Howdy, I’ve been using my Revo Six for almost two months now. I did spend quite some rolls of PLA, PETG and ABS successfully, but recently I started noticing constant jams, only when printing PLA. I used the suggested settings from E3D website as a starting point, but I can’t seem to get rid of the jams which occur exclusively with PLA. my printer (a Farm from Brazilian manufacturer Sethi3D, pic below) has a Bowden setup, but I tried adjusting retractions (even turning retractions off) with no success. It starts printing and a few minutes into the print it starts underextruding than it stops, all symptoms feel like a heat creep issue, and it happens ONLY when printing pure PLA (I did try some old laying around "marble" PLA the other day and it didn’t clog). I’m using only the 0.6 and 0.8mm nozzles in my setup (only used the 0.4 for a single print and the 0.25 wasn’t even touched). ABS, PETG, Tritan, and other high temperature materials print just fine with no issues. And the weirdest part is that I actually managed to print some few kilograms of PLA (from various different brands available here in Brazil, about eight rolls) successfully before the issue started happening. Already tried to clean the nozzlebreak using various methods, from using cleaning filament (eSun) to the accupuncture needles. Issue still remains. ABS/PETG/Tritan prints just fine (I can actually remove the remains of molten PLA from the nozzlebreak with them) but standard PLA clogs a few minutes into the print, even with retraction off. Already tried also, so far: increasing hotend temp (up to 230C, I know it´s not the way to go but I did try it); reducing hotend temp (lowest I went was 190C for PLA); leaving enclosure open; replacing the heatsink fan (twice but still at 30mm, same specs as stock Revo fan - my printer had a generic V6 clone as stock so I already had a few 12V 30mm fans and V6 fan mounts as spare parts); changing brand of PLA (after the problem began, I only had success with "texturized" PLA - plain PLA , no matter which brand I use, fails) ; increasing print speed; replacing the whole PTFE tubing (twice, tried basic generic PTFE tubing and Capricorn XE, both failed printing PLA); reducing retraction length/speed or even disabling retractions completely; replacing the extruder stepper motor (only as a test, as it works fine with other materials); Replacing the extruder gear as it might be worn out (can´t put a dual gear one because the setup of my printer won´t have room for one), also only as a test, as other materials print just fine; cleaning the extruder gear with a brush and compressed air MULTIPLE TIMES to remove any remainder of old filament which might be making it "smooth" and skip, also no success; putting back the stock generic V6 hotend (it worked, but it´s not all metal, it has the PTFE tubing going all the way down to the nozzle - and it´s a pain to change nozzles, I got the Revo to get away from that thing LOL); Any suggestions? I’m considering moving to a 40mm fan but I´m not sure spending 20 USD on a Noctua will have any success. I did already print (successfully, with ABS) a new fan shroud anyway. Can I put a threaded PTFE coupler on the Revo Six? Does it have the threads for it on the top section?
So… I went to the Discord group and had some good ideas to check for. still, kept having problems. Went for the bigger fan (got a cheapo generic one instead of the expensive Noctua) and it seems to have solved the problem. I’m using a “vase mode drawer” from Thingiverse as a test print (as it takes about 30m on the 0.8 nozzle). I could never get past beyond layer “1.5” (started jamming at the half of the second layer) now it seems to be finishing even though I’m still on diagnostic mode (non-optimal settings, hotend temp lower than usual, etc). It didn’t clog and it’s almost finished.
