gr5

Well, hopefully you thought of this, but if you rotate it 90 degrees you won't have any overhangs anywhere. Cura lets you do the rotation - just click, then click on rotate icon in upper left area then drag it by 90 degrees. But if you are just pointing out a bug then I've seen this bug also. I know - it sucks. I don't think this part actually needs support in this position but I would never print it in this position anyway as it would fall over so easily. One would need lots of brim.

The thermister part scares me the most. You dont' want to continue using the existing thermocouple and AD595? I thought these thermistors don't do so well at temperatures above 200C but I'm not certain. Anyway you'll have to build your own custom firmware if you switch to a thermister and insert a 4.7K pullup in the circuit board (there are holes for that ready to go). Here's a great custom firmware builder: https://bultimaker.bulles.eu/ But notice that even the thingiverse link you point out still uses the original thermocouple that comes with the UMO. I really recommend sticking with that method. Also note that thermocouples are all identical no matter who the manufacturer. Same with PT100 temp sensors (not supported by older UMO electronics) but thermistors are crazy different from manufacturer to manufacturer. A "100K thermister" from one company might have a different curve than the next company although I suppose all 104GT-2 might be the same. Not sure. Finally and probably most important of all - all metal hot ends kind of suck with PLA. They are great for other materials like ABS but for PLA - the semi-molten PLA sticks to the metal and everything is fine until you go to do a second print and you can't get the PLA to move up or down. Or in the middle of a print with lots of retractions the PLA gets stuck and the print is ruined. It's not a problem where the metal is colder than 40C. Not a problem where the metal is > 150C. It's the in between area where the UMO has teflon. But if you are certain you will NEVER print PLA ever again the e3d hot end is fantastic.

Set the bed to 110C. This is probably your only issue. You can start printing when you get the bed to 100C. Enclosing the printer will help with this. There's a big difference between 90C (below ABS softening point) and 100C (above ABS softening point). Consider lowering the fans even more. This part seems to have no overhangs. If there are no overhangs and no bridging then you don't need any fan for ABS - just turn it off. Your first layer looks squished enough but it's hard to say - more squish is always better even such that it becomes transparent. Here's a relevant frame from the above video:

What stu said. Slide up the mesh and/or take apart the head until you find all the fan connectors. There are 2 connectors for the side fans connected by a loop wire. There may be an unused connector (for the 2nd extruder which never happened) and there should be a connector for the rear fan. Jiggle that. Push and pull on it. Play with it. If the fans turn on and off repeatedly while touching it then one of the wires is probably very loose. Tug gently on each wire and if one comes off - then that was the problem. Consider soldering it all together. Sometimes you can just physically push it all together better and move the assembly to an area where the head can move to the 4 corners and the rear fan keeps working. Sometimes you have to take it all apart. One solution is to just cut out the connectors completely for the 3rd fan and solder the wires together (and cover with heat shrink!). If you do cut the wires or dissasemble cut the power first so you don't destroy your PCB by shorting the wires together.

The UM2 can put out 40W power - all you need to do is put in a 40W (or 35W) heater.

>Oh and if I do an edge layer it will not be strong enough and break too easily... It shouldn't. There should be no "grain effect" with PLA. If you are printing ABS and you are getting bad layer bonding this is very common but pretty easily fixed. Mostly by reducing the fan to zero or close to zero. With UM3 I would try 1% fan. With UM2 I would try 20% fan for ABS.

Hmm. Okay - doing it in Cura 2.3 is pretty involved apparently. I think you have to create a new profile and edit the javascript files. I don't know how to do that. Yet. In Cura 15.04.4 it's pretty easy as shown here. I still use Cura 15.04.4 for my UM2+ (and cura 2.3 for my UM3). Older versions of cura here: https://ultimaker.com/en/products/cura-software/list

First know that this is not officially supported for a reasonably good reason. You can get it to work but it's just not as reliable. Not just because your computer might go into screen saver mode or upgrade software or simply be busy for a few seconds and this can ruin a print. But also because USB is just not very reliable with UM2. So you might have to try a few different USB cables and a few different computers and you might need a USB buffer for stronger signals before it's reliable. It might work fine and fail 29 hours into a 30 hour print. Certainly if you plan to do this a lot you want to check the log files and the checksum errors. If you get more than 1 checksum error every 10 minutes then you are skirting danger. Anyway - that doesn't answer your question. The main thing is you have to change the machine settings to be in "reprap" mode. And not "ultigcode" mode. Ultigcode does not work through usb. So once you change this the first thing you should notice is that now the bed and nozzle temperatures are set in Cura and *not* on the machine. The machine will ignore your material temperature when you print through usb. Let us know if you have trouble finding the machine settings in cura.

1) get a 40W heater - this should be the only thing you need to do. Maybe you'll have to lower the PID but possibly not. The symptom if you need to lower PID is the temp will fluctuate quite a bit. 2) Make sure fan shroud isn't touching the bottom of the olsson block. with things cold slide paper from the back of the head under the nozzle to make sure it's not touching 3) If 40W isn't enough consider getting the block V3 and the race nozzles from 3dsolex. Those can transfer about 2X heat to the filament and you can print at more reasonable temps. 4) Don't print at 245C! Print at like 220C. Printing at 245C is a problem - it's bad for you teflon part. If it can't handle printing at 245C it still might be fine at 220C.

I'm pretty sure it's the 3rd fan. You may have never even noticed the 3rd fan but I think it stopped working - probably a problem in the cable. As soon as the head gets above 40C the 3rd fan in the rear of the head should come on. I think it's not. If it's broken then slide up the protecting cover and there's probably a loose wire or connector that came disconnected up above the head.

@canadadrones - well I've made cookie cutters and even 1mm thick cookie cutters are quite sharp enough in my opinion. If you really need them sharper then you need to print them on edge I suppose. If you print them vertically then you can get them as sharp as you want. But now you might have support issues. Or you could use a smaller nozzle such as a 0.25mm nozzle (and tell cura it's actually 0.2mm) and now you can get super sharp. But really I found 1mm plenty sharp.

Filament that is 3.1mm won't hurt your printer - the problem is it may get clogged in the bowden. If it's PLA you can get it out by removing the bowden at both ends and then heating it in hot water and sliding it out. The printer itself will not be damaged. I'm quite confident there will be a 1.75mm conversion kit for the UM3 within a few months so that's another option. Anyway 2.9mm filament should be fine. That leaves you a bit of room to have the feeder warp the filament into a bit of an oval and still fit through the bowden.

Fascinating. Well @ultiarjan the same symptom is true of the newer formulations of Ultimaker PLA. If you leave it in the bowden for 8 hours it becomes very brittle! And it has nothing to do with moisture but has to do with mechanically straightening the filament and holding it in that position for many hours. I really don't know why it does this. I'm guessing you get micro-fractures occurring slowly over many hours. Or maybe something down at the chemical bond level? What REALLY surprises me is that this same thing happens with non-PLA. I did *not* expect this to happen with PVA. I have not experience brittle PVA yet. I was always nervous about humidity so after every print I have always put it back in a bag with dessicant. I have a stress/strain machine that I built myself and gives me stress/strain curves just like the ones shown above. Some day I plan to print up several PVA test parts and then expose them to different levels of humidity/water for different amounts of time and then test them on the machine to see what the curve looks like.

Your posting is confusing. I think what you mean is: Running two curas on 2 different computers WILL sync but only if they point to the same folder and only if you only run one Cura at a time.

I think it's best if only one cura is running at a time if they are both accessing the "same" profile folder. When I same I guess I mean "synchronized through dropbox".

I didn't know that PVA gets more hard or less flexible or more brittle when wet. That's very interesting! I think this is a good test for my stress/strain tester machine!

I've never been 100% happy with cura support structures. It's such a waste that you bought the um3 yet you are doing single filament - too bad you didn't get the UM2. Well I don't have any great answers. I'm reasonably happy with the cura 2.X pva support options but those don't apply here. I would probably just put my own support in cad. You don't need any support for the square parts that have bridging. But for those L shaped holes you have to support the base of the L. Just not the top of the L. For cylindrical parts you really need support on both arcing walls. I'd make a very very thin wall that touches at the top in 5 or 6 spots. A thin wall on the inner and outer edge of those bridging arcs. Just to reiterate. The printer bridges pretty well. So if you print like a doorframe - you dont' need support at the top of the door. If you print with PVA it will make the pva stick out of the part - by default 3mm "horizontal expansion" which is perfect for these prints. The pva can have a smooth top surface for the PLA to lay down on top of and it will come out very nice. Here is a great example of what I mean by arcing support walls - the red portions on the lower left. This is a solidworks rendering. In real life it's all printed as one STL file in one color and you easily break off those thin "red" walls.

I was also thinking your support pattern was a bit open and sparce. But I didn't say anything because I can't see how that has anything to do with it sticking to the raft.

I think we got way off topic. The original poster *might* have a problem with humidity but most likely, not. There are other causes for ground up filament. Similar to those of normal filament that gets ground up. If you print the material too fast and too cold then it slips or if you have so many retractions that the same piece of filament is retracted 10 times (the same exact spot of filament goes back and forth 10X before getting through). Or 100 times. Or maybe your tension is too loose. Or too tight. Although I have to say tension looks about perfect. Hmm. Most likely you have a partial clog and the printer is having trouble getting PVA through the nozzle. Maybe it's time to do the cold/warm pull as recommended for PVA clogs by ultimaker.

Yes! Ultimaker is very open. This is the MAIN THING that distinguishes Ultimaker from closed source companies. This is the main reason why Ultimaker is so popular. You can mod your printer and not violate the warranty unless your modification caused it to break. Ultimaker was founded by 3 hackers and they think it's great that people hack their printers.

Actually looking at the photo one more time - it does look like massive overextrusion. On overhangs there is enough space for the high pressure filament to leak out all over the place but on most layers there just isn't enough space so the filament slips or grinds instead. overextrusion can be caused by Z errors or E errors. If the Z axis isn't moving as far as expected you would also notice your parts are the wrong height. By like half. Are your parts half the height they were supposed to be? Make sure. E errors - wrong steps/mm or accidentally set flow to 1000% or something. I would retract the filament until it's part way inside the bowden and then extrude exactly 10mm of filament (or say 25mm or 100mm) and then measure to see if it moved the right distance or instead what I expect to happen that it moves twice as far as expected. If you have tinkerMarlin installed you can see this easily in the move menu. Maybe you put the wrong firmware on the printer? The um2+ uses twice as many steps/mm versus the regular um2.

Even though it looks all "melty" - that's not an indication you were printing too hot.

The printer can't print in mid-air - gravity will pull the filament down. That's the basic problem. The blue arrow points to an overhang that's about at 45 degrees. If you imagine the layer that sticks out the most being laid down - you can imagine that it's mostly over air but just barely attached to the layer below. The red arrow points to a layer that was out over air. I imagine there was an overhang here. One solution is to reduce your layer height. You have very thick layer heights (which makes for very fast printing!) but you get these "printing in air" issues. With a layer height half the nozzle width you can easily print 45 degree overhangs with perfect quality. It will print even with almost horizontal - up to around 70 degree's from vertical or 20 degrees from horizontal. But with your roughly 1 to 1 nozzle width to layer height you can just barely print 45 degree overhangs.

Strange! I never touched the default PVA printing temp of 215C on my UM3. I haven't had this problem. Try it without raft. I don't use raft. Has your PVA absorbed so much water that you can hear the water sizzling and boiling as it prints PVA? If so then that's probably the problem. But the raft looks pretty good so maybe it's just printing the PVA too fast? Did you mess with the printing speeds for PVA? Note that I believe the printing speeds for each material are different - you have to select in cura which nozzle (left/right) before checking/changing settings in cura. I know - it's confusing.

Why do people want SVG output? Is this for visualization? There are already 3 or 4 fantastic, free gcode visualization tools. Is anyone interested in more details about that? Or is there some printer out there that only takes SVG?