Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble So I got my replacement heat break from e3D (thank you) and of course the first thing I did was poke at it with the microscope. Unfortunately the second one did not look much better than the first in regards to rough patches and ledges. They claimed to have inspected it, But these rough patches are easily visible by the naked eye, so I am a bit perplexed by that. Decide for yourself,. Heatbreak #1http://www.alexcphoto.com/Stuff/CleanBarrel.mp4 Heatbreak #2http://www.alexcphoto.com/Stuff/e3D_Round2.mp4 Then as a sort of sanity check I decided to disassemble a few other hot ends and inspect them with the microscope,. Brass J-head MK5: http://www.alexcphoto.com/Stuff/GoodJHead.mp4 Prusa: http://www.alexcphoto.com/Stuff/PrusaNozzleMKII.mp4 A random ebay heat break: http://www.alexcphoto.com/Stuff/China1.mp4 Ultimately only the prusa was mirror smooth on the inside surface (due to its construction it was hard to get light down its barrel, so the video is hard to tell, but you can just barely see that it is mirror smooth for the most part), (BTW, the prusa never jams with PLA). The others all showed varying types of rough surfaces(but still less than the e3D to my eye). But only the prusa is in the same price point as the e3D and only the persa is stainless like the e3D,. so it’s the only direct comparison I have here at the moment. So after venting a bit at e3D on friday in an e-mail for sending me another rough barrel (sorry e3D. it’s been a stressful week),. I decided to spend the weekend doing everything possible to get one of the barrels to work. I choose the second one they sent, mostly because the second while having about the equivalent amount of surface roughness it did have one or two fewer hard ledges. I tried the hot end stock,. Jam, jam, jam,. Right from the very first print, so no buildup over time as some have been suggesting. Then disassembled, & cleaned,. And I then repeated the seasoning process as I had with barrel #1. Same results as with barrel #1, things improved, 100% lockups stopped happening, but the amount of skipping and voids where still enough to ruin most prints, and from teh very first print again so again no build up over time. So I disassembled, & cleaned,. (I wanted to find a process that worked from as close to factory clean as I could realistically manage) Now I tried something new,. One user suggested to do additional polishing,. Stainless polish + cotton pipe cleaner in a power drill,. So I polished the barrel for a few min with the drill turning in one direction (half speed), while also moving the barrel slowly up and down the pipe cleaner. Then I reversed the drill to turn the other direction for a few min and polished some more in the same manner. And then a thorough cleaning first with wd-40 then with MEEK to dissolve and remove any residue from the polish. Finally a look down the barrel showed a bit of improvement. For the next step I did the seasoning as part of the 290c nozzle tightening process when I re-assembled (so I seasoned at a much more aggressive temp than previously suggested), in that I coated the inner barrel with canola oil (no plastic), ran it up to 280-290c & tightened the nozzle down (this did have the oil smoking, and spattering) then I dropped temps down to 210c and let the oil bake for 20min,. Then I cycled the heat up and down 5 min 210, cool down, then 5 min cold, then 5 min 210,. Cool down, Then 5 min cold,. Then 5 min 210,. (as instructed by a professional chef friend of mine) (Still no plastic in barrel) Then I ran filament through till all signs of the oil where gone. After that, now everything seems to be working at moderate speeds (Tested up into the 60mm/s so far), and a retract setting of 0.5mm (1/2 default in Repetier, this also seems to be an important variable.) I do not know which solved the problem, the extra baking in at higher temps & cycling the temp with oil present,. Or the polishing,. I suspect both factored in, But I will say this with 98% certainty, regardless of which one did the job, both point back to the roughness of the inner barrels as the culprit,. Unfortunately every time I suggest that e3D needs to polish a bit more, or that the roughness is part of the problem they suggest a different culprit,. I can’t say for sure who is right,. I don’t know their exact machining process, and as an unknown outsider they are dubious to trust my assessment over their own, and I don’t blame them, I don’t make hot ends for a living. But hopefully they poke at this problem on their own and come to the realization that a little more polishing can’t hurt, and trying it for a time to see the results might just pay out in fewer support tickets & complaints, only time will tell. I also suspect that the random placement of the rough patches have a lot to do with who has problems and who does not,. Aka some barrels can be that rough and be ok,. Others, if the rough patch is right near the glass transition zone,… jam (both barrels I received had the rough patches in the ½ of the barrel closest to the heat break in the glass transition zone, although #2 was a bit more spread out.) ---- Side note, since some have asked, Inc e3D, my extruder’s (All three of them identical) work perfectly with a j-head MK5, buddhashnoozle, Ubis, and a Prusa hotend @ speeds in the 80-100mm/s range (I have been swapping hotends out frequently over the last few weeks to test differences in print quality & maintanance so I can say this with certainty) I cannot logically consider my extruders as the issue if they can work with all of those well, but not with the stock e3D all metal, which should in theory be easier to push due to it having the smallest glass transition zone,. I have also experimented with three different hobbed pulleys for filament feeding and even one small diameter one that claims 33% more torque, and two different motor strengths (one that’s even powerful enough to direct pinch 3mm if I need it to), and I have a third even more powerful motor on order now to hopefully remove any chance of the problem returning. ---- Please note that all of my finding are for PLA only, simply because I’m stubborn and purchased this hot end for my PLA machine. ABS is a whole other ball park and from what I hear the e3D is absolutely great at that, so eventually I may just cave and put it on my ABS machine if the problem ever returns (if the seasoning ever wears off, etc.). The only thing I can say for 100% certainty,. Despite my personal experience with it,. When this hot end works, it produces absolutely beautiful results,.