Unable to remove the filament

Hi

Just connected my prusa i3 kit and tried my first ever 3dprint. It printed for just 30 seconds and then filament is not coming out of the nozzle.. printer just moving without creating object. The extruder motor pulley is rotating but the filament is not pushed inside. Then I tried with another new print... now filament not coming out of nozzle at all, but the extruder motor trying to insert the filament. So, I request help on two things:

1. Why the filament is not pulled into hot end
2. How can I pull out the filament.. I heated the hot end to 200 degree, loosen the clip of direct drive extruder and applied full force to take out the filament.. but it just not coming out. I felt more force may break something.. How can I pull out the filament which I inserted.

Below are my configuration:
Prusa i3, direct drive extruder, all metal hot end, .75mm nozzle. Using Repetier for printing

thanks in advance!

Hi,

the problem is extruder jamming. please heat the hot end 220-230C maybe little bit more. after that pull the filament with hand.


The problem is common, there is a lot of reason of jamming but the solution depends on the your extuder system. probably you don't have the thermal barrier in your extruder.. ( thermal barrier is inside the steel barrell, if you don't understand i can upload the photo)

ı think thermal barrier is the most important thing in extruder. trust me


please tell us more detail, your hot end degree, material vs. which type direct drive extruder do you use? has it spring?


after you tell us some detail, i believe we'll solve the problem.

---

Custom 3D Printer,

Mechanical Engineer

Thank you RDEng.

I used abs filament, extruder is direct drive with a spring in it. Please see the image here..
[www.3dprintronics.com]
The above came as part of DYI prusa i3 kit ( in mostly assembled state ).. which you can see here:
[www.3dprintronics.com]

I did the first test print with abs in 200 C that resulted in problem.

Below is what exactly happened:
I given my first ever test print.. nozzle extruded properly for 30 seconds approx.. and then it not extruding but printer acts like it keep the printing the object but without actually extruding ( is this called dry run? ). I noticed that even though the extruder motor & pulley is trying to push the filament inside the nozzle, the filament is not actually going inside the hotend. I suspect only the filament length which manually inserted inside the hotend only extruded and it never able to pull in the filament then on..

So, I cancelled the print and tried to start a new print ( same object ). But now there is no filament comes out of nozzle but printer is moving properly to create the object. I tried to insert the filament manually by pushing but it doesn't go inside. Even though the extruder motor/pulley is properly trying to push the filament inside the hotend, the filament just didn't go inside.

I decided to take the filament out, heated the hotend to 230 C and tried to pull out the filament forcebily but without success. I tried reverse movement of extruder motor through software, pushed the lever, gave full force to manually remove the filament... but not working out and feel more force may break something. Please let me know your thoughts.

Thanks a lot!

You cannot run ABS at 200c!
ABS needs to be at 230-240c. No wonder its jamming.

Hi Floyd,
Yes thats a mistake. Is there anyway I can remove the filament now. Standard method of heating the hotend to 230 to 240 C and pulling out the filament not working. Thanks

vlnthing,

first of all, please heat up the extruder about 250-260 C, wait for a whiile about 1-2 minutes. after that pull the filament hand or some tool. if it wont work, try to change your hot end. nozzle, steel barrell.

Perhaps your extruder will work good. Try it now and please tell us.

---

Custom 3D Printer,

Mechanical Engineer

Apologize for the delayed reply.

Before I see your reply.. As per the seller's suggestion, I removed the extruder motor, cut the filament before the barrel. And used a heated needle to manually clean the hotend. Now, I am trying again to do a test print, but noticed few things..

* Even though I manually set the template to 230 C in repetier, upon giving the print command, it first set the temp to 200, wait till the hotend temp to reduce and then start the print. Am I missing anything here.
* Also, the printer fan ( the fan controlled by firmware ) never seems running. Is this normal. Hotend fan running all the time as it should be.

Looking forward to your valueable advice. Thanks a lot !!

Edited 2 time(s). Last edit at 09/05/2014 01:21PM by vlnthing.

do you use ramps board in your printer?

"
Even though I manually set the template to 230 C in repetier, upon giving the print command, "



use set the temperature to 230C on repetier host. after that use send the print command? print what, a model?? if you print a model chek the slic3r temperature setting.

on repetier, if you set the temperature 230 C click the extrude than it will extrude. if you set 230 C on repetier after that you send the print command, your 230 C is invalid, slicer programs temperature is valid.

check that.

---

Custom 3D Printer,

Mechanical Engineer

The print temp comes from your Gcode file.
Its in the begining of the file.
Just change the 200 to 230-240 and try again.

Quote
RDEng
vlnthing,

first of all, please heat up the extruder about 250-260 C, wait for a whiile about 1-2 minutes. after that pull the filament hand or some tool. if it wont work, try to change your hot end. nozzle, steel barrell.

Perhaps your extruder will work good. Try it now and please tell us.

Thank you RDEng.

I finally managed to clean the hot end. Just opened the hotend, heated up a needle ( actually allen key, as needle don't take out any material but just pierce into the material inside )... upon inserting the heated allen key, materials forms a coating on it, and then pulling out the allen key also removes some material from the hotend. Clumsy process, needs to do till the new filament goes inside without any obstruction.

Quote
Floyd
The print temp comes from your Gcode file.
Its in the begining of the file.
Just change the 200 to 230-240 and try again.

Thank you Floyd. Very helpful.

I think the whole "I can't remove filament issue is due to SET HERETIC MODE poor design of the head/nozzle.

If the nozzle has a low pressure area or an area that would allow the melted filament to form a larger diameter in the lower part of the unit when cooled, it will be impossible to retract the material. Think of a barb on a hook or a knot on a string. If it freezes with a knot on the end, it locks the material in the chamber.

I worked thru the problem with my printer and a little time with my lathe to eliminate the larger area between the nozzle and the feed tube and it did wonders. I also edited the G code for the end of program to retract material 100mm as the head is moving away. If it doesn't freeze a non-retractable barb on the end of the material as it cools, it does not lock up.

Think of a funnel shaped material path, increased velocity as it goes thru, even an ice jam can be retracted out the top of a funnel, but not thru the bottom. Design rules, but methods can help work around a poor design.

Some of the issues with printing I see make me wonder who designed components and if they had a basic understanding of the intended use of said components. just sayin'.....

Ken