gr5

So 0.3mm layer height is quite thick for a .4mm nozzle. I would seriously consider printing this with a .8mm or larger nozzle. If you multiply these 2 numbers and also multiply by speed in mm/sec you get the volume per second. so for example 100mm/sec print speed X .3 X .4 gives you 12mm^3/sec which is too fast for a UM printer. Even if you heat PLA to 240C nozzle temp such that the PLA is less viscous - that's a difficult speed to print at with such a small nozzle. I wouldn't go over 30mm/sec with that thick layer height. Otherwise you will likely get some underextrusion.

https://www.mosaicmanufacturing.com/

There's a company called Mosaic that does this in an automated way with a filament splicing machine controlled by the computer. While you print! It works pretty well. But it only works on 1.75mm filament. I think they tried it on 3mm filament and the color transition takes to long wasting tons of filament. So you would have to convert to 1.75mm filament if you bought this. 3dsolex could help you with that if you wrote them a nice letter (they could build and sell you 1.75mm cores to test out). Or I could if you lived in USA instead of UK. But converting a UMO or UM2 to 1.75 is quite easy.

Which printer? UM printers (UMO, UM2, UM3) use the Marlin firmware which doesn't control jerk but does control acceleration. You can increase the acceleration (I think the default is 5000 but UMO and UM2 can do 9000 usually no problem if you oil things) too much you will get missed steps. If you decrease it you will get smoother motion but the print will take longer. High acceleration (which gives you high jerk) gives you ringing (a problem for some people). But it also causes more even extrusion (corners don't bump out as much). Low acceleration gives you less ringing but takes longer and you get more variation on the extrusion such that infill sometimes fails and corners are thicker (bulge out) and a little after corners is underextruded. There are other printers where you can control jerk (it's a physics term - look it up on wikipedia) like the TinyG controller board. Actually I think that's the only company. They have a newer controller but I forget what it's called. Oh and I think newer printrbots has a tinyG or similar in it. But anyway I'm not sure why you care? The current accel settings on UM printers is set so that it prints just fine. Tell me why you care about jerky speeds and then I can tell you more.

Have you gotten the tour of the shapeways factory? There's one in NYC - I think it's in Brooklyn - I have been there for a tour. Interesting tour. I learned a few things. You can sign up for tours typically on meetup.com.

Price the part out at shapeways also. But beware it may take a week or two. You won't need to do much cleanup on those prints! They come out much better than an UM and you don't have to worry about support (but you can't have walls/columns thinner than 1mm). I would definitely not price this out at $5 even if you pay someone else $5 to make it. You have some skills and those are worth money.

Okay I don't think this is possible. That only work on infill. Not support. This is what I was thinking of: Also I thought you could break your model into two parts and have per-model settings set the support pattern but no. That's not an option either. You can certainly have more or less dense support on different parts of your model but not different support patterns.

zhop is probably unrelated to any of this. This is different from "retract at layer change". Check all the other line width settings and shell width. I like to make line width equal to nozzle width (e.g. typically 0.4mm) and shell width *always* a multiple of that (e.g. 1.2mm). Cura likes to make shell width 1mm and do one line at .6mm and one at .4mm or do two at .35mm and one at .3mm. It's a mess. I think it's better to stick with one size so that you don't have this adjustment period while the nozzle pressure returns to steady state.

Maybe. I haven't tried it but you can open a cube or cylinder with cura and scale it to any shape/dimensions then use that to alter slicer settings for your actual part. I'm not certain you can vary support settings using this technique but you probably can.

This is underextrusion. Very common problem. It is extruding about half of what it is supposed to be extruding. There are many causes but if you didn't change any slicer settings (consider printing an old gcode file that you *know* didn't underextrude) then it's probably the teflon part - that white part inside the print head. I recommend buying a new one or if you can't quite afford it you could remove the filament, remove the nozzle and just drill it out from below with a 3mm drill bit or a 1/8 inch (3.175mm) drill bit. Or a #31 (3.1mm) drill bit. Drilling it out will give you some more time but eventually you need to replace that part. There are other possible causes so if that doesn't fix it or if the problem is with slicer let us know and I'll give you the full list of possible causes.

You probably have to adjust the rear screw to be looser. I would start from scratch: put the rear screw at mid position - half way between all the way down and all the way up. Then start the manual leveling. The 1mm thing is just very rough so the head doesn't slam into the glass or clips during the real leveling. I also strongly recommend leveling such that the nozzle touches the glass (no paper) but not everyone agrees with me.

Quieter is always better. I suspect they don't need the tl-smoother but it would be great if you could do a before and after print with the SSS chips and let us know. If you live in USA and do decide to get tl-smoothers consider shopping from my store at thegr5store.com.

Yeah do what kman said. But maybe ignore about the pivot point thing - that's cad specific. For my cad (DSM) I put the two models on 2 different layers so I can turn off one layer at a time and export to 2 different STL files. Basically the x,y,z coordinates of the 2 stl files have to match such that cura knows how to put them back together.

I have only done maybe 8. I haven't done one in a few months. It's almost always difficult. I take things apart until I realize I can't get temp sensor out. Then I squirt some WD-40 into where the temp sensor is - basically where the wires come out of the block. Then I try taking a large/strong sewing needle and kind of try to pry it out. The brass is almost as weak as butter - it gets chipped away as I do this - I get the needle between the brass and the sensor (inside the hole) and pry. This bends the tip of the needle but I just keep going - try opposite side of hole. Sometimes it seems like nothing is happening and a minute later it's slid out enough to grab 1mm of temp sensor using pliers. If no progress in 2 minutes then I heat. I forget if I go to 180C or even hotter. Wait till the WD-40 stuff is "steaming". Then repeat but hold the block with pliers. BE VERY CAREFUL - if temp sensor or heater slips out the heater will quickly enter a run-away condition of full power. Turn off printer power immediately. You only have a few seconds (maybe 5 or 10?) before it heater will be glowing at 600C (that's if heater slides out -- if sensor slides out then you have much more time maybe a minute to cut power) Once you get pliers on it start with a rotating motion - hold sensor still (not by wires) and rotate the block. Slide out at the same time.

Is it showing a shadow of where the tower should be in normal view? You can change it's location. I may have had this same problem but it was almost a year ago and I forget what I learned about towers in cura.

One more thing that might help is use a type of nylon that is more flexible. Look at the tensile modulus (or just the modulus). The lower the value, the more flexible the material. All the filament sellers out there publish this. Taulman has several different (quite different) Nylons. I think Bridge is probably the easiest to print of the Taulman filaments.

Smaller prints are definitely easier as the warping/pulling forces are smaller. Nylon is definitely harder. I printed some 30mm parts last weekend and one of them came loose. Things that help me: 1) Lots of brim. I know you said you do brim but I do 15 passes. 2) 80C bed temp. Not sure if this matters. Being above the glass temp will make the nylon more flexible so it has more give and puts less stress on the corners that lift (make those corners round also if possible). But the nylon I use has a glass temp of over 100C so 80C won't help with that. But it does help heat the air more so the nylon doesn't cool as much so it doesn't shrink as much. 115C would probably be better. 3) Cover the printer. I put a box on top - just a normal box that used to hold printer paper. No modifications needed. No tape needed. And a plastic bag on the front of the printer held on with blue tape. Air temp gets up to 35C. 3) I re-wet the bed before EVERY Print. Try to remove 90% of that glue stick with a wet paper serviette. Rewet the glue before very print with a paint brush and rinse the paint brush after. 4) Squish. This is the most important of all. I level manually only (no auto level) and I level such that the nozzle touches the glass. No paper. This makes it so the nylon is squished better into the glass. Having said all that I don't think I've ever printed Nylon parts wider than 40mm. The raft really should work. But the original author of cura I think never printed ABS and didn't understand the importance of a good raft. It should be at least 2mm thick and it should have lots of gaps. It needs to allow stretching to alleviate the strain on the parts stuck to the glass. It should touch the glass in parallel lines and that should go up 1/2 way and then it should have parallel lines in the perpendicular direction. I think older slicers (> 4 years old) do a better job with raft. google around for other materials. I don't remember what's supposed to work with Nylon (build tak? PEI?) but some of these newer materials (not glass) I'm told work quite well. Blue tape works okay with nylon also but you need very wide strips so the tape sticks well to the glass.

Oh! I forgot about that! So if I'm going to mess with the json files on my UM3, I think I'd rather buy this cable and connect it to my laptop and just login through that and undo whatever I did to break it.

So "normal" leveling techniques leave things so that the above is common. But I have never had this problem and I've been printing for 4 years. Thousands of prints. My secret - get the part to stick like hell:

@shurik - I add a drop of oil every 30 minutes or so - did you try that before you did this pla-pushes-ninja method?

The ones from 3dsolex.com are excellent quality and good price. If anyone else needs to take out their temp sensor - it's very tricky but I know someone who removed 100 and only damaged one. The technique I use involves a sewing needle, WD40, and heat. They can be very difficult to get out without damaging. But never ever pull them out by the wire.

Note that in cura 2.* it's called "line width" now and of the above 4 settings 3 of them have multiple values (different line width, print speed for infill versus inner shell versus outer shell).

It's underextruding. Since I assume your printer hasn't changed from one print to the next it can only be one of these things: print temp print speeds layer height nozzle width Look at the old print job from cura 15 and write down the above 4 values and then set ALL the print temps, ALL the printing speeds, layer height and ALL the nozzle widths to what it was in cura 15 and see if that fixes it. If it does then please undo the changes one at a time and let us know which problem it was. The Cura team needs feedback on stuff like this (bad slicer defaults that lead to underextrusion).

All technologies including FDM and injection molding have weirdnesses like this (e.g. in injection molding if you want 90 degrees corners your cad part better not have 90 degree corners). I add typically .4mm DIAMETER (not radius) to all vertical holes. The cause of all this is that the filament sticks to itself while cooling and shrinking in a fraction of a second as it comes out of the nozzle and it's like sticky mucus (like snot). It's pulling like a liquid rubber band and pulling inward on these vertical holes. Horizontal holes don't need to be adjusted in diameter (but you might want to put pointy tops to the holes).

There are tricks you can do in cura. You can create a cube in cad or download one from thingiverse and place your model and the cube on the plate. Then you can adjust your cube to be larger in x,y than your model and 5mm tall. I'm a bit sketchy on the rest - there is a way to make the cube affect cura settings and also to put the cube on top of the part (some option in settings - not part of profile but part of cura basic settings - some checkbox lets you do this - have models be overlapping). Then you tell cura that inside the cuboid do support and outside you disable support. I've never done this but other's have I think so I'm very sketchy on the details. Personally I just do my own support designs in cad.