10-31-3 for me
Got my printer on Friday March 20th, by Saturday night the hot end was oozing filament. I was using PLA then HIPS, both ooze out of the top of the hot end and into the block. My prints have failed halfway through because the filament gets clogged. I pushed the filament through by hand and that would seem to clear the clog but then my filament looks like a string of pearls coming out. I have sent a request to Customer support and I hope to hear back from them on Monday morning.
What do you do with a clog like this? How should you clear the nozzle and should you also take apart the heater block and clean that? I noticed some of you mention Acetone but I thought that doesn’t work on PLA or HIPS. Also how can you prevent eh filament from oozing out the top because of back pressure? Also the block and nozzle are fused unless I heat them up, I am assuming its filament that is all clogged up in there which is a bad thing.
I’m sure Customer Service will take care of you. However, I’ll elaborate on what I did to fix the issue.
Caution! Dragons Below!
You can damage your machine, and potentially void your warranty by following the steps below.
I had the exact issues you mention. I tried cold pulls but could never get any satisfactory result from them. I ended up heating to 230, removing the nozzle with an adjustable crescent on the heater block and a 7mm on the nozzle. Remove nozzle, careful it will be very hot, and go outside. I used a MAPP gas torch to heat the nozzle until the filament flowed out the big end. You will probably get some carbon buildup from the burning plastic so it’s important to clean it fully after it cools. You don’t want to cook the nozzle, just heat till filament slides out. Be careful of the threads, if you damage them you may have other issues. Once the nozzle is cooled, find a 7/64th’s drill bit and gently, by hand rotate it in the cavity to get any gunk stuck to the walls. Back inside, steal your wife’s nail polish remover, put some in a container and immerse your nozzle. Let it sit a while then shake it about, then let it sit, then shake a few times. Clean fully, polish with emery cloth / bluejeans and reinstall. It’s important to reinstall with the heater block hot, again careful here. Also be mindful not to cross thread.
It seems the real issue is the HIPS. Not sure if the Lulzbot HIPS has particulate in it but each time i use the black HIPS i have the issue. The blue Lulzbot HIPS I have is fine.
I took the same steps as discojohn… heated the hotend to about 165C (search hexagon nozzle removal on Google for detailed instructions) and removed with two wrenches 18mm for the heat block, and 8mm for the nozzle worked, 17mm and 7mm would have been better. The nozzle is hot so a pair of visegrips or large forceps work great to grip it… make a plan B to catch the nozzle if it slips off. To replace the nozzle, heat up the heater block to the same temp, and screw the nozzle back in… I re-tightened when the hotend end was at operating temp.
Note removing the nozzle isn’t recommended by Lulzbot.
Google for the appropriate solvent to dissolve your filament… Limonene seems to come up for HIPS, and MEK seems to have good effects on PLA.
I used acetone for ABS and was a little impatient. After a 20min soak (or until the solvent got cloudy) I removed and used a dental pick to scrape out the filament. Then another soak, did this a few times until last soak was clear. A piece of wire through the nozzle helped to ensure it was clear. YMMV
I did the same as the above two posters and removed my nozzle. Acetone does work on hips, but it’s very slow. I soaked my nozzle for a week and although the outside surface looked clean, I still had some kind of obstruction on the inside. What finally worked for me was holding the nozzle with the needle nose pliers that come with the taz and heating it up with a heatgun on the lowest setting. The lowest setting on my heatgun (cheap home depot model) is still 375 degrees celsius. So you have to be very careful as this is 75 degrees hotter than the hexagon heats up to on it’s on. After I had heated it up to the point where I could see light clearly through the nozzle, I put it back in the acetone to soak for about 20 mins. This fixed my problem and I have been printing every since.
That’s a good tip to use a heat gun. I’ve got a rework station that I can set temps on… need to try it next time.
I had this problem as well after upgrading my Taz4 to the Taz 5’s all metal hot end. I had tried the solutions listed here without luck, but did eventually stumble upon a solution that worked for me and I’ve been printing almost non-stop for the past 3 weeks without a problem.
The “wobble”, for lack of a better term, occurred right from the beginning on my first print, but since I also had (without realizing it) fried the smaller fan, all my prints would also jam / clog after 15 minutes so I started to think it was related. But after realizing the fan was dead, cleaning out the clogs, and replacing the fan - I could consistently print but the wobble was still there.
In fact, the prints were coming out perfectly without any failures (as compared to original Taz4 hot ends), except for the wobble. It seemed to happen more on the lower layers and I tried varying speeds, which made a difference, but not how I expected. Slow speeds seemed to have more wobble than faster speeds, but the was a lot of variation from material to material. And since I could get higher temps, I had been printing in MadeSolid PET+ and T-Glase (both of which need slow print speeds), but this meant I was really seeing the effect. Although it actually looked pretty cool in the T-Glase.
Anyway, I tried all the steps suggested here, but since I was nearly at the end of the 14 return period, I decided it must be a defect in the nozzle that I couldn’t repair and I was ready to send it back.
As I was waiting for Lulzbot support to get back to me I randomly came across: http://www.thingiverse.com/thing:755184 which talks about a harmonic ripples in the Taz 5 hot end and provides a strengthened extruder body.
I attached my old hot end, flashed firmware back to Taz4, and printed it out in ABS and installed it (without doing the other upgrades to the carriage the author mentions) and since then problem has been resolved.
If you go this route, which I would definitely recommend doing so since my Taz 4 is now more consistent than ever, make sure you have a long enough screw (60mm long) to mount the tool to the carriage. and perhaps have and extra idler printed first, seeing as its not easy to remove the idler. If you’re like me and it’s your first time fully disassembling and re-assembling the entire tool, then you may find, as I did, that out of frustration you accidentally destroy the extruder idler. The reason is, all the other components have either screws which can be easily removed or bolts whose nut can be accessed for easy removal. But the idler has a hidden nut that can’t be reached while loosening or tightening the bolt. The but is sunk into a correctly sized hole directly behind the head of the bolt / screw. The ABS should hold it in place, but can easily strip.
If, as has happened to me, the nut slips and strips the ABS around it, it becomes very tricky to remove. After destroying one out of frustration, and then seeing what the problem was I was able to drill a tiny hole for a M2 screw perpendicular to the idler mounting screw, behind the screws head just before the idler body meets the extruder body - so the drill bit hits the nut. Then screw in a small M2 machine screw. If done correctly, it will provide the tension on the nut so it can’t spin freely and the idler screw can be replaced.
In case you need to reprint the extruder idler: http://devel.lulzbot.com/TAZ/Juniper/production_parts/printed_parts/extruder_idler/
I hope this helps anyone still having issues!
Lulzbot, How do you know which extruder idler to print
Seems to only be one stl file in the directory…
kcchen, thanks for pointing the one stl file out. I missed that
Hey All, thought I’d add this to this thread in case anybody else runs into the same thing. I’ve been fighting for over a week with what seemed like hot end and extruder problems with symptoms like what have been described here. Extrusion was repeatedly stopping in the middle of prints, and the hobbed bolt was chewing through the filament. What I finally started to wonder about was whether the 5 pound roll of ABS I loaded a little over a week ago was just too heavy for the extruder to pull from. So I tried cutting a good length off the roll and printing from that. All the problems immediately went away, and I’m getting great prints again. So seems like that’s another thing to look at… anybody else run into this?
Definitely possible that the 5kg spool is too heavy for the extruder head to move… I’ve only printed with normal spools (2.2kg?). I did have a spool where the filamant was wound too tight and “sticking” to other filament. The extruder had problems during normal extrusion, but could clear when the head was performing non-print moves at higher speeds. To fix, I just unspool a bit of filament before a print or after printing.
Doesn’t seem like the filament is wound too tight on this large spool, but yeah, I’m now just unwinding some filament when I start a print, and around once every 30 minutes during longer prints. So far so good.
Wonder if having the spool on a ball-and-roller bearing instead of just a squared-off rod would help with this problem.
I’ve thought about the ball-bearing solution myself, but for now I only use 1 kg spools, and have wrapped the spool holder arm with teflon tape (used to seal pipe threads) for less friction, and haven’t had any extruder problems.
I did notice that spools with large center holes – like those from Lulzbot and others – sometimes climb up onto the shoulder on the spool-holder arm near the pivot end, then a little later fall back down with a very noticeable clunk. I expect while climbing up onto the shoulder the spool is generating more resistance to the filament being pulled off of it.
To minimize that I put a large washer onto the spool holder before putting on the filament spool. The washer’s center hole is just big enough to go onto the holder arm but not big enough to get up onto the arm’s shoulder, and it’s outer diameter is bigger than the spool’s center hole. Since doing that I don’t hear that “clunk” any more, so I figure it’s a good thing.