twistx

Steel sheath is stuck all the way in the block. This is how the interior looks.

Well, I did the atomic cleaning this time at 180C and I just took the whole print head apart. After it cooled to 90C I pulled out the bulk of filament still in the nozzle and there was nothing on it, no discoloration. I could see all the way down to the opening in the nozzle. I did this a few times to be sure. However just to be extra sure I decided to take it off and use the acetone to clear any obstructions that I can't see. I let it cool down, pulled the heating cartridge out, then tried the thermocouple but it wouldn't budge. So I stuck the heater back in, cranked the temp back up to 200C and tried pulling the thermocouple out again with a little pressure, this time the leads just broke off. Now the sensor is stuck inside heating block and I'm not sure how to remove it. There's much left to grab on to and pull and it seems to be jammed in there tighter than bark on a tree. The inside of the nozzle has a matte brown surface like its oxidized. So what can I do from here? My printer won't function and I can't clean the nozzle out because the sensor is stuck in it. Does UM cover this sort of thing or do I need to look for a replacement nozzle and sensor?

Thanks. I'll give that a try.

I did try doing the atomic cleaning method but with the bowden tube still connected. Multiple trys and the filament came out without any noticeable debris and was nicely cone shaped. Can't remember if I set the temp to 260 though, might have been lower. I'll try again tonight without the bowden.

Hello folks, I seem to be able to print OK parts at Cura's default 50mm/s speed but this test cylinder always fails. The 3 and 4mm/s levels are rather poor and it will not even get to 5mm/s. I haven't put anything through this machine but PLA so far. I didn't take any pictures because I have been just tossing the failed print's but I will take some for this thread as I continue to test. After reading through this thread here's what I've tried so far... I've disassembled the head and checked the ptfe fitting for friction and filament moves through that piece with no problem. It doesn't appear to be deformed so I replaced it and reassembled the print head. Next chance I get I'll measure with some calipers. Same with the bowden tube, filament slides right through. I tried adjusting the tension on the stock feeder assembly and increasing only leads to chewed up filament, while the lowest tension setting just creates skipping in the stepper. I printed out Robert's low friction spool holder and I still have the same results. Same with his feeder assembly. No matter what I have the tension set to this print fails in the same way as it did with the stock assembly. Other things I've tried were loosening the extuder motor bolts, and changing the current to 1.5A in the gcode. I've been using different filaments, the blue that came with the printer and some others that I've used with no problems on my ultimaker original. Also tried temp ranges from 210 to 240 and at the highest setting it just created a big stringy mess. The lowest setting gives me skipping or chewed up filament depending on the feeder tension. Even helping the material along by hand doesn't seem to help. I will be picking up acetone tomorrow to clean the nozzle out. I have some spare bowden tube that I will use to replace the one that came with my UM2. I'll take a good look at the print head while I have it disassembled. I'll also try running this test with a few of the other spools I have. I'm not sure what else to try after this though.

I've got the back end to 5-10/100ths within eachother. Leaving it there because I don't think I can improve it any further. Went on to printing the test cylinder because the first time I tried it didn't work, now I've installed Roberts extruder assembly and tried it again and still the same result. 3 and 4mm/s are poor, and at 5mm/s it either chews up the filament or the stepper just starts skipping depending on the spring tension. I'll move to the other discussion for those tests.

So I rebuilt the bed and ran a few test prints, just a hollow square 5mm wide and 1mm tall around the perimeter of the bed and the back side is still off by a few tenths of a mm. Doesn't really make sense to me since the glass is perfectly flat and the clips on the corners should pull the bed to the glass, so I took the back spring out and noticed it is curved. I turned it and put it back so it curves along the Y axis not the X and that seems to have reduced the difference to about .1mm along the back. Printing a few more times for calibration, but I might slightly adjust that spring again. I think that is the origin of my problems though.

Thank you for the responses. Daid, I appreciate you pointing out that flag. I'll rebuild marlin with that commented out. I have no doubt that these machines are tough, I put my original through all sorts of punishment, but I never underestimate my ability to break something. I discovered last night when calibrating the bed after the last collision that the home corner was .3mm lower than the rest of the bed. I took the bed off this morning and with a square I could see its definitely not flat. I didn't check this when I first received the machine but I imagine it wasn't like this before. There's no pressure on the square so the deflection looks a bit worse than it is when secured to the Z plate.

Yep, using normal gcode in Cura. Its not the actual printing process that this happens with. Its when I issue commands to the printer manually with Octoprint. From what you're saying I need to always home before moving any of the axis? I will test that tomorrow. But what is with the bed wanting to continue lowering when it is already in the home position if I issue another lower command? Does the software not see the switch state but only the transition? Even if the machine knows its position in software after homing, why would ultimaker choose to omit these switches that the original had to prevent this? There seems to be plenty of opportunity for collisions and at almost twice the cost of the original I expected to see more not less. Do you happen to know if the control board has the ability to take extra switches? I haven't examined the board yet. If possible I would at least install a top Z switch to prevent my bed from getting any more messed up.

Just to clarify, topic should say Printing over USB, but this issue happens when I input manual commands not when printing but I imagine that would be possible with some bad settings in your slicer. I'm using Cura again now, was using Slic3r but gave up on that. I'm also using Octoprint to monitor prints remotely from another room, which is also how I'm issuing manual commands.

Unlike my original ultimaker which had switches to prevent these collisions, my UM2 seems to happily run past the end limits and ignore switch states when an erroneous command is given over usb. This has resulted in the bed running into the print head on a couple of occasions. And when the bed is already homed it will still attempt to lower the bed further despite the switch already being activated. Same with the furthest location from home on the x and y axis, it will continue to try moving past its known limit if given that command. So what is needed to prevent this from happening, besides abandoning the printing over usb method that I've been enjoying? Buy and install more end-stops? Changes in the Arduino firmware? I've been extremely careful since I noticed this, but I'd rather be have assurance knowing the machine won't just destroy itself. It seems my bed is already slightly bent.

Hello everyone, I'm late to this party but I've been reading around trying to sort out some issues I've been having with my new UM2. All of my prints show signs of under extrusion on the infill, even when printing slow at 30mm/s or high temps at 230C. I tried printing this cylinder a few times and even at the 3mm/s level it seems the material is being fed too fast and the extruder motor starts skipping over and over until it chews a hole in the PLA and loses traction. If it does make it past the 3mm/s section, the skipping gets worse as the speed increases and eventually it fails all together. I have disassembled the print head, inspected the bowden tube, the teflon piece, and inside the nozzle after clearing out left behind PLA. Filament passes through the bowden and teflon piece without resistance. I removed the extruder from the machine and visually inspected everything and replaced it. I haven't been able to find a single direct cause to this problem. Any tips would be greatly appreciated, I have only had this printer a week but at this point I was already getting better prints with my UM1. I'm using the PLA from Ultimaker for these tests.

PM Sent.

Following up, I installed manycam and the added virtual camera helps with this issue. No more crashing.

Hey Daid, I'm having this problem as well. Deleting the vidcap.pyd doesn't provide a workaround. I also tried commenting out the webcam part in the __init__ section of the printer window gui. That didn't seem to work either. Specifically I have a Logitech Quickcam Pro for notebooks, with the logitech drivers up to date. When I open a program to record or stream the webcam, then open Cura and start printing usually the recording/streaming program ends up in a locked state while Cura keeps on printing. If I fire up Cura first and start printing then try to open the recording/streaming app both Cura and that program tend to lock up. The worst part of this is that ending the process does not work. The only way to terminate the locked programs is to force a reboot, where upon the shutdown process is interrupted by a blue screen and core dump pointing to USBSER.SYS. I tried the 13.12-test version too, but that wouldn't even start printing. Cura would just lock up when I press print. Anyway, I have had no other problems with this webcam or any of the recording/streaming apps used alone or in conjunction. Things only seem to lock up when Cura is running. Any tips would be appreciated. Thanks and Happy Holidays!