I was able to successfully print this mod and add it to my hexagon hotend.
It’s working great so far. I printed a 9hr print using PLA. This was my first ‘long’ PLA print in a LONG time!
Thanks for this!
-Adam
It’s working great so far. I printed a 9hr print using PLA. This was my first ‘long’ PLA print in a LONG time!
Thanks for this!
2 failed prints later, and it’s back to the drawing board. I just can’t get a PLA print to finish if it’s longer than 4 - 5 hrs. It will start to underextrude and then the nozzle jams. THIS IS SO FRUSTRATING
I’ve had many the same nights… Failed print after failed print. I’ve done a ton of reading, and nothing out there has helped. I finally stumbled across two things that ‘so far’ have fixed my problems. The first one, and I believe this was the major contributor, was that I’ve had rolls of plastic in my cabinet since I built it - 7 months ago. I was trying to swap out a roll for a different color, and when I tried to bend the end over (of the old roll) to hook it to the spool, the wire snapped like a twig. I mean REALLY brittle. I know this isn’t normal, so I tried it on several of my rolls, and I found that just about every roll I’ve had trouble with was like this.
Okay, so for me, lesson #1 was - old plastic = really brittle.
Since my feed system is different than stock, I’m certain I was introducing a lot of unnecessary tension on the plastic, leading to very easy “jams” that were actually just wire that was too hard to pull…
To test out that last statement, I took apart my fancy schmancy setup, and stuck a roll on top of my cabinet, hanging on a broom handle. I put clamps around it so it wouldn’t move too much, but could easily feed/roll. I then completely rebuilt my entire extruder assembly and leveled my bed within .0005"
The simplest things were just killing me the whole time (I think). I’ve got a TON of big prints coming up. I hope I’ve got it figured out! Either way, let’s keep this topic open, and try to solve this common issue!!
I printed 3 items that were all 7+ hour prints, with zero issues. (I probably just jinxed myself silly for saying that…) I’m attaching pictures of the indicator setup I used to level the bed, and of the prints. The last picture (of the turbo wheel) was done with no supports, 8mm brim. All items were printed with PLA @ 185°c, bed @ 60°c.
Plastic tends to absorb moisture from the air. if you aren’t storing it long term with a pack of dessecant, it may have absorbed enough moisture to cause brittleness. Mine never lasts that long so I’m not sure if that is what would happen. The other thing would be if your cabinet is getting residual heat from your printer (say it’s part of an enclosure system or something like that) the repeated heat and cooling cycles could be actually “un-tempering” the plastic for lack of a better term, and making it brittle.
Completely guilty. When I built my cabinet, I didn’t think I’d have my plastic last this long…
You are spot on. Cabinet pics HERE. My spools are stored on a feed roll under the printer itself in a cabinet made from 80/20 extruded aluminum and 1/4" glass. The cabinet was made specifically with the intent of retaining the heat for ABS prints. I was focused on making the printer work well, and didn’t even consider what I’d be doing to my plastic… Looks like the cabinet is going to get an overhaul this winter (at least the bottom portion!). I need to work out some kinks in the feed system anyway (see what I did there? 
). I keep getting failed prints due to the plastic being too difficult to pull. I need to work out a better way to route / feed the plastic, and this will fit right in.
Thank you for the info - it’s very much appreciated!!
Shiny looking Cabinet!
Looks like it shouldn’t be too difficult to put more of a thermal barrier between your printer and the plastic spools with that design. Good luck with upgrading it!
The white print shown above is a brand new roll of eSun PLA. It worked for the first print. The second of the same print had some issues, the third print failed completely.
Same issue, print starts ok, but after about an hour, it starts to under extrude and then will jam completely. Should I just accept that I can’t print with PLA on a TAZ printer?
If you are having difficulty printing PLA after a long period of time, one of three things is occurring. 1. You could be overextruding, and eventually plastic is creating enough overpressure on the nozzle that nothing can come out (probably not the issue if you can print ABS plastic with the same exact filliment diameter without issue). 2. You could have a failing thermistor or heater core and the nozzle is dropping below extrusion temperature during long prints (this is unlikely, would be affecting ABS prints, and can be checked via a cheap point and shoot infrared thermometer, or 3. The PLA is getting hot enough over time due to inadequate barrel cooling that it is expanding and jamming in the Hexagon hotend bore during long prints.
Number 3 is your most likely scenario if the PLA and ABS diameters are identical, and the issue only affects PLA. Your options at that point are as follows:
a. Check the angle and flow of the small “squirrel cage” cooling fan that is pointed directly at the hexagon barrel and ensure it is running continuously, is actually pointed at the barrel, and is flowing properly.
b. Swap that fan out with one or more larger cooling fans to increase the level of cooling to the barrel. You can run at least 2 small fans off the power feed to that particular fan safely.
c. Water cooling!
Try splicing in a couple of extra cooling fans and see if that does the trick for you.
If you take a look in http://devel.lulzbot.com/TAZ/Lancewood/production_parts/printed_parts/ it looks like Lulzbot is at least considering a larger fan for the hot end. That would be a good thing. I think a lot of folks have had problems with heat creep when printing PLA.
I’m not sure if you read most of this thread. It’s solely dedicated to adding an 80mm fan to the hotend assembly. If you scroll up, you can see that we’ve already done exactly as you suggested. That is, added a giant fan to the hotend. The problem is that we’re still having issues getting long prints with PLA to finish without jamming. Thanks for taking the time to reply but I don’t think this is the issue (for us anyway).
I can print with ABS and HIPS just fine but PLA gives me unending issues. I have also successfully printed objects with T-Glase with no problems. I just happen to have about 5 rolls of PLA that are currently useless. While I’ll admit that it was fun printing out the 80mm fan adapter and wiring it to the board, overall the amount of work for this issue has been very frustrating.
Ok, good luck fixing your issue.
so are we saying this doesnt work now? lol… is the electrical tape on the fins literally the best we have at the moment?
So the electrical tape on the fan/sink may be the ticket…
Im actually attempting to print an iron man helmet from PLA (full size).
Im on hour 36 and no jams. Using the tape on the heat sink as the only method for ventilation on the hotend.
Also, using my modified extruder to handle 1.75mm filament. The metal tube inside from hobbed to heater block.
Quite the test ill probably jinx it now.
46 hour total print time… 1.75mm filament , 75mm/s never an issue…
this took about 40% less filament than printing it upright. Not sure why anyone prints this in normal orientation .
the only extra thing i did was add the electrical tape to the fan and heat sink. seemed to work like a charm
The only support that was really needed was from the top of the heat to hold up the little jaw protrustion… but not that much.
Otherwise in the other orientation the entire inside of the helmet is support.
I took the 80mm fan and fan shroud off the hotend and added the piece of electrical tape between the squirrel cage blower and heat sink fins and have been printing with success. I’ve printed a few 4 - 9 hr prints with no problems. I guess this is the best solution.
whatever works right?
YES - exactly! Thank you for the persistence in testing, and especially for following up with all of us here. I for one absolutely appreciate it!
Thanks
My humble opinion is that the 80 MM fan is way overkill. Look into what i did with the new mangrove / lancewood files for the solution.
http://www.thingiverse.com/thing:1149597
https://forum.lulzbot.com/t/dual-cooling-fan-upgrade-from-mangrove/2489/1
I might be known to overkill just about everything.
Nice!! I’m trying to solve some minor heat creep issues on my stock hex V2 toolhead. Will that extruder fan duct fit onto the old toolhead?
No. I’m sure you could modify your extruder mount to use it, or you could print the mangrove mount and just not add the left fan.