Budaschnozzle clogging mid print. (SOLVED)

Hi everyone in the reprap community. I have built a prusa I2 using NEMA 17s, I have also chosen to use a Wades extruder along with the Budaschnozzle 1.2 with a .35mm tip from Lulzbot. First let me say that I have read some of the other topics. But I would rather have more of a personal response to my specific problem.

First things first. The hot end mid print if not sooner jams up and becomes clogged. I am currently printing Atomic Green 3mm PLA at 205C at 40mm/s at .28 layer height. This under normal situations works great, but I see a flaw when I print tiny bits, and it becomes clogged. When I pull out the filament after it is clogged it appears as if it is not being pushed through the tip fast enough. So I checked the tension on my idler, and even checked my hobbed bolt to make sure it was free of debris and such. Check. That was good. So I also read about the hot end needing additional cooling around the copper "heat sink" towards the top of the unit. Seeing that it had a upwards facing copper bowl kinda had me weary in the first place, but for $99 asking price I didnt question it till now. I agree with previous post that the hot end is not properly cooled from the get go and the need for additional cooling should help my situation.

I plan on designing a fan duct to match my setup to vent cool air to this and see if that help. But currently I am having to sit next to my machine and have my eyes never leave the print in fear of when* it will fail. This is becoming increasingly frustrating when I am trying to print out parts to remedy my problem. I am sure I am not alone in that last statement either.

Future plans for my printer are going to be switching to a bowden extruder arrangement to get some more space between the hot end and the extruder itself which i believe at the temp I am running has some effect with my issue. To add, I have lowered the temperature but that clogs it faster. And I have also ran it faster, but with multiple failed attempts in most cases.

Any one else suggest something else? I would love to hear more.

Thanks,
Nate

I have also included a picture of 2 examples of filament after it clogs mid print.

Edited 1 time(s). Last edit at 01/19/2013 12:32PM by ncl32.

If you're printing PLA, you really need a fan even on a buddaschnozzle, doesn't have to be anything fancy or ducted, just needs to move some air past the thermal break.
PLA gets soft before it melts and as the heat creeps up the thermal break it becomes harder and harder to extrude, eventually it mushrooms inside the PTFE liner, and you get a complete jam.

Ditto, need a fan on that thing. I had the same issues with PLA. The heat takes a while to creep up into the filament which allows it to soften and expand within the aluminum threaded cylinder/PEEK isolator. Once I added a fan, all was good.

Good to know guys. I will be trying this out and reporting back on my hopeful accomplishments.

I would also like to just say that it is such a piece of mind knowing that the RepRap and 3d printing community in general are very supportive and welcoming.

Thank again guys,
Nate

Well I would like to report that all is well, and I am now printing with 100% success. The fan was the game changer with printing with PLA. I should have know this but through all the excitment of wanting to print out my designs that have been waiting for years, I seemed to have completely bypassed the solution to my problems. But that is what the community is great for.

Thanks for everyones help,

Nate