gr5

Did you look at the gcode file? Just take a look at it.

Wow. That's going to be hard to do and even if you got it to work it would be pretty ugly. You would lose a lot of the resolution of the original part. There are lots of much simpler gcode viewers than cura. For example there is http://gcode.ws website which is written completely in javascript I think. You could start with that. cura is much more complicated.

What? You print the first object with the first nozzle and the other object with the second nozzle? It would be MUCH faster to print the objects as separate prints so it isn't heating and cooling nozzles on every other layer.

Also in your second photo - the blue one - you have quite a bit of underextrusion. You may have printed it too cold, or too fast, or maybe you need to replace your TFM teflon part.

If you are doing test prints expect to do 50 and so try printing much thinner parts and smaller parts. Maybe print *only* the "aul"? Try turning off combing. And try "ironing" as Sander said. Or at least turn combing off for the top layer (I think maybe that's an option?). Combing is a feature where, when doing infill (don't think top layer - think internal layer) if it needs to move say from one side of a "U" to the other, it takes the long path so that you don't get a string across the top of the U. That's combing - it follows an inter path. But the other thing about combing is that it disables retractions. So if you disable combing it will retract. Then you should also *maybe* consider the "z hop when retracted" feature. Normally that makes the quality worse but for your top layer it might help. I'm not sure. But really the IRONING feature should help you the most! it was invented by someone who makes lots of key chains. Similar to your prints!

The problem with the TFM is that it get soft after weeks at temperatures above 200C. So it looks fine now but if you compress it then it will squeeze the filament. That is why I suggested you drill it out *while it was still inside your printer*. The best way to test the TFM is to install it but remove the nozzle and slide filament through the TFM from below (while block is cold - <50C). There should be no friction from the TFM. The feeder can push with about 3-5kg of force - that's your budget. 5kg. If the tfn is using up 0.1kg then that's fine. But if the TFM is using up 1/2kg of your budget then that's a lot and will cause some underextrusion.

There's nothing wrong with doing that. I would recommend MIC6 aluminum which is a formulation designed to not-warp and is extra flat. But I'm sure it will be cheaper and easier to just get the free sheet from UM for your S5. I'm sure some 3rd party resellers like 3dsolex will sell aluminum plates for UM2, UM3 some day.

Oh Wait! Are you talking about the top layer of the green? I thought you were talking about the top layer of the purple! The top green layer is underextruded. Underextrusion on a UM3 is less common but it can happen. I would start by going through the menu and finding the cold pull option (atomic pull?) in the menu system and following the instructions. If you have some nylon filament that works extra well with cold pull but PLA works well also. I see you already changed cores. it could be the feeder. Did you print any glowfill filament? Or CF? Or other abrasive filaments? Here is a list of things that can cause underextrusion in UM3. You might start by looking at the infill speed carefully. Maybe cut that down by 1/2 or even by 1/4 just to see what happens. Maybe increasing temp by 10C. ============================= 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 roughtly 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).

Okay so I thought the problem was those bumps in the top layer but now I see they go down through all the layers and that's part of the model. So know I don't know what you are talking about. maybe you could zoom in more on the part? Try to get the light to shine off it just right to show us what you are talking about. What is the problem more specifically with the top layer? it actually looks pretty good but is a bit blurry.

I have seen something that looks just like that when I accidentally sliced for 0.6mm nozzle (and line width was 0.5mm) and used a 0.8mm core to print it. It took me 3 prints before I finally realized what I was doing wrong (I had sliced it and printed a few a week earlier and forgot that I had sliced it for a 0.6mm core). So maybe check your line width and make sure it is close to the nozzle size? Are you using cura? Maybe you need to go back to an older version. Are you using the neosanding feature? I can't remember what it is called.

Have you changed the PTFE/teflon part? That's the most likely problem. If that doesn't fix your issue I have a list of other things you can check but most likely it's the teflon part. They are considered an expendable. You should be changing it every 200-500 hours roughly. You can check how many hours you've printed so far in the menu system. You can get a few extra hours while waiting for the replacement part by drilling it out with a drill bit of size 3mm to 3.25mm. Without taking anything apart (just remove the nozzle and drill upwards carefully). You can also remove the nozzle and insert filament from below to feel the friction in that part. Also if you have never done a cold pull on a UM2 then read about how to do this properly or watch some videos of people explaining it.

If the Z axis was messed up then the part wouldn't be the proper height when you printed it. It would look all squished flat. That's not the problem. The problem is you are underextruding. How fast are you printing that infill? Cut the speed in half. You may have a defective printer. Have you ever replaced the teflon part? That is a consumable that needs replacing often. I know exactly what you mean about the nozzle hitting the layer below. I've experienced that mostly on the edges of overhangs but also if I print infill too fast (just like in your photo). You can slow it down from the TUNE menu while printing but expecit it to take at least 3 layers to recover and stop scraping the layer below so much.

@smartavionicsI think that's exactly what he did.

It's fine. I do it all the time on my UM3.

I'm not sure what you are asking - if you want layer height set to .05 then just set layer height to .05. Done. You definitely want to lower the nozzle temperature a lot. If you are printing .05 layer thickness consider printing at around 180C for PLA and cooler if your printer can do it. It seems silly to have the nozzle width 8X the layer height. (.4/.05). How about using a .25mm or .15mm nozzle? 3dsolex sells .25, .15, and .1mm nozzles that work on most printers (standard 6mm thread).

There a few ways to do this. 1) The way you mentioned works pretty well. Even though the pattern is "cross hatched" if you print it properly there should be no "grain". I know that higher temp materials like ABS often have a grain but this just means you need to learn to print ABS hotter. But I think you will like method 2 better: 2) Sometimes I model "needle thin walls" in my print. model an internal cuboid inside your part that is thinner than paper. Vertical walls so the slicer can't miss them. Walls that don't reach the outer walls. Imagine vertical pieces of paper - only as tall as you want your "ribbing". But hollow instead of solid. Hollow walls inside your part. Radiating out from your screw holes. You can model groups of these walls. Make the width tiny - say .01mm. You can put bundles of these radiating out from your screw holes. .01 is so small it will be filled in. So the printer will do "shell" around these "hollow walls" and create the structures you are looking for. Space the walls at least 2X the nozzle width apart. This will control the direction of "shell" lines in your ribbing so you can make them radiate outward and avoid that cross hatch pattern. This will work on any slicer - not just Cura. The height of these walls will control the height (inside your part) of these ribbing structures.

Something to do with support structure I imagine. Well you miscommunicated the part about "walls are straight all the way up". Now that I see them they bend over at the top. But I see the glitch you were talking about better now. Also it doesn't seem to be printing the holes maybe? This is very strange. I've seen a lot of weirdness in Cura but this one is new to me.

The "fat corner" issue is better fixed by increasing jerk and acceleration (if your printer can do that without losing steps) and also by lowering the speed by a lot. Try cutting speed in half. The UM3 can indeed take much higher acceleration than the defaults but you will get a new problem called "ringing" but if you care about tolerances more than looks, then ringing shouldn't bother you at all as those are basically not measurable with a micrometer but are quite visible to the eye if you shine the light just right (not hard to do at all). In fact you could just uncheck "acceleration control" and "jerk control" and those corners should get really nice. Or cut the print speed in half.

First of all - be aware that it will print what you see in layer view - so don't even try to print that. Try looking at it in xray mode. Are you sure there aren't other walls out there? That looks so strange. Can you show a photo of the model in xray and also normal view?

That would be a great idea. I know right now they have a supply issue with the plates but once that is straightened out - maybe there will be what you ask for. It seems reasonable. If not some 3rd party reseller (like 3dsolex) will probably come out with such a thing.

I really hope you publish your stress/strain graphs. I'm very disappointed that these manufacturers publish the modulus on their material but not the graph. The curve looks nothing like metals - there is no obvious elastic region (straight line on the graph) that transitions to a plastic region (more curved). Instead, it's almost all curved so the tensile modulus is really only relevant and useful in the first 5% of the graph. It's a bit misleading. So if you just plugged only the modulus and yield strength into software that calculates where a part would fail - PLA and these other plastics are actually MUCH stronger when used for example as a beam because they bend more than you'd think such that they are tougher than you would think. When people try to get the modulus through the flexural method you get a different answer, probably because of the curve shape. In theory whether you measure Young's Modulus through the tensile method (your bow ties) or the flexure method (like breaking a pencil) you should get the same result but in practice you get different results. Not that it matters much as engineers usually design well beyond where something will break. Having the entire stress/strain graph is much more useful and interesting.

The editor got strange so I had to start a new post... 2) 8mm versus 10mm deep shouldn't make much difference. I think it's a waste of your time. You should hopefully get the exact same results regarding tensile modulus, ultimate strength, elongation at break, etc. Hopefully you have a proper stress/strain tester. If not you might want to build the one I built for about $200 in parts. When calculating modulus and strength you are taking into account the cross sectional area of the part. So the 10mm part will have a larger cross section and be stronger and it should all work out. In fact any errors between the two results are probably air gaps - areas of the part where there was air instead of plastic. 10mm should be more accurate. But at some point the part is too strong for the machine doing the testing. I do about 6mmX6mm area because my machine only goes up to 300 pounds force and my parts tend to break at around 100 pounds force (sorry for the imperial units - I usually think in metric but sometimes...). 3) You might want to print some parts vertically but really, if your results are different than horizontal by more than 10%, well then you aren't printing the part right. Nylon and ABS and PETG don't always have good layer bonding and you need to turn the fans down to the lowest setting or probably off and also cover the front and top of your printer when printing everything other than PLA. 4) PLA has a property that you won't be able to measure with a normal machine - it bends with time. So if you make a chain link and hang a heavy weight on that chain link, over many months it will stretch out - it will "neck" (it will get thinner) more and more until it breaks. It might last a month, or it might last a year, but for brutal environments (marine?) where it is under constant load, PLA is not the best choice sometimes. Anything other than PLA should be fine. Like nGen/PET. So if you use it on a boat to hold a door closed (a latch) pla is fine. If you use it as a part in a winch or a cam cleat it will fail if it is under a calm but steady load for weeks at a time.

I agree that brands don't matter that much after testing many different materials. I built my own strength/strain machine that uses these "bow tie" parts to test. It agrees with the published data pretty well. A few thoughts. 1) For the tensile test - infill will make a HUGE difference. Also when I build these bow ties I set shell/wall width to 1 meter to be sure it's 100% shell and not cross hatch infill. This way the filament "grain" won't affect the results. For ABS if you print the bow tie vertically and if you aren't an expert at ABS layer bonding the part will be much weaker when you pull it apart (ultimate tensile strength). But this infill on tensile parts is not interesting to mechanical engineers. Normally you don't need 100% infill to make a part stronger. normally it doesn't help. Take a beam for example. You can drill lots of holes through it "sideways" without hurting the strength. So if you are going to test different infill patterns you shouldn't be doing these butter fly tensile tests but instead maybe you should be doing flexural testing. In flexural testing the infill pattern shouldn't make much difference on a beam. In other words I suggest you *always* do 100% infill and don't do it at an angle, do it with walls set to 1 meter so it's a concentric infill.

top image I think is what you mean by "left unit" and bottom image is the "right unit". In cura type "speed" into the search box and it will show *all* speeds, not just ones that are normally visible. Make all the speeds the same. I think the cororing is because it is printing different speeds for infill versus shell.

Even on the bottom layer? By default I think it doesn't reach 100% until the 8th layer. By then your getting into the "easier" area of the print.