gr5

Print slower. I know we all want to print faster but if you are patient you will be rewarded. some dimples can be fixed by tweaking the retraction distance as well but if these are where layers start then probably not in this case. There is a trade-off between speed/dimensional accuracy/beauty. If you want beauty you really need to print the outer surfaces slow. If you only care about dimensional accuracy you can't print faster. Once you get parts looking really beautiful then you can start learning tricks to speed things up. There are dozens of tricks. For example gradual infill, faster speeds on inner layers. No infill at all usually works quite well also - surprisingly well. thicker layers, wider layers/larger nozzles, no support, custom supports, etc.

yes. Okay so realize first that the pressure in the nozzle can easily reach 1000psi (7000 kpa). And the bowden tube on a UM printer or the actual compressive springiness of the filament acts like a spring. So if you are printing at given speed and the pressure is say 500psi and you slow down for a corner in a cube to 1/4 speed you want the pressure to correspondingly to drop really fast to 1/4 of the pressure so the filament comes out 1/4 as fast but because there is a storage in the bowden or in the filament or other parts of the printer, it takes a few seconds for the pressure to drop so you get overextrusion on corners (and on the z seam or any other place it slows down briefly). Does that make sense? The X/Y can slow down much faster than the extrusion pressure. But the solution isn't to lower the acceleration - the solution is to increase the acceleration so it doesn't pause so long on the corners. But the printer can only go so fast before it loses steps.

@cekuhnen - keep in mind that STL files contain only triangles (not circles) so the circles in your cylinder are broken up into line segments when exported from CAD to STL format. You can usually adjust how many line segments are outputted as part of the CAD settings. Too many line segments would be bad as Marlin doesn't like to print line segments much shorter than .2mm (a whole different discussion). But no matter how many line segments you have on the inner and outer surface of the cylinder the wall thickness will vary quite a bit around the 2.4mm you wanted. Oh I forgot - also cura insists on an even number of passes. So you can't divide the 2.4/3 and get 0.8. You have to divide by 2 or 4 or another even integer. So 2.4/4 would be .6mm line width. Try 0.6mm or 0.58mm and see how that looks in slice view!

I don't really get much of a z seam on my parts probably because I tend to print slow - usually 35mm/sec. The Z seam used to be where the printer changed layers and there was a pause while the Z axis moved. But now the Z axis is moved on inner layers only (infill or inner shells). But we still have a "Z seam". It's the place where you go from outer shell to inner areas. The problem is identical to why you get large rounded corners on a cube. The problem happens anytime you have to speed up or slow down the extruder. When you come into a corner the printer has to slow down for the sharp corner and the extruder slows down an equivalent amount but it's too late as there is already a high pressure in the print head so the extruding doesn't really slow down at the Z seam spot even though the X and Y axis do slow down. So you get overextrusion (and of course a corresponding amount of underextrusion right after although that tends to be spread out on a larger area). So one solution is to increase acceleration and jerk settings on the firmware because now the print head doesn't spend so much time at the corner. The other solution is to lower print speed such that, again, the normal speed and corner speed are about the same. Other solutions include fancy features such as "advance" which is disabled in Ultimaker firmware but it is part of Ultimaker Marlin. You can turn it on in Configuration.h if you make your own version of Marlin. It's not the best fix. It's a bit of a hack and it underextrudes the wrong amount on corners and needs to be adjusted if you later adjust printing temp (which changes viscosity) or if you change filament color or type or print speed and so on. Even then it's a bit of a hack. Anyway, the UM answer I suppose is to basically slow down the outer most printed shell. Anyway this issue is much less pronounced on my UM2 than most printers because it has a reasonable jerk value (20m/sec) and a high acceleration value (default is 5000mm/s/s) compared to most printers. And again, I tend to print slow. I'm usually not in a rush and I have several printers.

The 7/8 thing I suppose is that the quality comes out better if you are on the small side than the large side and nozzles aren't all perfect - some are smaller/bigger than nominal. But 0.8 works fine. In your case where your part is 2.4mm thick there is some small amount of floating point error. Try 0.79mm for the line width and it should work better.

The binary or the source code? The binary is available in many places including cura. when you download any version of cura you can select the machine to be um2go and then connect a cable between your computer and your printer and update it that way. Or you can download the tinkerMarlin version which is really good - better I think than the normal marlin here: https://github.com/TinkerGnome/Ultimaker2Marlin/releases Let me know if you meant the source code.

That's extremely common. It happens when you have a part come loose from the bed and at that moment the part is wider than it is tall. It gets dragged around like a hockey puck. If the part is taller than wide it simply falls over. The fix is to get your part to stick much better. Are you using blue tape? You have to clean the blue tape with isopropyl alcohol. Blue tape comes with a layer of wax so the tape doesn't stick to itself. It only takes a few seconds of cleaning with alcohol. Getting parts to stick well may seem like an art form but it's actually a science and you can have your parts stick really really well if you follow all the advice in my video:

FYI Ultimaker headquarters is in The Netherlands which is normally quite cold except for a few days per year. If the temp hits 35C they think it's a disaster of earthquake proportions and close all the businesses (kidding - a little) and shut down the cities. Just kidding - I don't think it's ever gotten that hot in The Netherlands. Plus they turn on the air conditioner when it gets up to 20C. They just don't like weather above around 20C. I've seen women bicycling wearing skirts (skirts!) when the air temp is 0C. No hats. Just a jacket. And not just one per hour - one with skirt or shorts every 5 minutes will zip by. The cold doesn't bother them so much. So although they test these printers at higher temps, they do that rarely I suspect. In other words, the "warm environment" testing could be improved.

Let's concentrate on the 35C issue. I stronglyl suggest removing the cover on the larger board under the printer, put a brick or a book or something under the printer so it is tilted (the printer can print sideways or upside down or any angle no problem - no difference - I used to think it would help with overhangs but it doesn't). and get some breeze under your printer - use a desk fan or window fan or anything. 35C is fine but you need more airflow I think. In other words 20C with no airflow is similar to 35C with a tiny bit of airflow is similar to 45C with a strong airflow - all should be cool enough normally (these numbers are basically guesses but airflow is almost more important than ambient temp). The part we care about is the 4 stepper drivers particularly the extruder driver. It has a temperature overload circuit which shuts off the extruder but only for a few milliseconds so you might not have noticed. If this helps then also consider lowering the current to the extruder quite a bit. Maybe to 800ma (default around 1250ma maybe). I think you can do that in the menu maybe? Maybe not. It's in the UM2 menu I think but maybe not in the UM3 - but there are other ways to set the current. Step 1 is to see if some fan blowing under there helps.

My understanding is that it's no stronger than a normal part but it's incredibly light weight and basically as strong as if it was solid infill.

The increase in diameter happens to me also but it's not a problem for me. I can still print just fine. Is your "third fan" working? The one in the door of the UM3 print head? You should have gotten a second AA core. Have you tried that to see if there is something wrong with your core?

Yeah I don't like the 0.8mm profiles. I recommend you start with the 0.4 profile and change line width to 0.8 and change layer height to whatever you want. However you can simply click that little "custom" thing next to the "recommended" box and then you can change layer height to whatever you want. It's pretty easy to do.

Well UM printers can print a volume of about 5 to 8 cubic mm/sec through a 0.4mm nozzle at 230C and the 0.8 has 4X the area so you should be able to push 20-30 mm^3/sec. So for example if you want to approach those speeds I would do: line width=0.8 layer height = 0.5mm (so thick!) print speed=50 to 75mm/sec If you multiply line width, layer height, print speed you get the volume rate of extrusion. 0.8 X 0.5 X 50 = 20mm^3/sec

The specifications appear to be extremely close to regular PLA when you look at softening temperature (it's around 52C - same as PLA), printing temperature, strength,etc. So I strongly suspect regular PLA print settings will be close enough until profiles come out.

Pretty good. I'd be happy with that. But there are a few things you can improve. The thing that bothers me the most about this print is those horizontal lines. That could be temperature fluctuations but if so it should be obvious by watching the temp while it prints it would have to fluctuate 10C. More likely it is the Z axis. What kind of printer is this? Does it have one z screw? two? If the printer is less than a month old then you probably have a crappy z screw, or z nut, or bearings. If it's older than a month then hopefully the z screw is just dirty and needs cleaning. What is happening is that Z movement is inconsistent. You sliced for .15mm layer height but the Z is moving too far sometimes and other times not far enough. On times when it doesn't move far enough you get overextrusion because there isn't enough room to put all that filament in a layer that is say .05mm thick but enough filament for .15mm thick. So you get a layer that sticks out. When the Z moves too far you get underextrusion but it doesn't look as bad. It's still there though. If this is a new printer and it's not an ultimaker you might need to replace some or all of linear bearings, z screw, z nut to some higher quality parts. These are not expensive parts.

I had the same idea 5 years ago but Daid (the guy who first wrote Cura - no longer working on it) pointed out that it's rare for two layers to be exactly the same. I mean this works great if you are printing cubes but anything really fancy like a cone - now what do you do? You want the infill to just barely touch the shell on every other layer now? It gets more complicated and it's 3d and slicers aren't very 3d - they try to do most of the work in 2d. Changing thickness layers is a feature in cura - it auto detects the slope (like the top of a sphere) and makes more layers there so the steps are smaller and larger layers when things don't change as much from one layer to the next. It's called "adaptive layers".

There are other ways to do this but buy default: Cura does not set the tempature. The printer does. You tell the printer what kind of filament you loaded (e.g. CPE, PLA, ABS, Nylon) and you can create different material settings in the "custom" menu if you want to create ones that aren't already built into the printer. Or if you want to change the values. You can set quite a few things including: fan speed multiplier, nozzle temp, bed temp, retraction distance and speed. There's even a temperature per nozzle so if you tell cura you have a 0.8mm nozzle the printer will see this when you go to print that particular gcode file and it will grab the temperature for the current material and the current nozzle. There's a way to set this stuff in cura instead. Or after the print starts you can change temperature in the TUNE Menu.

By the way - if you tilt those masks by say 45 degrees the resolution/quality will improve greatly.

I believe this is a recent cura bug. but even if they fix the bug the nose would be improved if you put a tower next to this print that is at least one layer taller such that after it prints each layer it goes over to the tower. This also allows the nose to cool a few extra seconds which can make a big difference. The tower base should be 20% as much as the height (a 5 to 1 ratio). You can even make the tower cone shaped or pyramid shaped as long as you keep the 5:1 ratio throughout. I have a file called cube.stl that is very handy. I can add it to cura at any time and using scaling feature make it any dimensions I want in cura. I sometimes add this as a tower next to a print that has a small top. Like your nose example.

Well you can create a second model that has the inner shape (in your example, a smaller cylinder) and you can load both STL files and you can have cura modify infill settings such that you have different infill settings inside the smaller cylinder than outside. And you can set one of these to use solid infill, and the other to use no infill. LIke in this video: But I don't think that will get you what you want. I'm not sure. You'd have to play with it. But the added complication is you would need to model the inner "cylinder" shape (which is not a cylinder in your "real life" examples) anyway. So at that point you might as well model everything. Anyway I think you are out of luck but maybe someone else has an idea.

okay well you need to separate out "doesn't work" into multiple categories or you'll never get anywhere. That gray print that looks kind of mayan to me has little or even zero underextrusion so whatever you were doing there is a LOT better than the very first photo of a print you showed that was white and red and was severely (<50% extrusion) underextruded. Okay maybe the gray print failed but not because of massive underextrusion. The red print just above was looking great for a while but then starts massive underextrusion. Rather suddenly. Something very strange is happening there. I would check that your 3rd fan is working - the one in the door that swings open. If that stopped working it would explain a lot. Anyway I'm going to give you a list of underextrusion causes for Um3. I think #1 may have caused most of the issue on your first white print but makes no sense for the red print. So let's keep looking. #5 is a good thing to check especially 5b. Actually just try changing coress. #6 worries me. You can ignore #9,#10 as the red print was fine at first. #16 worries me. #18 is likely the problem with the gray print. Maybe. It looks like it might have a lot of retractions with all the detail. I think the red print is a good one to concentrate on as it looks just fine at first down where the air is warmer. Also another thing that bothers me is extruder driver could be over heating which would explain the red print. Is the air warmish in the room where you have your UM3? Maybe take off the cover to the larger board and get a little breeze (just a little is enough but more is better) under there. Maybe lower the stepper current for the E axis down to around 1000ma. Or crank the AC to see if that helps. Did these issues get worse with warmer weather? CAUSES FOR UNDEREXTRUSION ON UM3 AND HOW TO TEST FOR THEM AND REMEDY THEM As far as underextrusion causes - there's just so damn many. none of the issues seem to cause more than 20% of problems so you need to know the top 5 issues to cover 75% of the possibilities and 1/4 people still won't have the right issue. Some of the top issues: 1) Print slower and hotter! Here are top recommended speeds for .2mm layers (twice as fast for .1mm layers) and .4mm nozzle: 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA. 2) Line Width larger than nozzle. In cura 3.X search in settings for all line widths. If any of them are larger than the nozzle diameter this can cause underextrusion. There are 8 of these in cura 3.2.1. 3) Curved filament at end of spool - if you are past half way on spool, try a fresh spool as a test. 4) curved angle feeding into feeder - put the filament on the floor -makes a MASSIVE difference. 5) Bad core. Try a different core. It could be clogged, or something more complex like the temp sensor in the core. 5a) clogged nozzle - the number one most suspected problem of course. Sometimes a grain of sand gets in there but that's more obvious (it just won't print). Atomic method (cold pull) is the cure - from the menu do a few cold pulls. The result should be filament that is the exact shape of the interior of the nozzle including the tiny passage to the tip of the nozzle. If it doesn't look like that you need to pull at a colder temperature. You can do it manually instead of through the menu if it's not working right but learn through the menu initially. 95C is roughly the correct "cold" temperature for PLA. Higher temps for other filaments. 5b) Temp Sensor bad - even the good ones vary by +/- 5C and bad ones can be any amount off - they usually read high and a working sensor can (rarely) fail high slowly over time. Meaning the sensor thinks you are at 220C but actually you are at 170C. At 170C the plastic is so viscous it can barely get out of the nozzle. You can verify your temp sensor using this simple video at youtube - on you tube search for this: mrZbX-SfftU 6) feeder spring issues - too tight, too loose. You want the tension such that you can clearly see the diamond pattern biting into the filament. You want to see at least 2 columns of diamonds. 4 columns is too much. You usually want the tension in the center. 7) Other feeder issues, one of the nuts holding UM2 and UM3 together often interferes with the feeder motor tilting it enough so that it still works but not very well. Other things that tilt the feeder motor, sleeve misaligned so it doesn't get a good grip. Gunk clogging the mechanism in there. ? Filament diameter too big - 3mm is too much. 3mm filament is usually 2.85mm nominal or sometimes 2.9mm +/- .05. But some manufacturers (especially in china) make true 3.0mm filament with a tolerance of .1mm which is useless in an Ultimaker. It will print for a few meters and then clog so tight in the bowden you will have to remove the bowden from both ends to get the filament out. Throw that filament in the trash! It will save you weeks of pain 8b) Something wedged in with the filament. I was setting up 5 printers at once and ran filament change on all of them. One was slowly moving the filament through the tube and was almost to the head when I pushed the button and it sped up and ground the filament badly. I didn't think it was a problem and went ahead and printed something but there was a ground up spot followed by a flap of filament that got jammed in the bowden tube. Having the wedgebot (link below) helps you feel this with your hand by sliding the filament through the bowden a bit to see if it is stuck. https://www.youmagine.com/designs/wedgebot-for-ultimaker2 9) Extruder mis calibrated. Maybe you changed equipment or a wire fell off. Try commanding the filament to move exactly 100mm and then measureing with a ruler that it moved 100mm within 10% accuracy. If not adjust the steps/mm (this is done by editing a json file on the UM3). 10) Z axis steps/mm. it's easier than you might think to double or half the Z axis movement as there is a jumper on the circuit board that can be added or removed. If the Z axis is moving 2X you will get 50% underextrusion. Your parts will also be 2X as tall. 11) Crimped bowden. At least one person had an issue where the bowden was crimped a bit too much at the feeder end although the printer worked fine when new it eventually got worse and had underextrusion on random layers. it's easy to pull the bowden out of the feeder end and examine it. Similar to 8b above - use the wedgebot to feel how much friction there is in the bowden. 12) Worn Bowden. After a lot of printing (or a little printing with abrasive filaments) the bowden resistance can be significant. It's easy to test by removing it completely from the machine and inserting some filament through it while one person holds it in the U shape. Preferably insert filament that has the pattern from the feeder and fight the movement by applying 2kg force on both ends at the same time and then seeing how much harder you have to push it on top of 1kg force. UM2 feeders can push with 5kg force. UM3 can push quite a bit more. 5kg is plenty. 13) Small nozzle. Rumor has it some of the .4mm nozzles are closer to .35mm. Not sure if this is actually true. I'm a bit skeptical but try a .6mm nozzle maybe. This shouldn't be a problem on the UM3 which has very good quality control but try a different core. 14) CF filament. The knurled sleeve in the extruder can get ground down smooth - particularly from carbon fill. 4 spools of CF will destroy not just nozzles but the knurled sleeve also. Look at it visually where the filament touches the "pyramids". Make sure the pyramids are sharp. 15) Hot feeder driver. I've seen a more recent problem in the forums (>=2015) where people's stepper drivers get too hot - this is mostly a problem with the Z axis but also with the feeder. The high temps means the driver appears to shut down for a well under a second - there is a temp sensor built into the driver chip. The solution from Ultimaker for the um2 is that they lowered all the currents to their stepper drivers in the newer firmware. Another solution is to remove the cover and use desk fan to get a tiny bit of air movement under there. This doesn't seem to be a problem on UM3 even though it's the exact same circuitry but they lowered the current in the firmware. But it's worth considering if air temp is 30C or hotter. It would probably happen only after printing for a while (air heats up slowly under the printer). 16) third fan broken. This tends to cause complete non-extrusion part way through a print. In the door of the head. You can hear it come on when cores get above 40C. Without this fan several things can go wrong. It can take a while as usually you also need several retractions to carry the heat upwards. There are a few failure mechanisms and I don't understand them all. One of them is probably that the molten PLA spreads out above the teflon and sticks to the metal in a core or fills the gap at the base of the bowden in UM2. Later it cools enough to keep the filament from moving up or down. 17) Spiralize/vase mode. This is a rarely used feature of Cura but you might have left it on by accident? In this mode the wall of your part is printed in a single pass. So if you have a .4mm core and the wall is .8mm thick it will try to over extrude by 2X. This is difficult to do and may instead lead to underextrusion. 18) too many retractions (this causes complete failure) - if you have too many retractions on the same piece of filament you can grind it to dust. 10 is usually safe. 20 is in the danger zone. 50 should guarantee failure. You can tell cura to limit retractions to 10 per a given spot of filament. Do this by setting "maximum retration count" to 10 and "minimum extrusion distance" to your retraction distance (4.5mm for UM2 and 6.5 for UM3).

I mean the quick answer is to model what you want - model a hollow cylinder instead of a solid one. It won't be as perfect as if you model a solid part and turn off infill but it should be pretty close. Then use default settings in cura.

So your model is a cylinder? But you want the result to look like the upper photo?

By the way once it grinds up like this you might want to manually push/assist the filament for a while until the feeder can get a grip on some better quality (not ground up) filament.

This is some old data from a UM2 but UM3 can't extrude much faster. These are absolute limits - I recommend printing at half these but a well tuned printer can print at these rates. This graph made me wonder if maybe you are printing ABS by mistake? If you put the filament in boiling water does it go completely soft like PLA or is it still just as strong as at room temp (like ABS)? At 60C PLA is about as stiff as string. It flops around under it's own weight. My other thought is maybe there is some abs in your core's nozzle that needs some serious cleaning from an earlier print. I'd love to see a photograph of the tip of the filament that you pull out of a core when doing an atomic pull (it's in the menu of the UM3 - I may have told you that - sorry if I'm repeating myself). I calculated these values by printing a part at 0.2mm layer height and 0.4 nozzle and 100mm/sec and then changing the print speed % in the tune menu until it was underextruding pretty badly (enough that the feeder was slipping) and noted the speed then tweaked the temperature and repeated. Then I converted the print speed to volume (line width X layer height X print speed). Illuminarti's tests are with a 0.65mm nozzle so they are harder to interpret for your particular situation.