Budaschnozzle 2.0 PLA Fix

As some of you may be aware, we’ve been looking into the reports that some Budaschnozzle 2.0 users have been encountering issues when printing with PLA, such as pooling on top of the heater block. Thank you for your help and patience while we looked into resolving this. We have three tested solutions. You will want to choose one based on how often you expect to change nozzles. More information can be found here: https://www.lulzbot.com/?q=support/budaschnozzle-20-pla-solution. Thank you again!

Why does using PTFE tape on the nozzle threads make it permanent? I ask because I JUST did that last night - the PFTE tape has no adhesive on it, so I’m not sure what makes it permanent.



I too, was wondering the same thing.

Antony (has an AO-101, but just ordered a Buda v2 and extra nozzles for it)

someone suggested running ABS thru the nozzle first, to help seal it up…then use PLA. Does that work?
I have not tried PLA yet, but have been printing plenty of ABS and nylon.

And wasn’t there an out-gassing issue with getting PTFE too hot. seems like the tape will be getting VERY hot.

When we tested the PTFE tape on the threads for the nozzle we found that they would bind and made removal rather difficult.

I carefully grip the heater block with a pair of channel-lock pliers before I try to remove the nozzle and I haven’t noticed any difficulty.

I’ve finally gotten all my “derps” fixed with my TAZ and I’m going to be running it hard for the next few days. I’ll let you know how the ptfe at the nozzle works out. :slight_smile:


I’m now only printing with pla. If i choose one of the tree solution will i have any problem if i decide to print abs?

Do you know a method to clean well the scrap pla that deposited all around the threads and the heater block?

When I cleaned mine off, I brought it up to temperature and used a cotton swab to grab all the plastic out of the threads. It worked very well.

The teflon tape on the nozzle works great - zero leaks in about 10 hours of printing so far.


Why is this not done to the heater block right off the bat!!!

after using my new hot end, for a week now after finally hooking it all up, I notice that the extra material dripping down my barrel is actually a problem and a known problem at that.
so after reading through the forum I find this solution, however;
my heater block will not detach from the threaded rod.
it is at 160 C, I have also tried at 185 C

why was this problem not discovered before it was released to the public?

make a picture depicting the heater block set screw!!! and label in RED

In our testing of the Budaschnozzle 2.0 hot end we did not see the problems with PLA. Due to a number of users seeing the issue we presented fixes if they are seeing problems with PLA.

I would recommend retrying at 160C and moving it little by little, back and forth, you’ll also want to make sure that the heater block set screw is loosened. If the heater block still cannot be moved and you cannot use any of the suggestions you can send an email to support@LulzBot.com to start the exchange process.

Because of the low viscosity of PLA at extrusion temperatures it can flow through the nozzle threads and upwards out of the top of the heater block

The recommended PLA fixes have not worked in my case. The PLA is leaking from the top, where the all thread meets the heat sink ceramic-like female fitting.

I used option 3 (teflon on the nozzle threads) before using the printer. Without delay PLA began pooling on top of the heater block, then oozing onto the nozzle and ruining prints.

I removed the nozzle, saw no evidence of PLA on the nozzle threads, but I have been printing with white and maybe I can’t see it. After everything was cleaned, teflon applied in multiple layers to the nozzle threads, I reassembled the hot end and reloaded the filament, this time in neon green.

Sure enough, PLA began pooling on the heater block, no evidence of green on the nozzle threads. After removing the all thread from the heat sink I could see the source of the leak, which has been coming down onto the heater block from the heat sink, not from the nozzle threads upwards.

The female heat sink end is gunked with PLA. I cleaned the all thread and tried using teflon tape to seal this connection but the ceramic- like female end just spins in place and I’m afraid of torquing down on this connection and breaking something.

Any suggestions? In my opinion this PLA design/testing/assembly flaw should be grounds for a hot end recall. This really goes beyond a modification or simple fix.


The hot end should not be getting hot enough to allow the PLA filament to get hot enough to melt that far up above the nozzle. Are you using a fan when printing with PLA? PLA will hold onto heat remarkably well, it’s known as heat creep. The heat from the nozzle will actually travel up the PLA filament. It can lead to jamming if the molten filament cools and sets above the melting chamber. A guide to installing a fan onto your printer can be found here: https://www.lulzbot.com/support/3d-printing-pla-plastic-filament If you have any other questions you can always send an email to support@lulzbot.com.

Agreed, the hot end should not be allowing heat creep, but it does.

Yes, in fact I installed two fans; one always on directed at the heat sink, and another directed at the print controlled by slicer. With this setup I completed a seven hour print without jamming. Without the fans the extruder would jam around hour two or three.

I see nothing to stop the entire length of all thread from heating to extrusion temp and leaking where it connects to the heat sink. I will try Teflon tape, then liquid thread sealant to stop the leaking.

update: Teflon applied to allthread ABOVE the heater block stopped the leaking.

Which fan mount did you end up using? Would you mind sharing the model?

Sure, the fan mount I designed is attached, notes:

-The 45 degree orientation of the heat sink fan (top) is not ideal; some air blows onto the heater block.

-The print fan (bottom) could probably benefit from a duct, the hot end gradually loses heat and can’t maintain temp.

-The chicken and egg irony of printing a pla cooling fan mount in pla. Because the mount contains a long 45 degree overhang my prints repeatedly failed until I wired and hand held the fan with support turned on.

-All my holes required reaming to fit the hardware

EDIT: improved mount design with duct “FANmount2_wDuct.stl” fixes the above problems
FANmount2_wDuct.stl (1.1 MB)
FANmount2.stl (814 KB)

This is a terribly designed piece.
once any plastic gets on it your screwed.
my thermistor failed attempting to fix leak.
and once the thermistor fails you cannot repair it.

the wiring is crimped together, this is garbage.
impossible to replace or fix without drilling and using pliers on the wiring.
using alligator clips would be much better.

Has anyone thought of or tried a Teflon washer to seal off the nozzle? I thought of machining an oring groove in the nozzle and then using a silicone or Kalrez oring to seal it off.

Update. I just made a Teflon washer and that fixed the drip.

Check if your nozzle really is tight before your first print, I just started using my spare and I could tighten it 20 deg without problems. And I have no problems with PLA leaking at this point. No tape or anything.


I print with PLA at 206C and have no problems with good fusion in my layers, heater block pooling does occur as it seems, it drips down over my models when printing longer than 3 hours, I suggest simply cleaning this little pool with a Q-tip which absorbs the PLA nicely (when the tip is hot) and then doesn’t let it drip down on my models while printing. When I tried printing at lower temps it seemed to not work/extrude as well. I had to mess with the speeds a bit to get the retraction, and varied speeds correct, but now I can reliably print without worry of model print failures, as long as I make my 3-d models printer friendly and wipe up the ooze from the extruder while it prints before it drips down on my models.

Had a lot of PLA leakage above the heater block on a Budaschnozzle 2.0 and replaced it with a Budaschnozzle 2.0c as I needed to rebuild the old one and was told the ‘c’ version fixed the leakage. Well, it didn’t and I still have some pooling on the heater block. I’m going to try printing out a cooling nozzle found here https://forum.lulzbot.com/t/improved-taz-fan-duct/658/1 and see how it goes.

Isn’t it about time for an all metal extruder path that can handle higher temps? It’ll require some active cooling but that’s not that much of an issue.