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Yeah that link looks good. I have to warn you, some of these arrive without working. I'd guess 90% work perfectly but 10% failure is pretty stunningly bad. That's where the US auto industry was in the 1970s. The 90% number is of course pulled right out of my butt. These are good instructions here for building your own UM2 Marlin (link below). You don't have to bother with about half the steps because that is for simulation testing. Which you don't need to do. Unfortunately I'm not sure which steps those are. Once you have downloaded the source code as explained, look at pins.h or maybe it's capitalized "Pins.h". Not sure but it matters if you don't use a windows machine. Anyway, try to find the Ultimaker board in there and then swapping the pin numbers is pretty trivial. There's the direction pin, the step pin, and an enable pin. I think that's it. 3 pins (3 digital signals) that the "arduino" uses to control the chip. Oh - there's more - there's some pins to control the max current used by the driver. So probably a few more pins. Many other people have done this if you google with "site:ultimaker.com" to get results only from this forum and include "pins.h" and "driver" and such. Some of them listed the exact pins they changed (and some of them messed up the first attempt).

I was going to say it could be one of the 4 wires to the stepper but you said you switched to the other drivers and it moved so yeah it's definitely the stepper driver chip. Some people are really good with surface mount soldering and have the right equipment (speical hot pad, hot air blower, I don't know what else). I have been soldering electronics off and on for decades and consider myself extremely good at it but I can't do SMDs. Well I can do two pin smds only. Some people in this forum have replaced a driver chip. The older UM2s and UM2+ printers have a spare stepper driver for the second extruder. There is an extra connector for that second extruder. You can flip the controller over and see if the chip is mounted. The driver chips are lined up near the servo connectors and are large and square. Unfortunately Ultimaker stopped including these chips on the UM2 controller boards at some point. If you order a new UM2/UM2+ (same board) controller board from Ultimaker it will not include that extra extruder driver. Now if you are doing the mark2, you are probably already using that second extruder (E2?) which is unfortunate. If you don't care about the dual extrusion much then you could change the firmware such that the X axis uses the second extruder. It's just a few lines of code change in the file "pins.h" which says which pins control which servos etc. You could swap the ones between X and E2. I can point you to very detailed instructions on building the firmware. I'd do the Tinkergnome firmware. If you really want your dual extrusion to still work then your only option is to buy a chinese version. There are 2 flavors - one flavor has the exact same stepper drivers. The other has socketed drivers so you can (sometimes must if it doesn't include the drivers) choose your own drivers. Which is a nice option if you are into really customizing things and modifying firmware. The drivers would be "pololu" style drivers which you can google about if the board you order clearly has missing (but socketed) drivers.

40% doesn't sound dry enough for me. Look I could be wrong - I print a LOT of Nylon and the nylon and pva spools "look" the same although I rarely get them confused but still - I have strong associations between them. PVA might not need to be as dry as Nylon (aka PA6). So much of my advice, explanation is more for Nylon than PVA. But with Nylon, 40% at room temp is definitely much too wet. I suspect Ultimaker is hedging their bets in the MS description and I suspect it keeps the air usually closer to 20%. I left a humidity detector in a bag and 21% was just not dry enough to keep nylon dry for months. 16% seemed to be good enough. Again - I'm not as sure about PVA but I think they are quite similar. They both suck water up easily and quickly (quickly meaning a matter of hours, not seconds). Ultimaker has special formulations that do better at staying dry and I don't use Ultimaker Nylon much anymore (it is definitely better but I suffer with the cheaper brands). I do use only Ultimaker brand PVA. Also I read somewhere that it matters more what the "absolute humidity" is (not relative). My printing room tends to be cool but is probably warmer than Ultimaker Headquarters (they like it cold!) so Ultimaker's "40%" is probably dryer than most people's "40%" as most people are probably in a warmer building.

Looks like pretty bad underextrusion. It could be the feeder or the hot end. feeder To test the feeder, fight it. Use the MOVE command in the UM3 menu to position the filament well above the print core so it is free to move in the bowden and away from the print head. Then move forward and at the same time fight the filament with your hand by pulling it the other way. It should pull with 10-18 pounds of force (>5kg). If it's less than 10 then something is wrong with the feeder. Maybe you disassembled it and put it together wrong (a common problem). Or maybe the tension isn't set to the middle setting. Or maybe you printed CF filament and ruined the gear that pushes the filament through the feeder. hot end Make sure the front fan (not the side fans!) is spinning. Heat the hot end to above 60C and it should start spinning - open the door to make sure it's spinning. This is a common issue that can cause underextrusion. printcore Try a different print core. The test is to use the MOVE command to extrude a lot. Do it at the max recommended temp (or lower). So 235C. (250C is just too hot - don't print that hot except for weird experiments). In fact the 250C could be the problem - some of the PLA may have caramelized onto the inner wall of the nozle hole and be restricting it. You can scrape that out with something metal like a .35mm hypodermic needle. printcore test Back to the test: use the MOVE command and you should be able to extrude some filament and get it to the print bed in ab out 8 seconds. Less than 10 seconds you probably should fix things but 10 seconds is fine. 20 seconds? Serious underextrusion. Try a different printcore - your printer should have come with 3 printcores. It's okay to use a BB 0.4 with PLA. Try several cold pulls. Read up about them for non-ultimaker printers and also you can do them from the menu on the UM3 under maintenance I think. Consider buying a new printcore - Ultimaker considers them expendables like filament. Since you replace them less often than every 5 spools, they are "cheaper than filament".

Experts tell me you need to occasionally clean the flex plate with soap and water (but dry it completely) or IPA (isopropyl alcohol). No "glues" such as magigoo necessary for PVA nor PLA. Also they mentioned: as the PVA absorbs more water it sticks less. It looks like the color of the PVA is changing as you get higher in the print. Perhaps the outer meter was wetter? That doesn't make much sense as the outer layer of filament on the spool is probably at least 15 meters of filament and this looks like only 2 meters at the most. Wetter filament prints "snowier" and drier filament prints more transparent but I can't remember if PVA gets completely transparent - I think only Nylon does that.

At 30% humidity the spool should survive at least a day out in the open. Perhaps even a week but not a month. I have found that 20% humidity isn't enough to keep PVA or Nylon dry. 16% works nicely. I put about 1/4 cup or about 1/8 liter of desiccant in the same bag with the spool. I use "2 gallon" (8 liter) zip locks. I keep the desiccant in a small container with no lid. I recharge the desiccant about once per month when I see the color changing. Even with all that I occasionally have to dry the spool: for PVA I heat the bed to 60C, unspool just enough for the print (cura tells you how much you need), put that on the bed with the spool on top of the unspooled filament. The spool itself won't warp if it's at least 1cm above the bed sitting on the unspooled filament). Then cover the spool with a towel or similar (t-shirt?). The unspooled filament will dry within about 4 hours. To dry the whole spool takes more like 24 hours to get deep into the windings. Maybe longer. This procedure is mostly only needed for PVA and Nylon which absorb water fast. PETG should be kept dry but is not nearly as critical. abs, pla, ngen, tpla I find don't need drying ever and can sit out for years. PVA can become noticeably worse even just after 8 hours of printing in a 40% humidity environment. Often you will get bits of PVA all over the place. Usually it's fine. Don't abort the print unless you are certain it's a complete failure.

The PVA might be dry. You can tell because steam comes out of the nozzle as it prints. When it gets really bad you can hear it popping and hissing. A little steam is okay. I have an S5 and not an S7 and don't know much about that flex plate. But special care needs to be taken for the first layer. I asked some friends who have S7 and flex plate. We'll see what they say when they get up tomorrow. When printing on glass I always add a "glue". I wouldn't do that for flex plate without knowing more first. Did Ultimaker say anything about magigoo or cleaning the plate? Or glue stick? Oils from your fingers can get on the build surface and perhaps you need to clean the plate with alcohol, soap and water, or something? I really don't know but I'll let you know when I know more.

PLA is the easiest material to print with. PVA is not even close. It's going to always be at least a little bit stringy. In general you want to keep it dry. PVA starts absorbing water as soon as you open the bag and the manufacturers don't necessarily dry the filament (some even run their filament through a water bath to cool it rapidly) but Ultimaker brand PVA is usually quite dry. Within 24 hours of leaving the spool on the printer PVA should degrade. Brittle sometimes means it is too dry but I suspect not in your case. PVA is brittle even when it's at the perfect dryness. Instead - it looks like you printed PVA on top of brim. That is bad - PLA prints nicely on top of PVA but not the other way around. PVA does not print well on top of PLA. You need to increase the "support horizontal expansion" to a large enough value so it reaches the print bed. Only then will it stay on top of the PLA (because part of the PVA structure is anchored on the print bed to help hold it in place). 90% of the problems people have with PVA is because it got too wet. You can tell because you can see steam coming out of the nozzle as it prints. Do you have 2 gallon zip bags ready to store you PVA in? You need to do that ASAP. Just a few days in humid air and now you have to learn how to dry your PVA on the print bed. Also buy some color changing dessiccant - get a liter or so. I suspect you haven't had that issue yet and may not for a few weeks/months.

I believe Cura tries to access all your COM ports and network drives and also searches your LAN for ultimaker printers. Until it had admin access it probably couldn't get to one of those things and unfortunately locked up. Or perhaps you installed it as an admin and it couldn't update it's own config files? Just some guesses. I don't run it in admin mode.

Please post a photo. Also you originally posted in the "german language" section of the forum. I moved your post here.

Unmarked. Try again. Personally it seems like the person who marked the solution should be able to undo their own work.

You might not like this answer or you may love it - I think a workaround would likely be to set the infill to 99%.

I'm glad you figured it out. I was about to say "you have to sign out of cura - not sign out of the website" but then you figured it out.

I love this. I looked at your spreadsheet. I have a problem with it as it's "access only" so I can't change the PLA Diameter to 2.85mm (which is what Ultimaker uses). And ideally the radius and width would default to Ultimaker spool dimensions. I also love how you show your assumptions on the spreadsheet itself (but not in the image above). I moved this out of the ultimaker printer area and into "3rd party...". Is there a way you can allow people to edit the 3 yellow blocks only? Or create this as a javascript web page? But I do love this and hope to be able to use it some day.

What print core do you have selected? This sounds like possibly a normal thing if you are using the AA 0.25 core (although I suspect that is not the case here).

It's worth it for sure to invest in a 20 euro teflon spacer if you haven't changed that out in the last 4 years.

I have never messed with material profiles, but can't you just select "generic pla"? That's what I typically do. Or I'll even select "ultimaker pla" even if it isn't and either tell the printer that it's an ultimaker pla that was loaded or I'll hit the ignore button when it says the 2 materials don't quite match exactly. Anyway, Slashee, I'm 90% sure he's creating material profiles somehow. The UM3 has pretty much the same firmware as the S3/S5 so I would think they all import material profiles from the gcode file on the USB. I'm sorry I know very little about this. I have an S5 but don't create material profiles.

The above chart led me to Design Spark Mechanical and I just love it but your needs may be different than mine.

You can just fix the model for now - I mean it's pretty obvious to you, hopefully, what the problem is. Just remove any inner walls that are *inside* the model where there shouldn't be any "magic" walls. So I still think this is the best way to pick cad software. I did not create this but I think it's fantastic:

1) Make sure "retract on layer change" is off. 2) Also in PREVIEW mode, step through the extrusions one at a time and see exactly what is happening at this corner. Maybe even look at it with the repetier host gcode viewer. It's free and highlights every extrusion and movement with it's associated gcodes. 3) Do you have "coasting" enabled? 4) Is this happening right after layer change? If so maybe print outer walls last? Maybe you already are.

The feeder upgrade is probably the most important change in the "+" kit. If you want to go cheap you can 3d print the meduza kit and order the parts. Look for meduza um2 on youmagine.com. The meduza upgrade is almost as good as the um2+ feeder - particularly if you also print the iRoberti feeder on top of the meduza upgrade. Ender is cheap, yes. It's probably not going to last you 5000 hours of printing like the UM2 will (more than 5000 really).

If this were an ultimaker I'd look first at the fan that controls the hot end. 1) This could be several things though - it's possible cura sliced the model like this on purpose and the model has faults. If this is true you will see the exact same gaps in the PREVIEW mode in cura. 2) Z axis issues can cause this although it looks so damn perfect everywhere else. Z axis issues would be where the bed suddenly slips down a few extra layers. If your Z axis moves the head and not the bed then I would 98% discount Z axis issues based on how the print looks. 3) Most likely is what Greg said. Temporary underextrusion. So many possible causes from tangled filament to feeder to hot end issues.

Almost certainly an issue with the model. Are you by any chance using blender or sketchup? If so then most likely the problem is with "normals". Read about normals for blender or sketchup and how to fix them. There are other possibilities. Actually I think I see a more serious problem already. I can see your cylinders have walls inside the part. That's a no-no. You can't have walls *inside* a solid. Unless their purpose is to create an air pocket. That's almost certainly the issue. Most cad software will not let you create walls inside a solid like that. I'm guessing you are using blender or sketchup.

I think 20-25% should be (hopefully) enough for this area. Also you want a few "top skin" layers. At least 3 layers in the top skin.

Probably insufficient infill just under this? Not certain. Could also be minor underextrusion but I don't see any other underextrusion.