rhymeandreason

My ultimaker 1 with the HBK just started having this same problem today. The bed starts heating up even if you haven't started a print. :( And it just keeps heating up, even with bed temperature set to 0. Does anyone have a fix for this yet??

Wow this is a super informative thread. btw, @MendellS, how did you make so many ptfe isolator parts? Did you make a mold or something? It would be handy to be able to buy extra ones since they do start wearing down after a lot of printing.

Wow, impressed by the perseverance to get Ninjaflex working. About a month ago I bought a Lulzbot with a https://www.lulzbot.com/products/flexystruder-tool-head (because business reasons) It prints Ninjaflex perfectly. Retraction and everything. I've mostly been printing flat things, so you can't really compare to the octopus. (Weirdly, I can't print pla on the lulzbot because it doesn't have a fan...) Anyway, settings used: 230 degrees C .2mm layer height 30mm/sec @Robert Amazing that your feeder design works so well. I mean, it's kind of overcoming a lot to push that elastic filament through the bowden. The Flexystruder from what I can tell is a modified Wade's extruder. Lulzbot has http://ohai-kit.alephobjects.com/project/flexystruder_assembly/ on making your own on their site. It looks like the main mod is a ptfe tube that holds the filament so the extruder bolt can gently push it along.

It's kind of funny how simple it is. My ultimakers work fine, but it would be nice to have a way to switch to direct drive for some filaments. Although, perhaps you don't actually need a motor that big? (if the goal is not to just use the existing parts.)

@3Poro Wow, that is really interesting! So I recently got a 2nd Ultimaker 2. And I noticed that it is a bit different from my first Ultimaker 2. (I had gotten one of the pre-production Ultimaker 2's.) The new Ultimaker 2 seems to have a much tighter feeder. I have it loosened as far as it will go, but it is really tight, and sometimes it chews into PLA much more than it should. I wonder if that is why people are having trouble with the extrusion. Indeed, this would only make the problem worse when using flexible filaments. Great to know that replacing the feeder can vastly help. I am not having problems with the outer walls of Flex PLA not sticking to each other. Try increasing your temperature? I had some layer adhesion issues with the MatterHackers Flex PLA, but Form Futura adheres pretty well.

Heads up everyone-- The PolyFlex material only has 4 more days on kickstarter. It looks like it has much better adhesion and retraction properties. @netsrac Admittedly bed adhesion is tricky. With hairspray, you have to use a lot of hairspray. Sometimes a glue stick also works, but you really have to get it even. And depending on what you are printing, I've found that blue tape, cleaned with rubbing alcohol, and no bed heat works. And it did take me a while...the whole first month or so I couldn't get any flex filament to print.

I have also just ordered Lulzbot printer, which is supposed to be better for flexible filaments. They even made a "flexstruder" specifically for the Ninjaflex filament. I've also thought that it would be nice to have a direct feed extruder that you can mount on an Ultimaker.

@3Poro You might just need to put more oil on the filament. I find that if you're printing something big that takes over an hour, the initial oil isn't enough and you have to put some more on later. You can tell if that is the problem because the filament will start getting wavy looking in the bowden tube. If your nozzle is clogged, it will make that clicking sound when it's printing. Then you'll need to clean out your nozzle. @alnavasa and @yellowshark Recreus filament would have an even worse problem than Ninjaflex. It is even softer than Ninjaflex. I tried Ninjaflex several more times. Sometimes I can get it printing for a little bit, but it will jam after about 15 minutes. The problem is simply mechanics. The soft filament is elastic. It's like trying to push a rubber band. Unfortunately Flex Filaments work better with direct feed machines rather than bowden type machines. There are several new flexible filaments that are coming out, hurray! I might write up all this information later in a better format. It's so silly that you have to hunt all over for material info.

Thanks everyone for your tips! After trying lots of times, I think it really is that the design is too wobbly and not stable at all. The whole thing only has the bottom aluminum plate to grip on to, and the 2 wood plates in the middle that actually hold everything in are completely loose. I tried putting in 2 nuts on each one, between the wood plates. That worked, and I got it leveled, but as soon as I put filament through, it pushed the whole thing out! Now I'm printing some extra parts to clamp the bottom pieces all together. Looking at the UM2, the bottom part is where all the important stuff fits together, and it needs to be a fixed height. Thank goodness this is my second printer. Not sure how you would manage to do it without another printer to make extra parts. If it works, I'll post what I come up with. *cross fingers!

I'm assembling the dual extrusion kit, and got almost to the finishing point with the instructions in the Ultimaker wiki, but then got stuck. In the instructions, it says that the new nozzle (placed behind the new nozzle), should be just a little higher than the old nozzle. No matter how I try, I can't get that to happen. It seems impossible, since I can't even get all 4 of the long screws to go in evenly. Is there something I'm missing to this? I looked around for mods people have done, and only found this: http://www.thingiverse.com/thing:169888 It looks like a different printhead mount for the 2 nozzles, but don't know where the thermocouples would go in that design. And I don't know if that would help with the leveling issue. Plus, why is the new nozzle supposed to be a little higher? I thought you would want to make them both exactly leveled. Any help is much appreciated!

Sometimes I make my own support material in the model. I notice that making long thin walls that print as straight lines makes the support easy to remove in pla. No dual extrusion in the UM2 yet, but once that happens it would solve many support issues just by using a dissolvable material.

@Daid Okay easy, I test with the "Cute Octo" model from Thingiverse. http://www.thingiverse.com/thing:27053 Maybe it only happens with round things? I also took a photo...It's kind of hard to see because it's clear filament. Left one is from older gcode, Right one is from new Cura gcode. The surface on the Right one is bumpy where it's smooth on the other one. https://www.dropbox.com/s/82ojrbmg6f7gbil/IMG_4939.JPG speed 50mm/sec .2mm layers 20% infill .8mm shell

@Daid Does it help if I send you the gcode? I tried both USB on an Ultimaker 1 and SD card on Ultimaker 2.

Okay, just tested with a model that I had saved gcode from before. Sliced in new Cura, and the outer shell is printing really slowly, even though I set all the speeds to be the same. This results in uneven blobs on the print, since it seems the flow rate is constant. Well, this explains all my printing troubles from yesterday.

I'm also having some issues. It seems that no matter what I put in "Outer Shell speed", it is making the shells slower. Hard to say for certain. I might just downgrade to the last Cura release until things get more stable.