I'm obviously not understanding something about the E3D v6. For background, I'm a relative newbie to 3D printing. I built a kossel clear, with a knockoff J head (0.5mm), and it's been working well, but it leaks (which causes the tape to not stick and the thermistor moves around), and my ultimate goal is to print materials that I know the J-head can't handle. Having said all that, I'm getting decent quality prints in both PLA and ABS. Looking at the v6 reviews, and documentation, it seemed the v6 E3D would be a nice upgrade-- so the last thing I printed with the J-head was an ABS mount for my shiny new v6 (1.75mm bowden from FilaStruder in the US), which in a side note, is the first item I designed and printed myself. Assembly: Very nice (followed Tom's video). Fit/Finish: Superb. By raising the central part of the mount a bit, I only lost 5mm of height compared with the j-head. Got everything wired up (fan direct to 5A rail on power supply) and verified working. First, some calibration issues-- to be expected, but my first print came out reasonably well. Then the pain started. I wanted to switch filament... J-Head: Heat to 170, let sit for a few seconds, release extruder clamp, pull filament. Trim strings, leaving slightly melted pointy bit, insert new filament, push it by hand a bit to get the last of the old filament out. Tried this approach on the E3D, no luck. Heated to 190, still no luck. Heated to 210, nope. Tried 230 (and this thing heats up fast... another good point), and even after 5-10 minutes at 230, still couldn't remove filament. Finally, dismounted hotend, removed bowden tube, cut filament about 8 inches above heat sink. Removed nozzle. Unscrewed heater block. Used a small drill bit (about 1.6mm) and very carefully drilled out center of plastic until I could remove plug from heat break. Removed heatbreak, slid PTFE tubing all the way through heatsink, pushed the PTFE into the end of the heatbreak, and while occasionally loosing bowden coupler, screwed heatbreak back in. Put nozzle in heatblock, screwed back in, heated up to 260, tightened nozzle (I skipped this step originally by accident). I had now completed a filament change in about 45 minutes, by disassembling a key component of my printer. Next print: Cancelled due to underextrusion. Pulled filament out while it was still hot, before head cooled down. Next print: Now the fun began... I couldn't get it to extrude. Eventually, by cranking it up to 230, letting it sit, and manually forcing the filament in, I got a print going-- but again, under-extruding (Yes, I changed my nozzle size from 0.5 to 0.4). At the moment, I have a jam in the heatbreak that needs to be cleared, and will probably require the drill again. Looking at the drawings, the heatbreak channel seems to be 2mm in diameter. This lets the filament swell to more than 1.8mm, and I can't see how removal can ever work well, or am I supposed to remove the PTFE tubing every time I change filament? While "large retraction" works when the hot end is hot, it appears that if I don't retract before it cools down (power outage, unattended print, etc.), I now have a jam in the heatbreak that can't be removed simply by heating the hotend. What am I missing? What's the "right way" to use this hotend without getting the filament well and truly stuck? It is a very nice design that eliminates nearly all the complaints I had about the J-head... but it seems the j-head is much easier to use.
Well, that's embarrassing. Going through the survey, I realized I may have the wrong thermistor configured (I'm using Repetier instead of Marlin, so if someone could confirm I should be using "ATC Semitec 104GT-2", I'd appreciate it). Was set to 100k EPCOS (I'd replaced the one in my J-Head).
The fan that came with the hot end should be connected to 12 volts not 5. With 5 it probably doesn't produce enough cooling to prevent the heat creeping into the PTFE tube melting the plastic there causing jams. The thermistor should be number 5, the semitec. Finally, even when these things are sorted out you may still find that prints fail. This can be for a number of reasons. Jams in the nozzle, the V6 is much better than the V5, although that is a great hot end. The V6 attempts to address many of the shortcomings particularly in printing with PLA. But some of the fixes for the V5 can help with the V6. such as a tiny amount of vegetable oil on the filament from time to time. Also, rather than changing lots of things at once, change one thing and see what happens. Finally, one thing that has me stymied for a while was the extruder. The filament has been buckling causing it to slip out from the hobbed wheel. This caused filament starving and failed prints. This seems to be due to the back pressure at the nozzle when printing the first layer. That being said I have generated some really nice prints on a home built Rostock at 50 microns. Just one more thing to make life interesting.
That was 5A, not 5V-- amps, not volts. RAMPS board has two (incoming) 12 volt connections... a 5 amp and an 11 amp connector. Wired the fan into the 5 amp connector, so when the power supply is on, so is the fan. Since I'm running Repetier firmware, thermistor number 5 is "user defined thermistor table 0"-- #8 is the "ATC Semitec 104GT-2", hence my question. Fixing the thermistor setting helped, although now I have to find the right settings for the new nozzle-- some trial and error is expected. Changing filament is now significantly easier, and behaves as expected. Then I got carried away, and duplicated "too much retraction" jam-- while disassembling to clear it, one of the leads broke off the thermistor. Oops. :roll:
Hi, 5 volts, vs 5 amps, sorry my mistake, usually it is not a concern regarding how much current the fan can be supplied with, the volts control the speed, so I skipped over the amps part. Only once or twice have I got to the point where nothing I do, heating, cooling, cursing, will clear a blockage. At that point I have found that removing the bowden cable (Rostock owner), and cutting off the filament with a short length available above the hotend then heating the hotend to 250-270 degrees and a sturdy pair of pliers will allow the removal of the plug (this may well be different in the 3mm version). A small residue may remain in the nozzle. So from there, remove the nozzle, avoiding breaking the thermistor, yes, I have done this, then placing the blocked nozzle in a pair of helping hands threaded end down and heating it with either a small torch or hot air soldering gun will result in the remaining PLA either melting or burning away. At the present, most of my jams are extruder related. Skipping on the first layer, then not being able to feed filament from then on. I have a new geared stepper motor and extruder on the way to address this problem. Also I will try printing the first layer at 220 degrees, to help with the flow and reduce the back pressure in the nozzle. If things didn't go wrong, anyone could do it, that's what makes it fun!
Thank you, I feel honoured. I sometimes forget which setting is which in the Arduino firmware flavours, as I now use a Smoothieboard to drive my printer, and have toyed with using a Beaglebone Black.
One thing I've heard suggested for direct drive extruders has been to change the jumpers under the stepper driver to 1/8 microstepping, and cut the number of steps/mm in half for the extruder. I haven't had to go there myself, as I'm getting very little skipping when the hotend is extruding correctly. Speaking of which, I'm making better progress, but calibrating for the 0.4mm nozzle is not quite as easy as the 0.5mm I had before-- but I kind of expected that. Anyone have a suggestion for recommended nozzle distance to print bed that isn't expressed in units of paper?
