ccw1984

A whole new UM2? How do I get in on that!? I've contacted support@fbrc8 about getting a new teflon spacer (on Feb 5) but have yet to hear back. I've been pouring over the forums, especially the thread on replacements/improvements for the coupler, the results with a vespel washer between the brass hot end and the PTFE look promising, I'd love to get my hands on one. Or something, anything that will last longer and let me print in ABS and PLA without having to worry about part failure. The glass impregnation should give the part more structural rigidity, so even if it has the same thermal properties, it should be less likely to develop the ring indentation that so many see when the part fails.

Aha, it was set to the default time of 5 sec, decreasing it to 0 changes the print time down to 1 hr 41 min (at 100 mm/s) so it is coming into play. Also it defaulted to "print one at a time", changing to print all at once decreased it to 1hr 39 min (100 mm/s). FYI, The plate of parts is from the UM2 Bearing Filament Guide (626 version).

I didn't see a comprehensive thread to bring together issues with Cura 15.01 so I figured I'd create this one for anyone to comment on along with my own. I'll probably be reading through the other threads and either linking or describing the issues here. If there is one already please point me to it. Printing Time Calculation: I noticed that the printing time seems to be calculating oddly now. I loaded up a plate of parts at 50 mm/s and it shows a printing time of 2 hrs 0 min, 1.21 m, 10 gram. If I change the speed to 100 mm/s however the printing time only drops to 1 hr 54 minutes, same m & gram. It seems like doubling the speed should have a bigger impact on overall print time. (I would expect nearly half) This is with the default settings immediately after installing 15.01. (20 mm/s bottom speed, 0.0 for all other speeds under Advanced)

So, quick recap just to sum up who has and what we know about using the Flex3Drive (or other flex shaft projects) on UMO and UM2: foehnsturm - Flex3Drive working on UMO, original design for Merlin hotend mounting here. Bas van Deursen - Flex3Drive working on UM2, older version with 200 step/rev feeder?, required custom shaft for hobbed wheel. restinpieces - Custom flex setup, not working correctly with 400 step/rev UM2 feeder. Erik van der Zalm - Created UM2 Flex3Drive carriage here also includes custom firmware for UM2 for 200 step/rev feeder, installed and working?, hasn't commented here yet? CCW1984 (me) - Purchased Flex3Drive, installing soon with Erik's design and apparently can "use the attached firmware and change the E steps with M92 xxx." for the 400 step/rev stepper motor, if that's what I have. So I actually have no idea which kind of feeder stepper motor I have on the UM2 I received (long story short I purchased in late Dec 2014 but believe I got an older stocked printer), if anyone knows an easy way to find out please do tell.

So I pulled apart the print head this weekend, and as I feared... That 30 hr ABS print did some damage to the PTFE coupler, the inner edge was pushed out and burnt, and inside there is a depression with red PLA still in it. What I imagine is happening is that at that point the PLA is warm enough to be soft and as the filament is passing through if any rough edge (from the knurled feeder) catches in that depression the force is enough to 'skip' the feeder. EldRick and I actually had the same idea (aside: I've purchased a Flex3Drive from him, so I'll be over on this thread soon), I ran a 1/8" drill bit through the end with the damage to remove the deformed PTFE, reassembled the print head annnd...it still under-extruded. Long story short I had to go up to a 5/32" to ream out the interior edge and "remove" the depression. I tried to make it a smooth transition from the original inner diameter (ID) to the new ID but I could only do so much with a drill bit and a round needle file. I've contacted fbrc8 about a replacement part. (Another aside: I purchased the UM2 in December from MakerShed which led me to believe I would be getting one with the newer glass-impregnated PTFE part, however I believe I must have gotten one that had been there for a while since it had an older feeder and (obviously) an older PTFE part.) So far it's doing MUCH better, but still clicking every now and then.

Perhaps we can look into food safe coatings, ie. epoxy resins or such. http://www.masterbond.com/properties/food-safe-adhesives-sealants-coatings-encapsulation-compounds http://www.masterbond.com/tds/ep30hv http://blog.adafruit.com/2013/05/16/3d-printing-and-food-safety-3dthursday/ http://www.nanocare-ag.com/kunststoffe_edelmetalle/ http://www.actega.com/terra/products/foodsafe-coatings.html

If you haven't already done so you should print IRobertI's improved feeder, or one similar. After installing it I haven't any any more issues with worn filament.

I think you may have a similar issue to what is happening to my prints. Check out the link, but basically after switching from ABS back to PLA or vice-versa, if all of the plastic isn't purged well enough it either doesn't get hot enough to melt and extrude (ABS) or it carbonizes on the walls (PLA) because of the temperature difference when printing the two. Overall however what this really is doing is introducing more friction (in the way of pressure) into the system, which includes friction from the bowden tube, the filament/spool, teflon spacer, etc. all working against the force the feeder stepper can provide. Reducing friction anywhere and/or everywhere else should help in preventing the dreaded 'feeder skip'. Also reducing the print speed and raising temperature a few degrees seems to help as well. I'm actually printing IRobertI's low-friction spool holder now. (reallly really slowly) http://umforum.ultimaker.com/index.php?/topic/9295-switching-between-pla-and-abs-thoughts-on-under-extrusion-clogging-burnt-pla/&do=findComment&comment=90051

Well, I obtained some http://www.amazon.com/Printer-CLEANING-filament-Makerbot-Printers/dp/B00O92RW92/ref=sr_1_2?ie=UTF8&qid=1422282125&sr=8-2&keywords=eSUN+3D+Printer+CLEANING over the weekend and ran some through the printer by hand. It doesn't really to do atomic pulls well, the filament is rather soft and so far has always broken at the sharp temperature change in the Teflon coupler when trying. However after running ~15-20mm of the filament through I am happy to say that so far it has been printing much better with only a few feeder motor 'hiccups'. I think from now on I will take the advice I saw on one of these threads to basically do a 'cold pull' when swapping material, instead of using the standard 'change material' procedure on the Ultimaker. So manually heat the head ('heatup nozzle') to ~90C for PLA or ~130C for ABS and then remove the filament manually to get as much out as possible. And may go as far as to always put ~10cm of the Esun cleaning filament before the next material to clean it out.

I tried multiple atomic pulls with the ABS filament I have (Gizmodorks transparent ABS) unfortunately: at 120 - 130C it either would NOT come out, or broke at the teflon connector without pulling anything out of the melt chamber. At 130-140 pulled out only a thin strand of ABS but nothing from the chamber walls like I was hoping. This ABS seems very brittle and will snap easily as I try to straighten it out for the atomic pulls. Also I noticed that as I push the ABS past the teflon insulator there is a slight bit of resistance at the base of it, where the teflon part terminates into the melt chamber, is there supposed to be any resistance there or should it be completely smooth? I've heard plenty about deformed teflon pieces causing problems, but I've only had the printer since late Dec and haven't printed that much yet, but again this was after a ~30hr ABS print. Next I guess I will be disassembling the print head and cleaning out the nozzle with acetone, fire, and perhaps brasso/metal polish as suggested to get it nice and clean inside. My issue seems to be more of a problem with volume reduction and the fact that the printer is still trying to force too much material through what is now a smaller volume opening, since it only underextrudes once the feeder stepper 'clicks' and skips back due to the pressure. Have you had luck with nozzle cleaning filament before? Is it the Esun filament, or just nylon? http://www.esun3d.net/cpxx.aspx?id=192&TypeId=26

So far I've been having a great time with my Ultimaker 2, but recently ran into an issue and I think I may have figured it out, but wanted to share my thoughts, hopefully a successful cleaning process, and to bring together some info and theories on material swapping, underextrusion, clogging, and burnt PLA together for discussion. Background: Printed nearly the entire spool of PLA that came with the Ultimaker 2, decided I wanted a lampshade and got some translucent ABS for that. Printed a nearly 30hr print in ABS (along with a few smaller pieces), which went fine. I decided to switch back to PLA (Red PLA from Push Plastic). I used the switch material option figuring that when it extruded again at ~240-250 the PLA would push any ABS out, but I started having underextrusion along with feeder clicking after lowering the temperature and switching the material back to PLA. I assumed that I had a few spots of uncleared ABS inside the head, so I did an atomic pull with ABS, another atomic pull with PLA and both came out fairly clean. Looking through the extrusion hole with a light I couldn't see anything blocking it, and it looked circular (ie nothing stuck on one edge). After fiddling with temperatures (figured maybe the red PLA needed a higher temperature) I was able to get an ok print by the end of it with a 95% flow rate, 225 C, and probably ~30-40 mm/s print speed. Theory: When switching from PLA to ABS normally, most of the PLA is pushed out, however some is left on the inside walls of the melt chamber and at the higher temps and long print time for the ABS part caused it to carbonize on the inside of the melt chamber, slightly reducing the available volume in the melt chamber and most likely the diameter of the nozzle. What I think is happening: Left: Printing Original PLA (blue), Middle: Printing ABS (grey) without clearing all PLA, Right: Burnt PLA (black) causing underextrusion due to lower melt volume & nozzle opening This is causing increased backpressure and the feeder clicking, which then causes underextrusion as it tries to "catch up" from not feeding for that second. Because the PLA layer is thin, carbonized, and stuck to the melt chamber pretty well, the atomic pull appears unable to remove it. Higher temperature makes the new PLA flow easier and lower flow rate effectively seems to simulate setting your nozzle size a bit lower. Possible Solutions (In order of difficulty): Atomic pull with ABS several times Clean bowden tube (reduce friction) Disassemble and burn out the print head Atomic pull with Nylon 618 (higher temp, possibly 'stickier' to the residue, would have to order some) Soak in chlorinated solvent/THF Links: http://umforum.ultimaker.com/index.php?/topic/3600-what-works-best-with-cleaning-an-ultimaker-hotend-nozzle/ http://umforum.ultimaker.com/index.php?/topic/8935-best-way-to-clean-old-nozzle/ http://umforum.ultimaker.com/index.php?/topic/9221-underextrusion-blockage-what-do-i-try-next/ http://umforum.ultimaker.com/index.php?/topic/8972-clean-burnt-um2-nozzle/ http://umforum.ultimaker.com/index.php?/topic/4118-blocked-nozzle/ http://bukobot.com/nozzle-cleaning

@twistx, @UltiArjan, @EldRick So does anyone have this up and running on their Ultimaker 2 yet? I would be interested in getting one if it's not too difficult to install and we have some success stories to back it up.

I was having kind of the same issue, where the very first part of the first line put down on the glass would curl up and not stick then cool in that position and get caught on the second pass. I fixed it by using hairspray instead of the glue stick (IMHO it's better because it provides a more even layer and I can ensure all points where it will lay down a first layer will be sticky) and by leveling the bed REALLY well. Now it sticks the first layer to the glass every time with no problems (so far, knock on laywood)

Those look great! And I'm glad it appears to have fixed your problems, hopefully it will work for mine as well. I was actually wondering what settings @gr5 is using though for his 30h long print with 109k retractions. I'm wondering if he has the stock feeder or perhaps IRobertI's upgrade. I think for something like that I would also put a small fan blowing on the feeder from behind to hopefully keep the shaft cool.

Can you post your retraction settings, and any modifications to your UM2? I've just gotten started with mine and I am having the same issues with grinding during prints with retractions (and even on some without any), and with the filament and/or knurled wheel slipping off. I plan on printing and installing IRobertI's feeder this afternoon and seeing how it work. Also I will try messing around with retraction settings.

I've gotten grinding 3 times in the last 3 days, only once on a print with a lot of retractions (Coral Cuffs on Thingiverse). I've touched the stepper feeder shaft before and it was pretty warm, possibly softening the PLA in there now, making it easier to grind. I'm going to give IRobertI's feeder a try and see how that works (if I can get it to print).

I would recommend tightening the set screw in the knurled feeder (spiky metal part) at the very least as previously recommended, I have been having the same issues with the knurled sleeve coming loose, filament grinding, and with the filament slipping behind the feeder knobs (up against the back panel of the machine). Other than that the printer has been exceptional! I am hoping to print out and install IRobert's improved feeder design this afternoon. See http://umforum.ultimaker.com/index.php?/topic/4393-ultimaker2-feeder-system-improvements-and-ideas/thread for details.

Just reading about the fan speed and just wanted to point out that this: "By default cura will slowly ramp up the speed of the cooling fans until they reach full blast at a height of 5mm. This isn't bad per say but we prefer to start the fan up a bit sooner. A setting of 1mm seems to work well." might not be the case for newer versions of Cura. Mine started with the "Fan full on at height (mm)" at 0.5.

Great guide! I'm reading through all of it now! One suggestion that pops to mind as I'm reading is to add something about supports to the 'Overhangs' section, and mention how Cura and other slicers (meshmixer, etc.) offer support options to help deal with overhanging parts. The level of detail on settings and such for overhangs could be left to other threads or your preference. Again, thanks for the guide!

Hello everyone! Been reading through various forums, learning about 3D printing, and just purchased and received my Ultimaker 2 the other day. So far things have been working pretty much exactly as I expected, which is good! I've got some questions already, so hopefully I can start and contribute to some productive conversations on here!