org]

Felt so good to toss that old extruder in the spares drawer!!!

Looking forward to tuning up and using my bulldog xl!!!

Sounds really good! Maybe I will buy that if i get more porblems. I solved the problem with the filament getting stuck by the way, just sanded it a bit. But there is still a problem, in the begining of a print, it looks like it has a hard time pushing the filament out. But after a while, it comes out as it should... what could be wrong?

It's probably just ooze bane. When your previous print finishes, while the hot end is still hot, the plastic will ooze out leaving empty space inside the hot end. This will take time to fill at the start of the print. This is why a perimeter is added to the start of a print. To "prime" the nozzle.

Unless your temperature readings are not working properly. Then it may not be melting your plastic fast enough.

One thing I am learning is with the short hot end you really do not have much heat control, with an E3D style hot end you can cool it much better but you might loose a couple inches of your up travel for using it. Check your temp settings for ABS I use around 245c. You can add to your skirt in slic3r so it does 2 or even 3 passes (or was that brim I forget) before starting the part that way it can even out before your printing the final product.