gr5

So if you go back even older, the first few thousand UM2s had a very very quiet 3rd fan. You really can't hear it. And it works just fine. So consider just buying 2 for your older UM2s: http://www.digikey.com/product-detail/en/MC25060V2-000U-A99/259-1573-ND/2757803

Well my other suggestion is to avoid Nylon for your first 100 prints and just print PLA and become an expert with that first. PLA is the most popular material because it is the easiest to print and meets most mechanical requirements for most needs. Nylon and ABS are more difficult to print because they harden at a higher temperature which means they warp more. You should put a front door and cover on your machine for Nylon as well (but not for PLA). Also, because of this higher hardening temperature, Nylon is often very weak with bad layer bonding if you don't know what you are doing. You really need to enclose the printer and on a UM3 set the fan to around 1% to 3% which cura doesn't do. And you need to keep Nylon EXTREMELY dry. A dry winter is not good enough. You need to re-bake it often and you need to keep it in a bag right up until the last second as it goes into the feeder and so on. It's a tricky material but once you learn all the tricks you can make beautiful, accurate prints with it and they are tough. Very tough. But if all you need is tough then there are other materials. Or if all you need is higher temp sensitivity there are other materials. These can be printed but you have to watch the entire video and practice a bit. And maybe watch it again until you really get it and believe it - particularly the "squish" issue. No more automatic leveling if you want parts to stick well.

Contact your reseller. Although it could be as simple as a cable came loose underneath the printer that connects the two boards together.

Oh that sucks so much more! I assumed it was PLA which softens at a much cooler temperature. You will need even more patience. How does it happen? Well while printing the part gets loose and the head starts dragging the part around like a hockey puck and the nozzle keeps extruding but there is nowhere for it to go so it goes back inside the head. All that rubber helps. Sometimes. But not this time. The solution is to NEVER let your part come loose like that. It helps to have a high bed temp - 100C will help it stick better. But that's not the most important trick. To really get parts to stick well watch this video. I'm sorry it's so long but there's lots of details to understand:

Is it still connected to aelectronics? Can you heat the blocks? Basically you need a heat gun and a lot of patience.

This is all true. But you can do it. It takes a while to learn ABS but people here can help you. It's possible to print a 200mm wide and 100mm tall ABS part on a UM2 or UM3 and have it stick to the glass AND have it not get peeling layers AND have it be nice and strong when all done. But if you can get away with PLA or nGen then avoid ABS.

Is this spiralize mode? aka cup/vase mode? Just curious. I assume not as if so it changes everything about my answer... Well I recommend a shell width of 1.6mm and a line width of 0.8 so double check that. Two passes allows for a better quality outer shell. Also I believe there is still a bug in the default AA 0.8 profile where it enables "retract on layer change". Make sure that is off as that could explain everything you see here. But really the most likely issue is speed - try slowing it down to 50% speed and if that fixes these "pin pricks" then slowly increase the speed (do all this in the TUNE menu while printing) until they come back so you know your top bump-free speed.

I agree with all your analysis. This all makes sense. Consider lowering the infill speed and using the "gradual infill" feature in cura to save time overall (faster print, less underextrusion). Anyway for setting tension with PLA, the example on the left is not tight enough. The example on the right is too tight at the feeder. Either condition can cause filament to grind up and cause a print to fail particularly when you have lots of retractions (sometimes on a retraction heavy print the same point of filament might go back and forth 30 times through the feeder)

The only difference to Marlin is the steps/mm. Some newer versions of Marlin let you set that in the menus. Or you can change it with gcodes and save that into eeprom. Since you can do it in gcodes you could use pronterface to send the gcodes one at a time (one for changing, then a M500 for saving to eeprom) or you can use a text editor to put the 2 gcodes needed into a text file, rename it a.gcode and "print" the file and that will update the steps/mm. So you don't need to modify marlin. Just change steps/mm. Also note that Marlin can only put out 40,000 steps per second (on all axes at once) so on a Ultimaker original, 2 or 3, if you go from the current 16 microsteps to 256 microsteps, the top speed will go from 500mm/sec down to 62mm/sec. Unless the driver has an interpolate mode (some do). But things won't be as smooth in interpolate mode with Marlin's "quad stepping" feature.

Most (maybe all) of these tests were perfomed on a printed part shaped like a bow tie but they were printed by different companies and using different printers. The UM filaments were all printed by UM so you'd have to talk to them, lol. Mostly each manufacturer printed the parts and sent them off to be tested or they had their own machines. Anyway each company chose different nozzle sizes and layer heights and so on. I've printed these "bow ties" myself and the best results come when you make the thickness a ratio of the nozzle width and you do all shell (no infill). Thick layer heights (e.g. 0.2mm or more) and large nozzles (0.8) might give slightly stronger results but I suspect most companies used their default nozzle of the printer that was handy so probably mostly 0.4mm or 0.5mm nozzles. More data to come! Watch this space, lol.

Oh - and NEVER print anything before looking at it in slice view in cura. That would have saved you a lot of wasted time and filament.

Is it still a solid? I suspect somehow you turned a solid object into something not manifold. Maybe a picture would help. Try looking at it in xray view. Anything red or brown is a problem (probably the whole part). Manifold means all the triangles in the STL connect together into a surface that encloses a solid. Whereas maybe when you cut it you don't stitch it up? Or maybe the part's walls are too thin to print? A think a picture would help us understand what is going on.

The nozzles are not sold anywhere. UM considers cores expendable. I believe they make almost no profit on them (not sure though). The nozzles are standard M6 thread but much much longer than the UM2 nozzles or e3dv6 nozzles. So, no. I don't think anyone sells them. Well infill layers tend to be done at a crazy speed. Cura I think decides to print so fast that you get some underextrusion or slipping. I don't like that personally so I set infill speeds to the same as the other printing speeds normally. Is it possible that you printed CF filament or glowfill filament at some time in the past? And now the gnurled sleeve of the feeder wheel is no longer pointy and is now smoothed out a bit by the filament grinding the points down? Just a thought.

I MADE A BETTER AND INTERACTIVE GRAPHS HERE: http://gr5.org/mat/ Okay well this post will grow when I add temperature properties. I've been thinking about posting this for a few years. Here is a graph showing some mechanical properties of some common filaments. Please read explanation as this is a complicated subject. Click to zoom in on chart (click 3 times - first click zooms, second click jumps to actual image, third click zooms into that). Higher up is stronger. Farther to the right is stiffer (not steel). Both axes are logarithmic. Most data is published by various manufacturers. I have personally verified a few of these numbers with my own equipment. VERTICAL AXIS So the vertical axis is tensile strength. It's measured by pulling on a cylinder of material from each end until it breaks. Divide the force by the cross sectional area and you get the strength in psi (pounds per square inch) or MPa (mega pascals) for those who prefer metric (like me). Anyway this is kind of complicated because the materials towards the left are quite stretchy and long before their breaking point the parts are damaged. The point where it won't bounce back is the yield strength but I choose the ultimate aka breaking strength. Or whichever was higher (some materials actually start to get weaker again - like steel. Or PLA). Now the weakest material shown, PP is actually showing the yield strength - it is actually much stronger than you would think so this is unfair. But the machine that UM used to test PP wasn't long enough to test this value (the part never broke). HORIZONTAL AXIS This is the tensile young's modulus wherever possible (sometimes it's the flexural modulus which is close enough). This is tricky and complicated but for the most part indicates how stretchy/flexible a material is. So ninjaflex on the left edge has very similar flexibility to a rubber band. Most nylons (except shapeways) are much more flexible than PLA or ABS and this makes them very tough. Materials to the upper left will be tough as hell. In fact anything to the left of and including "nylon UM" can probably be driven over by a car and come out just fine afterwards. Or a tank. Or you can throw it against a brick wall with full strength or hit it with a hammer. Most of those materials in most shapes can handle it. Tough. Materials to the lower right are more likely brittle (hence glass is the most brittle). XT is probably somewhat brittle among filaments (I've never tried it). Materials to the right tend to be hard. The hardness scale and the modulus are closely intertwined. Things to the right are harder, to the left are softer. Specific Materials The table that created the graphs here is at the bottom of this post. Red materials above are for comparison and are not filaments. ABS is shown in green above - this shows how different people testing the same material get different results. Most of these tests (maybe all) were done on printed parts which will be a bit down and to the left of injection molded parts. Two different companies tested Taulman Nylon 645. With professional equipment and also got different values hence the two data points. UM=Ultimaker in the chart. XT is colorfabb. POMC is delrin. I'm very skeptical about nylforce CF specs. If someone wants to send me some I'll print and test it with my stress/strain machine. In the graph above there are a few points to keep in mind. Materials with low softening temp are the easiest to print because they don't warp much in the temperature range from this temperature to room temp. It's only about 30C difference. As you move to the right the yellow group of materials is a little harder - parts are more likely to warp off the bed so you need to learn some tricks. Maybe. They really aren't much worse. The orange area with ABS and other materials are tricky now for a few reasons - they don't stick as well to the bed, you are now getting into materials with layer adhesion issues so you need to lower the fans, the bed takes much longer to heat up - you really need to enclose the printer to raise air temp to around 35C to get decent quality. The red group needs nozzles that can go over 300C (no teflon please!) and print beds that can go to 150C and ambient air in the printer at 80C. So this requires special equipment. Also as you move to the right your materials can handle working environments of higher temperature. The green materials can't handle a car with windows rolled up on a hot sunny day (neither can a human for that matter). The yellow materials can handle this but can't handle boiling water. The orange materials can handle boiling water. SOFTENING TEMP (horizontal axis) In the graph above the horizontal axis is a mythical characteristic called "softening temp". For many of these materials in the green and yellow area I have tested them myself personally by sticking them in hot water. Above a certain temp they can be easily bent and when they cool a few degrees they stay in the new shape. That's what I call the softening temp but in reality this value came from HDT (heat deflection temp) or glass temp in other cases or functional temperature in other cases. It's a mixed bag. So it's very approximate! Normally you want the heated bed at a temperature a bit above this temperature such that the material is soft enough to flex a little and spread out the warping forces. PRINTING TEMP (vertical axis) Also somewhat arbitrary as some materials like PLA have a wide range of printing temps. Also variation in heater block design and variations in nozzle length, filament diameter, airflow touching nozzle, and more - affect what this temp should be. But it is a good place to start. Mostly I'm just showing that the red materials need special equipment to print them. The green, yellow, and orange materials can all mostly be printed by most printers no problem. In table below, take all values with a grain of salt. Especially temperatures. For tensile modulus notes read "horizontal axis" paragraph far above. For tensile strength read "vertical axis" far above. For softening temp - please read "softening temp" paragraph above. I've already fixed several mistakes in the table below but ONLY on the website - please go my website for better data! gr5 materials

@KTW 1) are you printing PLA or some other material? 2) Is the bottom layer sticking really well but the next layer up peels off of it?

Well you have a bunch of choices. Cura expects the units of the STL to be in mm. Not inches. But STL files are unitless. So one solution is to design a 25.4 inch cube (which will come out as 25.4 mm which is one inch). A second option is that when you save to STL, most cad programs ask what unit you are exporting in. Tell Inventer Pro that you want the STL to be in mm. This is probably the best solution. Finally, in cura you can simply click on the tiny 1mm cube and scale it up by exactly 25.4X (2540%) or you can tell it to set the height (or any of the 3 dimensions X,Y,Z) to 25.4mm.

Yikes. Well try a different USB cable and try using a different computer as well if you can. Also consider putting some kind of spacer (maybe some napkins) between the two ribbon cables underneath the printer. Some people bought a $5 (5 euro?) USB hub to boost their USB signal power and that worked for them.

I don't let the machine insert nor remove filament automatically ever. I just pull it out or slide it in by hand. And then if I changed material (e.g. pla to abs) then I tell the machine afterwards. Get the wedgebot - you'll find it the most useful thing to print for your UM3: https://www.youmagine.com/designs/wedgebot-for-ultimaker2 So did you get it sorted out? Did you have to remove the bowden at one end or the other? Did you have to take the feeder apart?

If you want to risk the part not sticking though you can just turn the 3 leveling screws the exact same amount - about 1/2 turn CW to pull it down, away from the head. And you won't get these bumps as bad. But if you go too far the part won't stick well to the bed.

Looks good to me. This is how I like to do my first layer as this way my part will stick very well. And this is the top of the bottom layer. The bottom will look much better. What you are seeing here is some overextrusion on the bottom layer. Which again, is how I like it. Believe me, having a part like this come loose, and having it slide around like a hockey puck following the print head around, and resulting in molten PLA getting inside your head and then cooling and creating a massive glue bomb inside the print head - that's much worse than the bottom of your part feeling a little rough.

If you decide to "clean out the cura folder" make sure you delete everything in %appdata%/cura/3.1/

I'm not sure but I think maybe blinking red/orange when heating or cooling. Possibly white (or light blue) when at temp? Definitely blue when it's safe to take the core out (around 40C or cooler). I don't know the full answer. Hopefully someone else does.

If 60C helps then I suspect 40C will be plenty warm enough. There is a transition around 35C where PLA flows into the plate better. Temps above that transition don't improve much. Except that the softening temp of PLA is around 52C and being above that allows the PLA to flex a bit when the upper layers are contracting and trying to pull it off the plate.

Did you try setting shell to a high value such as 200mm? For the part above it will improve the pattern especially where I assume the part is weakest (in the middle). Anyway - so this is how you get what you want - but you might not like it. In CAD create several - maybe about 6 - thin wall shaped holes through the part. So it's like a long slit that goes from nearly one end of the part to the other end. The thickness of this slit can be very small - say 0.01mm such that in reality there is no gap (the filament is all touching across the slit). And set shell to a high value. These two things combined can get the pattern you show above. Was that clear? Or was that confusing?

Try sending it to shapeways or 3dhubs. You can get it to print a little faster but not much. Send it out. It's very easy to upload a model to either of these sites and get a quick quote.