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Nico I haven't seen this issue. It's kind of weird. What's the initial nozzle temp? I'm wondering if it is taking a very long time to heat the bed and the nozzle is hot for too long? My computer with the CAD software and SD card reader is on a different floor so my workflow usually involves turning on the printer, setting build plate to 65C, then removing SD card and walking upstairs. By the time I get back to the printer the build plate is almost up to temp. So maybe it has to do with not heating up the nozzle above 180C for very long?

@leon - I don't know how much you are following things but UM is hard at work designing new feeders that won't have this issue. For example one of *their* new designs has the bowden slip much further in from the top so that the filament doesn't touch ABS after the gear and they added a metal gromet at the bottom of the feeder so it doesn't touch there either. This is still all experimental but you can request your own grommet and print out the current design if you want and they will send you a free grommet. Or you can print many other community redesigns. Ian's design: Ian? Where is it? Geek's design: https://www.youmagine.com/designs/extruder-um2-version-2

When the printer is not moving and the lights are on, poke your finger around the led strips until they flicker. That will be the problem area.

I recommend you disconnect the two skinny wires and measure the resistance between the screws. It should be around 108 ohms at room temperature. One screw should connect to one side of that tiny PT100 and the other screw should connect to the other side. If the resistance is infinite than one or the other signals is not making it to that PT100. Measure the resistance of the PT100 directly and then measure the resistance from each side to the 2 screws. Here's a table that converts resistance to temp for the PT100: http://www.intech.co.nz/products/temperature/typert.html

What the hell? You put the whole thing together in one day? It took me at least 3 evenings (I forget).

There are several possible causes but the most common is a bad connection in the temperature wire at the top of the print head. On the print head of the UM Original there is a small circuit board. One of the wires coming off that board goes up along the bowden cable back to the PCB. The wire there at the top of the head is usually the problem. Try pushing the head around to the 4 corners while power is off to the nozzle and see if the temperature jumps suddenly. Also try pushing and pulling a bit on that wire. It's supposed to go through the black delrin (delrin is a kind of plastic) "F" shaped strain relief. Does it? There is an extra, identical cable there for the second extruder that you probably don't use. You can swap to that wire and then also swap underneath so that you are using the new cabling. And make sure the cable goes through the strain relief this time. There are other possible causes. The second most common is having the thermocouple wires that go from the heater block to that circuit board being too close to the fan wiring. When the fan is on - especially when it is not at 0% or 100% the wires can act like an antenna and broadcast noise into the thermocouple wire which is sensitive. The fix is to keep the wires at least 10mm apart until they get to that chip on top of the print head. edit: I mean keep thermo wires 10mm from fan wires.

Because of the brim below. The brim and support on the same spot - well it doesn't work - it's basically a Cura bug. You could turn off brim. But I would instead model 8 1mm diameter supports for the 4 outer and 4 inner corners and let the UM2 bridge the rest.

Looks like black ABS from the feeder. If you take the feeder apart I think you will see it is getting ground up. Consider building a filament holder on the floor. I spent 10 minutes and used spare chunks of wood for this one:

Will imgur host your pictures for years and years? Or just a few months? It's probably better if you load your pictures into the forum so that they will last "forever" or at least a few years. Click "gallery" on the top left of this page, then click the "upload" blue button. Then when you make a posting click "my media" next to the smiley face.

The two thinner wires (white/brown) are for the temp sensor. The two thicker wires supply the power for heat. Double check both of those thinner screws since your problem with the temp sensor is likely either the screws or the solder connection form the connector to the board.

Daid is just providing information that there are better stepper drivers out there that are quieter. I believe Eric Zalm is working on a whole new Marlin with all new hardware. Possibly including these newer steppers. He doesn't work for Ultimaker as this is probably more for the reprap community but I'm sure UM will jump on this as soon as it's "product worthy". In other words, a few reprap people will get it first, but eventually maybe it will be in the UM3D or maybe a UM Original PCB upgrade or UM2 upgrade. Who knows! If you really need to know what the status is you should talk to him, not UM.

Yes. Exactly. After printing the first layer (or the whole part) if you pull it off and look at the bottom layers carefully and there are thick gaps between the infill pattern then less of the part is touching the glass and so it will stick (half?) as well. If the volume of air in the gaps is say 20% of the volume of a stripe then you are probably levelling the plate 20% too far away as a percentage of the first layer height. So if you bottom layer height is .3mm and gaps are 20% then you should get closer to the glass by .06mm. This isn't how I measure it. Usually I just use the paper, use a thick first layer (.3mm or at least .2mm) and it usually works out fine. If it is something very critical due to strong lifting forces I always use brim and make sure there are no gaps in the brim and if there are I abort the print and re-level. If you are too close to the bed then the extruder tends to click a lot. Usually I don't care but sometimes I abort and re-level. Once you get levelling close enough it tends to stay good for many weeks.

By the way - an extreme hack fix would be to stretch the robot vertically by 2X in cura "scale" feature, print with .4mm layers and set flow to 50%. LOL!

Easy fix! This is usually caused by the Z stepper jumper being wrong. I even still have a picture in my gallery of it Click on the image above and look at the red circled part carefully. You want yours like that. The right most jumper should be either removed or placed as shown in the picture so that it does nothing (connects the pin to thin air). I suspect your right most connector is in place like the 2 next to it.

I couldn't see the picture. It wants me to create an account on the fencing site. When I got to the part where it wanted my email I gave up. I would expect solid infill layers to shrink *more*, not less. I'm wondering if there is a different issue - maybe related to a heated bed or fan issue as I've seen that cause what looks like shrinking but is something more complicated. To post a picture click on GALLERY in the top left corner of this page. Then click the blue UPLOAD button. After uploading make a new post and click "My Media" next to the smiley face.

You can buy a new piece of glass - it is ordinary glass except that it is very thick - so it should be very cheap - probably only 10 euros. Any glass store will custom make this for you - they do this kind of thing many times per day.

Oui, l'axe Z est fort.

I'm going to be helping out at the local high school "science and technology expo" in 2 weeks. I'll be doing planetarium shows all day in a portable planetarium (I have done over 250 of them over the last 15 years). But also at the expo I will be loaning them my 2 Ultimakers (an Original and a "2") and they will be printing for 4 hours. I can't be at the booth so I need it to run very smoothly. I will be training someone this weekend. Anyway I spent all last Saturday redesigning the "stretchlet". I didn't like how the letters came out for the one created on thingiverse and the design that ultimaker uses is much more comfortable than most (it has no sharp corners that touch your skin) so I ended up doing the whole damn stretchlet from scratch using sketchup (designspark doesn't do text). Took me 10 iterations (I have the 10 reject bracelets to prove it) but now I have the perfect stretchlet/bracelet for the expo. Sander gave me the code that UM uses to make stretchlets and I stole the code they use to knock one off and print another. I printed 25 stretchlets unattended and they came out perfect. Now if you simply turn on my UM Original it heats up and starts printing stretchlets. No need to grab the PLA with tweezers - I made my own custom wipe with gcode. Sunday I spent all day in CAD re-inventing the local high school with all its false fronts and overhangs and details and Sunday night printed a replica of the HS. Will be printing that on the UM2 during the Expo (with a completed one nearby). That was my weekend!

Daid maybe you already do this but it would be nice to add comments in the gcode where bridging is occurring in case someone wants to experiment with a plug in like: over extrude or decrease speed, or increase speed, or over extrude for the first mm, then underextrude the rest, or change acceleration, or whatever.

Here's what I would do with the 3mm filament. Take some sheet metal and drill a 3mm hole through it. Then feed all the 3mm filament through it and see how many times it gets stuck. Then throw all your 3mm filament away. Or you can skip to the final step and save yourself some time. At some point you are going to throw it all away. It's just a question of how long it takes you to admit defeat.

Your issue is with the Y axis - motor is in back left corner. If it leans forward in sudden steps occasionally it is usually a loose set-screw inside one of the 6 pulleys for that axis (yes six! check the two on the short belt the hardest of which to get to is on the motor shaft). If it leans forward more gradually where every layer is missing just a few steps, then the problem can also be set-screw but more likely it is caused by a rubbing short-belt. While it is printing look to see if the short belt twists back and forth each time Y changes direction. If so it is rubbing. Move the pulley on the Y stepper closer to the motor - You have to take the corner cover off (just one screw), then remove the 4 screws that hold the Y stepper, lower the bed just below the Y motor so you can rest the Y motor on it and not pull too hard on the wires. Look at the distance from the pulley to the motor - you might have to slide it even closer - about 1/2mm from motor is usually good. Alternatively you could add 4 washers under the motor standoffs so the motor is another mm or so away from the wall. I'm not sure if the screws are long enough to handle another mm distance but probably will be okay. Also look for black dust under the Y motor indicating a rubbing short belt. Also push the head around with power off to see if Y axis seems to have higher resistance.

Nope. There are 3 causes but in fact the slicer path will be .4mm larger in diameter than what CAD shows to compensate for the radius of the nozzle of .2mm on each side. The causes: 1) Shrinkage as people said. It sounds like you adjusted your steps/mm to account for this so it probably is not an issue in your case. Having infill does *not* prevent shrinkage - if anything it encourages it, pulling the sides inward. 2) segments in a circle. If you print a circle with 4 segments the cad software is cutting through the circle severely. The more segments the closer you are to a circle but even with 20 segments you are cutting into the circle a bit. So unless you have 100 segments you will probably see some minor "cutting in" due to that factor. 3) viscoscity and stickyness and pulling inward by the nozzle. The PLA while it comes out as a string is getting pulled towards the center of the circle as the nozzle goes around the edge. This places the PLA more inward than desired. This effect is stronger on smaller circles (pulls in more towards the center). It seems like the slicer could do some kind of "pulling in" compensation which might change for different types of PLA, nozzle temp, fan speed. The factor would somehow get stronger for small circles and weaker for larger ones. Most people however just print critical dimensions twice. The first time for practice, then update your cad model to compensate and print again. After a while you can build up a set of rules of how much to compensate for your typical printer settings.

If you set shell thickness to less than nozzle width then it purposefully underextrudes. This is acceptable down to about 75% (shell 0.3mm) anything lower and you get ugly underextrusion and weak layers. And holes.

I think UM2 XY is quieter because of the mounting and because of the material used. Wood makes for a great sounds board - think violin, guitar.

That sounds wrong. That sounds like pillowing. Pillowing can usually be fixed with more layers. Please post a photo. Here is information about pillowing (post #10): http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=17300