gr5

most important thing - DO NOT LET HEATED BED COOL DOWN. Other than that you have hours/days to figure this out...

PLA doesn't absorb water. You don't have to store it very carefully. Nylon, PVA are the worst about absorbing water - keep them sealed with dessicant.

There is a lift switch calibration procedure you can run on the UM3. It's in the menu system somewhere. It sounds like you need to do this.

The algorithm works incredibly well for Ultimaker printers. It is making assumptions about the accleration and jerk settings on your particular printer. These are pretty high on (for example) the UM2 printer - 5000mm/sec/sec is the default acceleration. "jerk" is 20mm/sec (not true jerk - this is a weird marlin terminology). I think there *might* be a way to tell Cura what the acceleration is for your particular printer so that it calculates these print times more accurately. I guess you have to know how long a typical retraction takes as well? I suspect cura cheats and just has a certain amount of seconds for each retraction (versus knowing the E axis acceleration, max speed, retraction distance.

I'm pretty sure this is an issue with your STL file. Did you create this model? If you did you probably want to reduce the qty of triangles created when you exported to STL. When the triangles get smaller than around .1mm you start to get stuff like this. If you didn't create this then I would pass this model through meshlab and remesh it with quadratic decimation. It's very easy to do - one menu option possibly cut triangles in half or 1/4 and then click apply. More here: http://www.shapeways.com/tutorials/polygon_reduction_with_meshlab By the way I'm pretty sure you don't want support for this part - it's more trouble than it's worth. FFF printers can "bridge" just fine. The only overhangs you have are all bridged (supported on at least 2 sides).

I am very familiar with the "origin at center" issue but the way you describe it is unclear. 1) If you look at the gcode for the first layer, do about half the moves contain negative values for the X and Y positions? 2) Do you have a delta printer? I'm pretty sure you *don't* want origin at center but the information in your post could have confused me. It's mostly a feature just for people who own delta printers.

This looks like a prusa. Is the feeder mounted on the head (call it "head mount") or does the feeder push the filament through a long bowden (call it "bowden")? Well it looks like underextrusion briefly in one spot on each layer. and in a different spot. There are many possibilities, all of which can probably be fixed by the slicer. For one, what is your retraction distance? For head mount it should be something around 1mm. for bowden it should be more like 4mm. Having a retraction distance too long will cause this issue I see on your print. Also turn off acceleration control, jerk control, make sure "retraction on layer change" is off, make all the printing speeds (inner shell, outer shell, infill) all the same speed because when you speed up it can cause underextrusion like this briefly. You can turn all these features back on once you get things working/printing nicely. Try to match up these defects with exactly what is happening in slice view. I would reload the gcode file into cura to be sure you have the EXACT same one and try to find one of these holes and try to see what is going on. Cura lets you "play" the part one move at a time. Dark blue lines are travel moves *with* retraction. Light blue lines are travel moves without retraction.

3dsolex makes something called the i2k. I don't know if it's made from PBI or Polyimide or what. But it can handle temps well over 300C and it is like a small washer that you put between the heater block and the teflon part. Even though it's only about 1mm thick the temperature at the teflon drops by about 100C. So 100C on one side of the i2k and 220C on the other side are typical temps. I'm not a big fan of the i2k - it's just one more placed for filament to get hung up. But I've sold quite a few and people seem to like them. You should cut off about 1mm off the bottom of your PTFE. Anyway if you do this the PTFE will last much longer - probably decades. The wear and tear will no longer be from temperature but instead from, well, wear and tear (filament grinding it slowly away over the course of thousands of spools of filament). The problem with PBI, polyimide, steel and other things is that PLA sticks to almost anything if you melt the PLA and then resolidify it. So it's easy to get the filament stuck in the coupler. PTFE is one of those wonderful materials that PLA doesn't stick to. Because the i2k is only about 1mm thick it's kind of okay if PLA sticks to it because it's a small spot and you can power through it (the feeder can push with 5 pounds of force and break the filament free of it once again to start printing again). This is the same sort of design on the UM3 where you have about a 1mm long heat break made of steel. It's short enough that even though the PLA sticks there, the feeder can power through it and get things moving again.

Which size nozzle did you get? 0.6mm? If you turn off acceleration control on the UM3 AA 0.4 profile, those corners will get better but instead you will get something called ringing. The ringing will affect the physical size MUCH less than those corners but it will be easy to see the ringing pattern all over your part. Unless you paint it. Because UM filaments are shiny the tiniest change in angle shows up easily visually. so a 0.1 degree change in slope on your part is visible. And the ringing will cause this. But if you check for ringing with calipers you won't find anything. So if you hate ringing leave accel control on. If you don't mind it and hate those bulging corners, then turn it off.

Oh. And did you change profiles or settings when you changed nozzles? Some of the profiles that come with cura have issues.

I don't think this has much to do with the nozzle. This is a common problem with all 3d printers and can be fixed. The basic issue is that it slows down too much on the corners versus the rest of the print and so you get overextrusion on the corners. On the UM3 for example a quick fix is to disable acceleration control. That way it spends MUCH less time on the corners. Other fixes include increase jerk, increase acceleration, decrease print speed. Also for a part this small infill may be partly to blame - cura typically does infill at a higher speed than outer walls so consider making all the speeds the same. But this is likely not the issue. Another possibility is that your cad part has too many line segments on the corners. Cura slows down a lot if there are many line segments in a small space (say < 1mm). This is obvious if you watch it print - it basically stops on the corners. So... what kind of printer is this? Does your printer use a bowden tube? Does it use Marlin firmware?

flow is a parameter in the profiles. Cura comes with about 100 profiles and it's possible for there to be different flow settings for each material but in actuality it's always set to 100%. You can create your own custom profiles and have a different flow for each profile. You can name your profiles whatever you want such as "CPE PROFILE". Your method of measuring wall thickness with a caliper is interesting. The factors that affect flow the pressure on the feeder and material properties - how much the material slips in the feeder for a given pressure. The pressure is affected by printing speed and the viscocity and resistances through your feeder. Viscocity is affected by temperature. So the things that affect what flow correction you may want to use include: print speed layer height (affects volumetric speed of filament going through nozzle) line width print temperature material It seems like a lot of work to calibrate these but if you always print with the same layer height and line width and you always print with a consistent temperature for a given filament type then it's not too bad.

This looks like massive underextrusion. The base is fine because you are printing slower and so the filament can keep up but cura then speeds up as you go to higher layers and also turns on the fan. I'd say either the printer is defective or you are just printing too fast (or both). If this was a UM2 I'd say you probably need to change the teflon coupler as it is causing too much friction. I could be wrong - it would be helpful to see what this part is supposed to look like. Is it supposed to have lots of little vertical posts? Maybe you jsut aren't retracting enough or retrating too much. For a printer where the feeder is on the case of the machine and there is a bowden connecting the feeder to the hot end, you want lots of retraction - like around 4mm. for a printer where the feeder is moving with the hot end you want very little - like 1mm. Too much or too little retraction can cause prints like this.

Okay well it's happening all over the place but always at the start (or is it the end) of each hexagon so I guess I believe you (mostly). Do you have a feature called linear advance or something advance turned on in your printer firmware? That retracts a bit just before you get to a vertex that has a retraction or a major change in direction which would happen at the end of each hexagon if you have this firmware feature. WAIT - you said it happens at the START of each hexagon. So maybe the problem is that it is *not* retracting when it moves from hexagon to the next and leaks a little on the way so it starts out underextruding (combined with what looks to me like the head is a bit too far - I like to really really squish - much more than you are doing here). I'd try turning off combing for the first layer - something like "no combing initial layer". It's in the combing drop down I think. This will force it to retract when moving from one hexagon to the next and not leak any on the way. So I think it's a combination of 2 things: not retracting, head too far from build plate. Fixing either thing should fix this I hope. I know you disagree but when the filament doesn't stick it always means you don't have enough filament getting squished into the plate so it's either some kind of underextrusion or nozzle needs to be closer (or both).

Yes you have lots of choices. 1) UM2+ firmware will work as that goes the other way. You will have to adjust steps/mm most likely. 2) You can install tinker marlin - which I love - and which lets you toggle all feeder directions and adjust steps/mm in the menu. 3) You can swap the two wires in either (but not both) twisted pair. You just use a pin and push down on the angled piece of metal that holds the pin in and slide the pin out, then rebend that tiny piece of metal so it will start working again, swap the 2 wires and re-insert. You will probably need to change the steps/mm regardless. I don't know if the um2+ firmware supports that or not although there is an gcode to set steps/mm. Followed by M500 to save it so it still works after power cycle. So it might be easiest to do #2 above.

Okay. But what you see in slice view is what you get in gcode. So either your printer firmware sucks or you need to video it and watch one more time. Consider dropping the gcode into the website: gcode.ws which will show you for sure if it's supposed to be drawing the full circle. You can see travel versus extrusion moves quite clearly (although cura slice view shows it also - why trust cura if you don't have to).

You might need to clean that print bed (is it build tak?). But more likely you just need to move the nozzle closer to the build plate. Is this easy to adjust? On the UM2 you just turn 3 screws all equal amounts by hand and presto - the printer will be leveled perfectly for the next few months. It's hard to say how thick this bottom trace is but it looks much too thick. You need to SQUISH that bottom layer or you get just what we see here.

Was your core programmed as "hardcore"? You can switch it to be AA 0.4 if you follow these instructions (which is what I recommend) or you might be able to ignore these messages - not sure. But certainly changing it to AA 0.4 will get you going: First put your UM3 into developer mode - it's in the menus on the UM3. Your machine needs to be on your network (wifi or ethernet) if it isn't already. Once it's on the network it will show the IP address at the top of the main screen. Next you need ssh which is built into linux and Macintosh terminal but not windows. For windows I recommend putty: https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html In putty you don't type the "ssh" part but just put the ultimaker@111.222.333.444 part and click "open". ssh ultimaker@1.2.3.4 (don't enter 1.2.3.4 - enter the ip address listed on your UM3) username/password: ultimaker/ultimaker (much easier than root/ultimaker as it takes you straight into the utility to do sendgcode) Choose the type and size from the list below - T0 is left slot and T1 is right slot so before running any of these make sure the core you want to program is in the left slot if it will be AA and in the right slot if it will be BB After programming the core, slide it out and back into the slot at which point the UM3 will re-read the eeprom and realize it's new state. The software that does X,Y,Z offset calibrations for a core goes by serial number and that can't be changed so you shouldn't lose any calibration data when you do the below changes. AA 0.4 sendgcode M151 T0 A8 D7800000000004141 sendgcode M151 T0 A16 D20302E3400000000 BB 0.4 sendgcode M151 T1 A8 D7800000000004242 sendgcode M151 T1 A16 D20302E3400000000 AA 0.8 sendgcode M151 T0 A8 D7800000000004141 sendgcode M151 T0 A16 D20302E3800000000 BB 0.8 sendgcode M151 T1 A8 D7800000000004242 sendgcode M151 T1 A16 D20302E3800000000 AA 0.25 sendgcode M151 T0 A8 D7800000000004141 sendgcode M151 T0 A16 D20302E3235000000

This is trivial to fix on most printers - the problem is your nozzle is too far from the build plate. On an Ultimaker for example just turn the 3 screws CCW about 1/2 turn and this will stick just great. If this is a printer where you can't disable autoleveling then I don't have any suggestions.

This is basic underextrusion. There are many possible causes. Is this a UM2? Is this printer no longer brand new? If "yes" to both questions then I'd guess it's the teflon part in the printer. You need to replace that about every 500 hours or so. More often if you print hotter than 220C. I can give you a complete list of possible causes of underextrusion if you tell me what printer it is.

@KennethKenneth I don't understand what you are asking and I'm not sure that uncle_bob understands either. What does that mean? Maybe a specific example?

I have some of the green matte pla from protopasta. I wasn't super happy with it but I should try it again sometime. It prints like woodfill. I think maybe it *is* woodfill? So there is a high concentration of non-pla material so it doesn't stick to itself as well as normal PLA. At least that's my impression. So it doesn't bridge well. It probably doesn't overhang well also. And you need to do extra thick top layers to get the holes to fill in. At least that's my limited experience. But if you get it to come out right it does have an interesting look. Almost like velvet.

Meltink pla filaments based out of (I think) Florida is pretty good. Here's something I printed on the S5 using meltInk filament. I really love this color. Easy to print. Just your basic good quality PLA but with great color selection.

First of all - all that red in cura xray view is a problem. Is it possible for you to merge all your parts into one large part? if you have two separate solids touching each other then you have a shared wall. Cura does not like this. The STL file is a list of unordered triangles. Cura intersects planes with the triangles (slices it). Each slice generates a bunch of *unordered* line segments. The key here is that they are unordered. Cura then tries to link these lines into loops. Because of floating point errors when two lines are supposed to be connected at a point, sometimes the X,Y values of that point aren't quite the same so Cura has to fudge a bit and sometimes chooses the wrong line! Because of this - having two solids touching each other that have a shared wall can be a problem. I skipped a few steps here in the explanation. Let me know if I need to clarify this.

I still think the file was either severely corrupted or it wasn't a gcode file at all. Did you look at the gcode file yet? I mean with a text editor. It's a human readable text file.