Taz 5 Extruder issue.

Issue:

Hello LulzBot community! I have been having an issue getting my lulzbot to properly extrude and I’m not sure what to do. To begin, I have already soaked the nozzle in acetone for 2 days. I have fed wire through the nozzle to clean out anything that could possibly be clogging it, and I’m using Lulzbot PLA just to be safe.

I start hand feeding PLA(Or any plastic) through the nozzle and it feeds fine. When I switch over to the hobble gear feeding I get issues with no feed and the gear chews a spot out of the plastic. On the other hand, if I feed the plastic through by hand, tell the software to start rotating the gear, and then apply the tension bolts, it will feed continuously until I pause the gear for a couple seconds. I think the video below will help you all see what I am dealing with.

Video:
https://www.youtube.com/watch?v=wqapYCOvLFA

A couple things I see right off the bat. Your springs on the idler arm look way too loose. You want 8mm or less between the two washers on either side of the spring. You should also double check that the squirrel cage fan is running constantly. It looks like the upper barrel is getting too warm if you are getting deformation that far up, which could be causing bore lock expansion due to heat creep up the filament.

Thanks for the quick reply, it doesn’t seem like the squirrel cage fans ever comes on. Any ideas why? As for then tensioner screws on the idler arm, I took them to both extremes, very tight and very loose. I usually keep them at 5mm.

I would contact support, the fan on the body of the extruder should run as soon as the printer powers on.

If you can’t clear a nozzle with cold pulls and you are running PLA, you can soak it in Scigrip 4 to dissolve the PLA. I have not had ANY luck dissolving PLA with anything else. Scigrip 4 is to PLA what acetone is to ABS. Use gloves and ventilation, it contains nastyness.

I just drop my nozzles right in the can with tweezers and let them soak at room temp for several hours.

http://www.amazon.com/SCIGRIP-Acrylic-Solvent-Water-thin-Screw-On/dp/B000KZUTEM

If the little extruder cooling fan is not running that is the problem. Did you contact support and what did they say?

I’m having the exact same issue. My little fan that says AIR on the side of it that points at the cooling fins is running. The larger fan that points at the tip of the extruder is not. This problem started a little while ago so while i was taking the time to clean it I installed my flex dually. I had no issues with it what so ever. Immeidately after switching back to the .035 hexagon the issue came back. I did re-insall the default firmware. E-Steps may or may not be off but I can’t calibrate them because I can get the filament to feed thru properly. It’s starts, goes for a bit and them seems to just chew up the filament. Note however, even when it not feeding there is still filament coming out. Somewhere between an ooze and extrusion. it does appear that if I continue to extrude it may pick up and extrude normally for 30-50 mm then pauses again.

Forgot to state. I started with ABS but have been trying with cleaning filament the last few attempts.

Thank you for the suggestion, added that to my amazon cart and will purchase it when I buy more stuff.

I contacted support and they told me I need to switch out the fan first and move on from there. I attempted to power the fan with an external 5v supply but it wouldn’t move at all so it must be dead. I will update once I get the new fan in.


If it’s the same issue that I’m having then maybe your little small fan is cooling that feed chamber enough. When you pull it out is that top area very malleable and squishy?

I have never used cleaning filament in the six months I have owned 3D printers? Neither one of my TAZ printers were prone to jamming.
That small squirrel cage blower TAZ uses for hot end cooling has been a problem in the past. My MakerGear M2, the current printer I use nearly everyday, has standard mini 12/24 volt fans. The heated nozzle is isolated from the filament feed, so really some users are not using the extruder cooling fan at all. The only jams I have had with this printer is spooling ones, where I forgot to make sure it was un-tangled before leaving a long print to run.

No one from tech support has directly commented or issue any statement about this ,however I emailed support to inquire about the .35 mm nozzle missing from the parts store. I was told they are no longer selling the .35 because of issues with the nozzles getting clogged. I went to the website and sure enough, the TAZ 5 is only offered with .5 mm nozzle. Between my earlier posting and this one I purchased a replacement extruder body. Not just the nozzle as they were not selling it, but the nozzle, heater block and cooling fin. Replaced mine with it. The motors, fans, etc all my existing ones.

My issue with eating the filament is gone. It would appear the issue was my nozzle. I did order a nozzle from matter hackers and will try to put in on my old heater block and fin when it comes in and see what happens.

I have just had a look at the tech drawings (attached) and notice that the internals of the Budaschnozzle V2 nozzle, and the Hexagon nozzle are essentially the same, with the exception that the discharge tube below the internal taper is 3 times as long in the Hexagon at 1.5mm vs the Buda at 0.5mm.

This must surely have an impact on the force required to extrude and is the probable reason the tensioner needs to be tightened so much more on the Hexagon. It is in fact quite noticeable when pushing filament through the nozzle by hand. I could quite easily extrude with hand pressure on the Buda whereas it is very difficult with the Hexagon.

Additionally, this may also adversely impact the retraction on the Hexagon.

I wonder if there is a technical reason for the increased discharge distance.

Cheers

Sam

TAZ is not the only manufacture using the Hexagon hot end. Check on eBay I think you will find some .35 nozzles listed and complete hot ends if needed.