opit78

Filament is hitting the edge of the hole instead of going straight into the hole. Our UM2 is only one month old so we've opened a ticket with Ultimaker technical support, hope they gonna help us. That's manufacturer fault rather than user error or lack of experience. BTW check the white nylon coupler as well. Our is well wear off on the inside probably because extra friction created by faulty nozzle.

I just took our printer head apart and I noticed that nozzle hole is off centre, it's off a lot ! Literally is drilled at the angle. Look at the filament ! That's ridiculous. I'am pretty sure that my issue is here.

Last night's print with with filament diameter set to 2.55mm It went pretty well.

Thanks gr5. I've pretty much the same result as yours once I set filament diameter to 2.55mm instead of 2.85mm ?! What's going on ? It's possible that my extruder step/mm is that much off ? There is nothing wrong with Ultimaker filament, correct 2.85mm, nozzle is not blocked and in perfect condition, white nylon insulator as new, extrusion test goes perfect all the way up to 10mm3/s (with filament diameter set to 2.85mm).

Here you go, box 30x30x5 http://speedy.sh/D7bSu/test-box.gcode

I've updated UM2 firmware and Cura to 14.09, no difference. Also tried slicing with Cura on Windows instead of Mac, the same result.

This is not underextrusion, not I'm my case anyway. 6, 7 layers for top and bottom, even 100% fill doesn't work, you can always see layers from below between those gaps. Gr5 could you print simple box yourself and show us your result please.

Yes, same issue no matter what filament we use. Within last month we've tested almost 40 different colours, mostly Colorfabb and Ultimaker, PLA, PLA/PHA, XT, Woodfill Fine and Glowfill. Some of them flow better than others so problem is more or less visible but still exists. The best results so far we have had with glowfill and woodfill. I'm going to test Cura for Windows instead of Mac version just to see if there is any difference.

It has nothing to do with belt tension and we all have exactly the same issue which draws me crazy ! That's all about Cura IMO. I'm using 14.07 Mac version (if that make any difference Vs Windows version) Our second thread about exactly the same issue http://umforum.ultimaker.com/index.php?/topic/5375-top-layers-not-touching-um2/page-7

Hi Guys. That's definitely problem with Cura. Why the wall lines can touch each other no matter what direction they go but infill lines won't ?? Cura is creating too wide gaps between infill lines and even properly squished lines won't cover those gaps unless you over extrude a lot. I print mostly with 0.2mm layer hight I've this issue since I received my UM2 I can achieve all speeds without under extrusion issue, Ultimaker black PLA, 230C, filament diameter set to 2.85 With the same settings two infill lines are about 1.5mm wide (from edge to edge), each line is around 0.55-0.60mm wide, gap between lines is around 0.3-0.4mm (hard to measure to be honest) It looks like Cura is skipping every second line of infill, you can clearly tell by looking at flat closed surfaces. In my opinion is doing 0.4mm line, then 0.4mm empty space and then another 0.4mm line. For me only workaround to make those gaps less visible was to set nozzle size to 0.3mm (even if real size is 0.4) or to over extrude by setting filament diameter to 2.65mm instead of 2.85mm which I'am doing right now. Ultimaker black PLA Nozzle temp 230 Filament diameter set to 2.65mm Nozzle size set to 0.4mm (as it should be) Print speed 40mm/s 0.8mm shell

I've just received new PCB board (thanks to Ultimaker team). Happy days :-P

Initial layer thickness must be set at least 0.01mm thicker than half of the layer height value otherwise Cura gonna skip the first layer (initial layer) completely. If your layer high is for example 0.2mm then initial layer thickness must be at least 0.11mm Layer high 0.25mm - initial layer thickness >0.13mm Layer hight 0.1mm - initial layer thinckness >0.06mm and so on ....

Do you have any other filament to try out? If the filament is not consistent then probably you're not going to get proper pressure in the nozzle during print.

I've exactly the same experience with gold PLA from Ultimaker. Iam not able to print with it no matter what. Take some filament and try to break it with hands. Mine breaks very early on 5-10cm, after that is very flexible and not easy to break, 5-10cm further is hard and easy to break again?! I dont know, but this filament is really messed up. I've tried Ultimaker PLA pink, dark blue, bright green, orange, yellow and black, no problems with those so far (dark blue and black works best for us). Within next couple days we gonna test red, bright blue, white, transparent green, transparent blue, clear, flex black and flex white ones.

Hi. Have you got that fixed ? We've just run into the same problem. Last night both side fans stop spinning in the middle of the print. Wiring, plugs and fans are 100% fine (tested with external power supply and multimeter) so it must be issue with PCB board itself. Our UM2 is only 9 days old :( We've just opened a ticket with Ultimaker support but I wonder what they have done for you to sort it out.