gr5

Push hard inward on the orange part - that slot fits a screwdriver nicely and then push on the screwdriver while inserting or removing wires.

On the UM2 the 6mm rods snap in and out of the blocks in seconds. You can flip the head upside down or mount it "ass backwards" in about 15 seconds. The rod parallel with the X axis is long and sticks out past the blocks. The Y axis does not and doesn't stick out past the blocks. This is because the X axis rod is what hits the limit switch when homing. I don't think it has anything to do with dampening vibrations. But it's good that you think about things like this.

I would try the lower current first because that helps both with over temperature issues (really rare unless it is very hot where your printer is - like 35C or 90F) and it also fixes some issues some people saw recently with some defective boards or parts or something.

Did you at least make it easy to know where to place all those window frames by having the main body stick out or something? Or did you have to very very carefully place each window?

Woah - what? How did you do those dark window borders - are those printed in this orientation? Vertical? do you have dual color printer? Or are they printed flat? Or are they added later? Very nice.

So there are 2 things that come to mind when you mention the Z is also moving. One is that there may be a new issue that UM is dealing with were some of the new boards have too much current and sometimes the Z axis drops suddenly for apparently no reason. It seemed to be related to too much current which seems strange but maybe it's an overheating thing either on the board or in the stepper motor (probably in the board). One fix that worked for some people was lowering the current to 1200 ma. I'm not sure if that's the Z axis only or all the axis. You can do this on a single print with gcodes: M907 Z1200 (1300 is default) or M907 X1200 Y1200 Z1200 (to do all 3 axes) or you could just try removing the bottom cover and print with the printer on it's side (it prints fine upside down also) and with a fan blowing on the circuit board - just to see what happens (is the air around your um2 warmer now than it was in the winter?) It might not be a heat issue and might just be something weird on the new boards - I know for sure if you use too much current the steppers do very strange erratic movements and make strange sounds. The second thing that comes to mind is that there is still a bug in marlin where it sometimes moves some of the axes much faster than they can possibly move but only when moving at least 3 axes at once (and if the extruder is freaking out then all 4 axes). Normally this doesn't happen and the Z moves alone but if there is a gcode that moves Z at the same time as x or y that could possibly explain one of your issues. The bug is very consistent such that if you do the same set of gcodes 3 times it will consistently move the Z axis (and maybe E also) well above it's max speed. This seems less likely the problem. There may be a 3rd issue. It would really help to see a video of the extruder when this happens. With audio.

Okay, that was me. I didn't see this thread until Joris just pointed it out - sometimes I miss a thread. I'm following this one now. I thought you were talking about normal extruder-suddenly-slipping motion - is that what you mean? Is it somewhere about a 1/4 turn on the extruder?

You can print faster if you do thinner layers. Try it in Cura. Hover over the yellow and it will tell you the volume per second of filament you are trying to print. In practice though if you want thinner layers then you probably want higher quality. And if you want higher quality then you want to keep it under 40mm/sec anyway. Another option is to go with a larger nozzle - say a 1mm nozzle and print at 300mm/sec with that. Also because the head is very light on the UM2, the acceleration is very high - I think 5000mm/sec/sec is default. Whereas most printers have the extruder on the head and the max accel is closer to 500mm/sec which is 10X slower for prints that are small or don't have long straight movements because they never get up to full speed. Anyway - go look in this area to see the quality of the UM2. For speed just get a larger nozzle: https://ultimaker.com/en/community/view/1467-post-your-latest-print?page=338 Start at the above link and scroll backwards looking for photos - every once in a while you will see a print that will amaze you.

The i2k isolator will keep your teflon part at 100C even if without it the bottom of the isolator would have been 250C (nozzle temp). Unless you do retractions - if you do retractions all bets are off because each retraction brings more heat and further distance up the print head. The 3dsolex isolator should not last any longer but it is a bit slipperier. It is official dupont teflon and not a different name brand. The Ultimaker isolators are glass filled - they are ever so slightly darker in color due to the glass. The glass is supposed to give it some strength but I'm skeptical that they last much longer than the pure PTFE ones. 500 hours seems about right if you are printing at 260C. No one seems to have good data on how long they are expected to last if used at a particular temperature. They last much longer at 210C than at 250C but no matter what temperature you print at they seem to go soft eventually. You can also drill them out and they will last a little longer. It also seems to depend maybe on the pressure - how hard it is being squeezed by the spring above it and also how hard the bowden is pushing down on it.

Also try printing something tall and skinny - maybe a cylinder. Then when it is done print another one and see if the horizontal lines tend to line up - repeat in the same patter from print to print. If so then it's definitely related to Z screw or Z hardware.

You need to specify country but in USA I recommend printedSolid.com. Great guy who runs it (Matt) and he has lots of great filaments (not cheap - but don't waste your money on cheap filament as it's worth it! Definitely worth it to get good quality filament). Another great source is dynamism.com which sells ultimaker brand filament (my second choice).

I just scale the part. stl files don't store unit so it's up to the saving program e.g. blender to pick the units. Typically CAD programs save in inches or cm so if your cad program is outputting in inches then just scale up by 25.4. Alternatively somewhere in blender and sketchup settings there might be a way to indicate the units you want in the stl file. Select mm. Or if your part is in cm you might need to scale up by 10X. It should be one of these 2 numbers (10 or 25.4) so if one of these numbers is pretty close, it's probably instead perfect.

oops. bad post. Was confused. Total rewrite: This could be several things - most likely your Z stage isn't moving 0.2mm each time - some times too far, sometimes not far enough - when not far enough you get too much filament and you get a stripe that sticks out - when you move too far it sticks "into" the model. Check the Z movement carefully, make sure there is no binding or nothing is rubbing - it could be far from Z screw - it could be something rubbing anywhere on the stage. Try adding some grease to the screw and oil to other parts. Or it could be filament diameter - cheap filament will vary quite a bit even over just 1 meter and you will get this kind of pattern. Check the filament with calipers. This is one advantage of 3mm filament I think maybe. Or it could be temperature. Look at the temperature readings while it prints a "bad" layer. See if it moves more than 3C - it shouldn't - it should be steady.

Noted! If someone else ever asks I will point them to this thread plus I noted it for myself if/when I ever try it.

Okay - many points... 1) Even if you are printing HIPS continuously I am told it is very very easy to get a clog. Unless you print fast. Even just the act of heating up the nozzle to 235C can possibly get it to clog but more likely to happen on a long print especially with thin layers such as .1mm where you are extruding more slowly. But again, I am just repeating what I've heard - no experience. 2) You can create a hips material a few ways. The simplest is to go to MATERIAL CUSTOMIZE, then change bed/nozzle temp then save it and choose new or custom. It will create a CUSTOM1. The better way is to save settings to SD card, put SD card in computer and rename CUSTOM1 to HIPS or just create a fresh material - it's very easy in a text editor. Then put SD card back into UM2 and load your material settings from SD. 3) You can get the bed hotter than 100C if you enclose the machine somewhat. Put some saran wrap on the front of the machine. Put a paper copier box (that used to hold 10 reams) upside down on top of the machine - it will block some air and let some out - you dont' want the air temp to exceed 50C or your servos might die but 50C is safe enough. 4) For hips you probably want fans off - you can set that in material settings also.

yes - was posted in list of bugs somewhere on the forum.

No dual print. Maybe the ultimaker 3? But certainly not the UM2. Regarding bed temp - I had that on 2 different printers - 3 times for me now over the years. It was always easily fixed. Usually you just tighten down the screw for the temp sensor - on the back left corner of the heated bed - best to take it all apart first (remove glass - completely unscrew the 3 bed screws, unscrew the 2 cable hold down screws). Once I had to reflow the solder. But it was always very easy to fix.

That was a point on the list of improvements on the UM2 over the original - no electronics board fan. However the UMO+ has caught up with UM2 and now that has no fan either.

250C will wear out your PTFE much faster than normal temperatures. It will get soft and squeeze the filament and you will get underextrusion and then you will know to replace it.

I've never used hips but I hear it's quite difficult to work with. It wil clog your nozzle if you don't keep it moving constantly. You don't want it to stay hot for more than a small number of seconds: 10? 20? I would avoid it. Did you buy limonene to disolve it if you get a clog in the nozzle? Hips is a great material but PLA is much nicer in most ways. HIPS is now very popular as a dissolvable support structure. But you would need dual nozzles and you would have to be very careful about not letting it stay hot for too long. Maybe someone else on the forum has used it.

Oh! Now I understand - you sent the bowden throught the peek part also! No this is different, 3dsolex/Carl/Anders have a smaller inner diameter PTFE isolator and a smaller diameter olsson block and smaller inner diameter nozzles. So the bowden stops at the white part in the photo that Anders posted.

Two things you can do to relieve autoslicing stress: 1) Set your layer slicing height to 2mm temporarily until you get your object positioned properly and you are ready to truly slice. This will slice 10X faster than .2mm slices. 2) Get all your settings perfect before loading the model. I know - silly workarounds - but still...

Also temp sensors that fail drastically (more than 30C) can be working fine at 20C but still - make sure it reads 20C when at room temperature. But typically they work fine at 20C and only when you heat them up do the parts start to seperate and the resistance increases fooling the UM circuitry into thinking the temp is higher.

Yes - there are many other things that can cause underextrusion so test the above things and let us know what you find. Here's how to test temp sensor: ==== Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can fail high slowly over time. Meaning the sensor thinks you are at 220C but actually you are at 170C. At 170C the plastic is so viscous it can barely get out of the nozzle. You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU

Carl at 3dsolex is planning to sell an "inner bowden" to take care of that. I don't think this applies to UM2. As you can see in above photo the bowden is so far above the hot zone it should be at air temperature. There is a fan (not visible in picture) behind the head blowing air through the middle zone keeping the white ptfe cool and the bowden and so on.