gr5

It's called a "head flood". There are 2 possible causes - your door might not latch well and it could flop open during a print. Or much more likely - your part came loose from the bed when it was wider than it was tall. The solution is to make it so that the part NEVER COMES LOOSE. This is harder than it sounds so I made a video. Nylon is particularly easy if you squish well and use wood glue (or other PVA glue as shown in the video). Also I like the bed at 80C for Nylon or even 100C but that's the least important detail. Squish is most important. Also it's important to replace the rubber silicone gasket that is missing on your print head. They are very cheap. Something like 5 for 5 dollars/euros. Also your fan bracket is cracked - plastic parts are also very cheap from ultimaker. Electronics and other hardware not so much.

Yes. Retraction helps.

So the problem is that the nozzle is too far from the glass in that spot. The way tempered glass is made it tends to be higher in the middle although it's usually made at least a meter wide and your slice of glass could be from the edge or the middle but for some reason I think Ultimaker always gets the center slice? Maybe? Anyway it's very common for the glass to be higher in the center. Like a mountain in the middle. When you level a mountain at 3 points (rear and front corners) you end up with the rear 2 corners very low. So there is too much space there. I would just raise the rear screw a half turn or so (CCW as seen from below). Or avoid printing in the bad corners because if you raise the rear too much then the center of the glass will be too high. The reason it was better before is because whatever leveling you had done before, you had that corner a little higher in the past.

filament tangle? God it could be so many things causing this underextrusion. The first thing that comes to mind is that you are simply printing too fast. Are you using the speeds and layer heights that came with the profile or did you make the layer height thicker? Or increase the speed? Or lower the temperature? It's okay to slow down but if you make the layers thicker or print faster that could be the issue. It might be barely keeping up on the lower levels, closer to the heated bed but as the air gets cooler it has more trouble. This is unlikely but quite possible. Below is my complete list for UM3 but the problems that fit your photo the best are #16 and #21 and #5 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. Note that your "print speed" may be 40mm/sec but it may be printing infill at 80mm/sec so CHECK ALL SPEEDS. 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. Simpler cold pull (3dsolex cores only - doesn't work on ultimaker cores because you can't remove the nozzle): https://www.youtube.com/watch?v=u07m3HTNyEg 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). 19) Brittle filament. Espciallty with older PLA but even brand new pla can do this. If you unspool some (for example if it's in the bowden) for many hours (e.g. 10 hours) it can get extremely brittle and it can snap off into multiple pieces in the bowden. It's not obvious if you don't look for this. Then it starts printing just fine and at some point one of those pieces reaches the print head and gets hung up somewhere and the printer suddenly stops extruding for now apparent reason. This usually happens within the first meter of filament - once you get to printing the filament that was recently on the spool it should be fine from then on. 20) The "plus" feeder can have an issue where the filament doesn't sit properly for one print and it permanently damages the arm inside the feeder as shown by this photo - the hole is ground down asymetrically: http://gr5.org/plus_feeder_issue.jpg 21) Filament tangle - the end of the filament can get tucked under a loop on the spool and this tangle can propagate from then forever to the end of the spool until you fix it. It will cause many many jam ups and slow then halt extrusion. Repeatedly. The fix is to remove the filament from the printer, unroll a few meters and respool and put back on the printer. Never let go of the end of the filament spool until it's in the bowden.

Well you could convert to 1.75mm filament. In your specific case - if you are printing a lot of 0.25mm parts - I think it's worth doing. 3dsolex sells a conversion core. It's a bit tricky since you have to change the bowden but really - after you've done it a few times you can swap cores in just 3 minutes. 3dsolex also has a 0.15mm nozzle and 0.1mm nozzle for that conversion core. I sell this stuff too. The existing UM3 feeder works fine for 1.75mm filament. Assuming 1.15mm per step calculation is correct (it sounds right) then with 1.75mm filament you will get 1.15*(1.75^2)/(2.85^2) or 0.43mm per step at 0.06 height (again - I prefer 0.1mm layer height - I'm not sure why I need higher resolution in the Z than I'm getting in X and Y. But maybe if I tried it I would have my answer 🙂

I think it's cancelled. I think all large makerfaire's are cancelled. They filed for bankruptcy I think just after the san francisco one a few weeks ago. Let's cross our fingers and hope they can figure something out. It sounds like the mini makerfaires are still a go.

I heard it's working in 4.0 and I heard a rumor it is fixed in 4.2 (which isn't out as of today). I don't use support very often so I hadn't noticed. Also I'm still on 4.0.

Please note that you can also get 0.15mm and even 0.1mm cores for the UM3 at my store (yes, I'm biased) or at 3dsolex.com. Printing at 0.25 and smaller nozzles requires lots of experimentation to get the settings right. I've printed some amazingly small stuff with 0.15mm nozzles. One problem is cooling - I had to print many objects so that each object had time to cool while printing the next object over. I think these were 0.1mm layer and certainly 0.15mm nozzle.

0.048 mm/step is what you came up with. Usually this is shown the other way around: 20 steps/mm However the actual value on the UM3 I think is 369 steps/mm (according to some json file in the firmware I just checked). UM2 is 282 steps/mm and I think the UM2+ and the UM3 are similar and have more steps than the UM2. The difference from what you came up with (20) and 369 is about 18X. I think it's because there are 16 microsteps per step so the actual value is probably 369/16 or 23 whole-steps/mm which comes out to 0.071mm/step. Your math seems pretty good but the effective diameter of the feeder sleeve is probably closer to 8.7mm which makes your formula work out. Anyway, 16 microsteps is about right - that's the same value used for X,Y and E for UMO,UM2,UM2+ and the Z drive for some of those is 16 microsteps and for some it's 8 microsteps. Anyway what's a microstep? Well you can look it up in wikipedia servo articles. Basically there are 2 sine waves sent to the stepper and you can change the phase slowly and get as many substeps as you want but the chips that Ultimaker uses in the UM3 I think only go to 16 microsteps.

The reason these topics are fragmented and rare I think is because most people (like me) don't experience them. It's hard to diagnose a problem when it doesn't happen to me even when printing at 150mm/sec.

Go to machine settings (prepare mode, top left click machine, click 'manage printers', "machine settings" And uncheck "origin at center". Creality has origin in the front left corner. So uncheck that or it will center your print in the corner. Also you will probably run in to this other bug if you have cura 4.1: set z speed to 40 or something reasonable - more info here:

It's almost certainly the bug explained in this other thread. set z speed to 40 or something reasonable - more info here: https://community.ultimaker.com/topic/28173-cura-41-pausing-at-each-layer/?do=findComment&comment=240384

Check these two parameters: support X/Y Distance (defaults to .7mm I think) minimum Support X/Y Distance (defaults to 0.2mm I think) Also look at the part in "prepare" mode (at the top of the screen) and rotate the part to look under that overhang. Is it red? If not then the "normals" in the STL file are backwards. "normals" in the STL file tell cura which is the outside and inside of the part and are used to figure out where to put support but not relied on so much during the slicing step when things are 2 dimensional. What CAD software did you use to create this? If sketchup then it's trivial to swap the normals on this overhang. Right click and choose "reverse faces".

pronterface is easier to use. I think there *is* a checksum on the end of every line sent through usb/serial. If so then pronterface does this automatically and I think you can see what is happening (I think it shows you the checksum). Pronterface is free and is here and has a command line utility also I think: http://koti.kapsi.fi/~kliment/printrun/ Note that G0 X1 Moves to position 1mm (1mm from left edge) but this is absolute so you then need to do: G0 X2 To get to the next spot. If you just keep sending G0 X1 it moves there the first time but then keeps "moving" to where it already is from then on.

I'd like to see a video of your printing homing. I'm trying to think of which of 20 things might have happened. 99% chance this has nothing to do with Cura. The most likely thing in my opinion is that the horizontal rod through the head that is parallel with the X axis is not sticking out the left block far enough to hit the limit switch. Push the head to the back of the printer until you hear it click. I'm guessing you want hear the click because that rod should stick through the left block enough to engage the limit switch. Also check if your two rods that go through the print head aren't perpendicular anymore. Push the print head around by hand to the 4 edges of the bed. As you do this, feel the friction - the 2 axes should be the same. Note the side blocks as you do this also and see if both side blocks reach the end at the same time or if one has a gap. If so you can fix this with the hex driver that came with the printer - loosen two of the pulley set screws, adjust the blocks, retighten - tighten the hell out of those set screws. Also try homing the head - go into the printer menu and home the head - does it go too far back? Push the head around by hand again and make sure you can hear the limit switch click before the head gets beyond the edge of the glass. Start a print - after it homes in the back it should come to the front corner and extrude/prime the nozzle. Does it print within 1 or 2 cm from the front of the glass?

Yeah - it turns out that is the speed of light in mm/minute. It also turns out that Marlin gets confused and doesn't limit it to the max Z speed for you machine. As it should. Probably some integer overflow problem. The fix is discussed in this other thread:

Increasing your layer height won't help as then you will need to cut the speed. Get a better printer? If this is an ultimaker then your printer is defective - if it's a UM2 series then you probably need to replace the teflon part which only lasts 200 to 1000 hours of printing. It is expendable. Like pencils. The easiest and best upgrade is to get a larger nozzle. Most 3d printers default to 0.4mm or 0.5mm. Printing with 0.8mm nozzle is double the width but 4X the area and you can print 4X faster volume (because it prints lines twice as wide so you can do one pass on the wall and you can print twice as thick layer height). What kind of printer do you have? I sell nozzles for most printers out there.

yes. Cura 15.X does this. You can download and install cura 15 and it doesn't interfere or affect or replace versions of cura 2.X through 4.X. Right click on the model in cura 15.X and there is an option. If the objects in the STL do not touch it separates them out. Unfortunately I don't think there is a way to save the STL files. So the more that I think about this, the less useful it seems. meshmixer might be your best bet for simplicity. Also check carefully on thingiverse, sometimes they have a "tray" stl file that has all the parts but in addition they have the STL files for each part separate. Sometimes.

Some non-ultimaker printers have temperature control for the ambient air inside the printer. I think when this feature was added they forgot to make it default to hidden for Ultimaker profiles. It just generates a gcode that is ignored by printers that don't have the feature.

Those ripples in the photo at left are underextruding. And it's over extruding I think on that left corner. What is happening is the printer slows down a lot for that corner and stops briefly and overextrudes then it slides to the right but it takes a while for the extruder to catch up and stabilize again. Make sure "retract on layer change" is turned off. Try printing much slower. That way the speed change will be less dramatic at the corner versus the wall - try printing 1/2 speed - see how much that helps. Most printers let you vary the "feedrate %" on the fly so you can try 5 layers at 100% and then 5 layers at 50% speed and 5 layers at 25% speed and experiment on this one part. And again - make sure "retract on layer change" is off. Also I recommend all printing speeds are the same and travel speed is super fast (like 200mm/s). So make sure infill speeds, wall speeds are the same. Speed changes cause over and underextrusion as well (speed up and it underextrudes, slow down and it overextrudes).

So the old method I know about doesn't work anymore. It only worked on a beta version of the S5 firmware. So then I tried to disable it by hacking the python code but after several hours work was unsuccessful. It needs someone to go through the code more carefully and is too much work for me. Plus when new versions of the firmware come out any hacks will have to be reapplied. If there are any python coders out there who want to look over the S5 firmware (it's just sitting on the S5 linux computer - yes there is an entire Linux computer on the S5), then there are people out there who would appreciate the ability to turn off auto leveling on the S5. People who absolutely need it due to the way they use the printer.

This is a common problem and super easy to fix. You need to either print 3 of these or if you only need 1 then put two towers - one layer taller than this part on either side. I have a cube.stl file I keep handy. You can click it and scale it to any cuboid shape in cura. So I scale it to be a little taller than my part and make two of them. Usually I do about 15mm on the base of the tower. Having the printer go over to the other 2 parts gives this part time to cool down. Make sure your fans are working well also. I like to position the towers such that when it's printing one of them, the fan is blowing on the object to be cooled as much as possible.

1500 is pretty damn slow. I like 5000mm/sec/sec for acceleration and 20mm/sec for jerk. The lower jerk and acceleration can mess up corners on things like cubes - it slows down too long on corners and leaves a blob. But lower accel and jerk usually help ringing - that much is true.

So I think you have your units confused. 1mm is about a 25th of an inch. It's about the thickness of a quarter. Do you really want to print something that small? You could fit about 20 of these things into a pea. If you really need to print something that small, well try checking "print thin walls" in cura. Also make sure you print at least 5 of them at the same time as you need to let one layer cool for a few seconds so if you print 5 that will give it a few seconds to cool one part while it prints the layer of another. If you are going to be printing a lot of things this small you should invest in a 0.25mm nozzle. Or even smaller. But more likely you are confused about how big 1mm is.

Did you try unchecking "acceleration control" and "jerk control"? For the most part, one shouldn't let Cura pick the acceleration nor the jerk. This is just an attempt to lower ringing on visible surfaces but keep acceleration high on infill. But it's not worth it in my opinion.