Lulzbot Tax 5 grinding all filaments and not extruding

I have a problem that makes me want to sell my taz 5. About a week ago I left home during a 11 hour print. When I get back the spoil of filament has finished with about 40 mins to go and had been extruding nothing for that time. I didn’t think anything of it and went ahead and ordered some new filament. When the new filament arrived, it started grinding it. I changed back to some filament I’ve used before and that grinds too. ABS was also grinding.

It’s not heat creep because I’ve solved that issue. I’ve changed idler settings, temps, taken apart the whole extruder to no avail.

I even went ahead and bought a whole new hot end (0.35mm) and the same thing happens. I’m absolutely lost. I need some help please. Lulzbot are terrible with support especially for those of us who don’t live in USA. I can’t even send my printer for repair. Does anyone know what might have happened? Is it a heating issue? Although the temps are constant on the display.

I seem to be able to extrude in the air 7 times out of 10 but when I start print, it just grinds the filament. It almost seems like the filament moves left and right whilst the gear is pulling it.

Please help guys I’m in deathly need of it.

What extruder/hotend are you running?

I’m a bit concerned when you say

I seem to be able to extrude in the air 7 times out of 10

You should always be able to extrude in the air to make sure the filament is flowing.

While I normally tend to think of things like clogged nozzles, bad idler arm tension, or hot-end not heating up enough to melt the material. But you mentioned replacing the hot end and you mentioned a 0.35mm nozzle … and this tripped a few red flags (You can do this… but you have to update settings and if you do not update settings, it will cause problems. And since you are having problems… I’m wondering if you missed those steps.)

The TAZ 5 probably would have come with a Hexagon hot-end and a 0.5mm extruder nozzle.

If you swapped it for a 0.35mm nozzle, then you have to update the firmware and software to match. Did you do that?

Otherwise the printer thinks it has a 0.5mm nozzle and is trying to push filament through MUCH too fast. The opening on a 0.35mm nozzle is roughly 1/2 the area of a 0.5mm nozzle. (Skipping the full version of the math … whenever the diameter changes by a factor of the square root of 2 then the area is either halved or doubled … depending on which way you were going). The square root of 2 is roughly 1.41. So if you divide .5 by 1.41 you get .354 (close enough).

The simplified version is… if you did not update your settings, then the printer is trying to force the filament through the hot-end twice as fast as it should.

Hi, thanks for your detailed response. I’m using the stock extruder with a new nozzle.

This issue was being caused last week whilst the 0.5mm nozzle was on the printer. I thought I had a super clogged nozzle which is why I bought the new nozzle.

When the filament grinds, I just snip off the end and reinsert it into the nozzle with the tool tip in the air. Sometimes it grinds right away and others it waits until I press print and grinds as soon as the print starts.

Once I put the new nozzle on I changed both nozzle size diameter settings and also updated the relevant print settings (line width etc, since lulzbot Cura doesn’t update these dynamically)

I can make a video for you guys if you want? Showing what happens

Video would be helpful.

Can you clarify… did you buy one of these?

Or is it just the extruder nozzle that you replaced?

If you replaced the entire hot-end, then it’s doubtful there would be a jam left anywhere (which is why I wondered that maybe the extrusion rate was too fast for the smaller nozzle).

If you replaced only the nozzle, then maybe it’s possible that there is some jam in the hot-end … or even up in the cold-end (above the “heat brake” gap between the hot and cold sides of the system).

Yes that is exactly what I purchased. I’m absolutely stumped. Please help )))):

i will grab a video for you guys tonight when i get home from work. im super bummed about this, im not sure why this is happening </3

If it extrudes in the air but not on the bed, it could be that the bed offset is wrong and the print head is laying directly on the bed which does not allow filament to extrude. For fun you might want to go through the bed leveling procedure or for a quick test, just turn the zeroing screw so that it thinks zero is a few millimeters above the bed and see if it becomes magically delicious

I’ve had trouble with our Taz-5 at the Creator Hub were I maintain the printers in that the X carriage gets out of level such that it is nice and zeroed on the left but off a few mm on the right. In my case it is up in the right but in your case it could be down which leaves no gap between the nozzle and the bed so no filament comes out

It is best to search or read your manual for the bed leveling procedure and follow that before ripping things all apart. It is pretty easy and makes the machine more reliable

Try a few turns on the idler screws, this should help grip and push the filament through the hot end. Make sure to clean the hobbed bolt from any filament after grinding occurs.

Thanks for the reply guys, i appreciate it.

The problem is, its not related to the bed. Because even whilst the printer is in the air, sometimes it grinds. I understand that if there isnt enough room between the bed and the nozzle it wont work either, but ive ruled this out. I wish that was the problem, id be able to fix it if it were ):

I have changed the idler tension from loose to veyr tight, both seem to have the same effect. i will grab footage of it tonight and show you guys. im so sad ):

Can you manually extrude if you undo the tensioner and just slowly manually push the filament into the extruder when it’s up to extrusion temp? Are you sure you’re not clogged? How were things inside when you changed the nozzle? When your print failed, there was still filament in the nozzle just sitting there for several hours at high temp and not being extruded. Some of it could have carbonized inside and caused a partial clog.

Hi PdxSteve, yes I can extrude manually but it becomes increasingly difficuly after a fwe seconds of manual pushing. I am positive i am not clogged; i just installed a new complete hotend and nozzle yesterday. I thought it was a clog so i bought a new hotend but this seems to not fix the problem

Hey guys. As promised, here are some videos of the printer. weird thing is, when i press change filament during a print (because it fails instantly) the filament gets retracted perfectly. it just decides to not print when its print time. i have NO idea why. ive changed temps to hotter thinking there might be a heating problem but nothing. Ive also attached an image of what the filament looks like when i remove it sometimes. it almost looks like its bunched up but once again, no idea why. please help me guys

It does look like your filament idler screws are too loose. Set them so you have around 5-8 mm between the washers.Make sure the hobbed bolt is clean.

Thanks for the reply. I have changed the idler settings heaps of times from low clamping to high clamping and it’s still doing the same thing. I can rule idler tension out. I’ve been printing with this printer for 2.5 years now and have only encountered this now

I have never encountered this myself… but I’ve heard of others who have had cracked idler arms or cracked gears (3D printable gears) that resulted in the hobb gear not having enough tension to drive the filament even when the tension was cranked up with the knob (because the crack would just push things away).

You might want to inspect the gears and idler arm to make sure everything is solid.

hi everyone. thanks for the replies and for your advice. trying to fix the printer became increasingly difficult and appears to be unknown. all elements are perfect but it still seems to grind. so i sold my taz 5 for $1000 AUD.i really loved my lulzbot and i was sad to see it go. it was snapped up 1 hour after listing.

id love to get another lulzbot in the future but for now i might buy a cr10s pro v2 to keep me happy.

thanks once again for all of your help.