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gr5

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gr5 last won the day on May 20

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About gr5

  • Birthday 01/01/1963

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    Ultimaker Original
    Ultimaker 2
    Ultimaker 3

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  1. gr5

    Consistent Feeder Grinding Issues

    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).
  2. gr5

    How do I make partial bottoms?

    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.
  3. gr5

    How do I make partial bottoms?

    So your model is a cylinder? But you want the result to look like the upper photo?
  4. gr5

    Consistent Feeder Grinding Issues

    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.
  5. gr5

    Consistent Feeder Grinding Issues

    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.
  6. gr5

    Consistent Feeder Grinding Issues

    It's not a problem of the polymer. The problem is viscocity, pressure, and the strength of the feeder. The feeder can only push so hard on the filament until it grinds up into dust. The UM3 feeders can push with about 10 to 15 pounds of force. Getting the filament with a consistency of toothpaste to go through a 0.4mm nozzle at 5 mm^3/sec at 230C requries a lot of pressure - around 1000psi. The UM3 feeder can't always achieve this (by the way is your feeder set to the middle position? you want it in the middle position). You say 235C made no difference but that's hard to believe. I'd like to see a print where the nozzles were at 235C or where you printed at half speed or half the layer height. It might not be perfect but it should have a significant improvement. In the UM3 tune menu you should be able to set the speed to 30%. And you should be able to increase the temp by up to 25C. I'd like to see what happens when you do that first. You could print for 5 minutes at a time with different settings all in the same print to get some ideas of how bad your situation is so I can get an idea if this is a hardware issue or just that you are printing too cold/fast. I'll give you some speed numbers next - from old experiments...
  7. gr5

    Scars on 3D prints

    Three thoughts: 1) retraction. Check the print in layer view and try to find these spots and see what happens there and in particular if there are any light blue lines in these spots which are retraction moves - you might need to play with the retraction distance. Retracting too much or not enough can cause spots just like these. 2) speed. Try printing at half speed - it's amazing how much better the quality can be. 3) slicer. Try cura 15.04. I'm not sure but it seems like some of these blemishes don't happen in cura 15.04. I don't understand why as it's the same slicer engine but some setting or something may have changed. Many people (many!) have had better luck with cura 15.04. However I have had excellent results with cura 3.X so I don't know what's going on. What kind of printer is this?
  8. 3dsolex sells a ruby nozzle for UM3. Look for "hardcore" which is their version of the UM core and "everlast" which means ruby. These nozzles can print 20 spools of CF filament with no wear. Woodfill should be fine with just an ordinary brass nozzle but each manufacturer is different and the size of the wood particles is different so look at what they recommend as the minimum nozzle size. 3dsolex also sells a 0.6mm core. The nice thing about the 3dsolex cores is you can just buy one core and change nozzles. disclaimer - I am the distributor for 3dsolex products in USA so I am a bit biased.
  9. gr5

    Sexy girl

    nice. Is this your design?
  10. Ooh. I wouldn't do that. If it's PLA and is at all old (has been on a shelf for a year before you got it) then this will ruin it. More info here: Basically if you even just straighten it and let it sit like that for a day or so it will be incredibly brittle and break into pieces or if it doesn't it will break going into the bowden. I think you just have to leave it alone on the spool and have a good powerful feeder. Maybe print 30% slower the last 1/3 of the spool. Maybe. Or get a powerful feeder like that on the UM3, the S5, the UM2+ or get a bondtech feeder. Or a medusa feeder.
  11. Contact 3dsolex - link to this thread - see if they'll send you a free ICE coated 0.8mm nozzle. The ice coating is basically teflon - nothing should stick to it. If you go over 240C it ruins the ice coating and maybe that is what happened to your nozzle? Or maybe it was never ICE coated. The ice coated nozzles look a lot like steel. They are darker and less shiny than uncoated nozzles which are quite shiny (like chrome). I found that I have to print about 10C to 15C cooler with my 3dsolex 0.8 nozzle than with my UM nozzle because of the RACE technology which has the filament going down two different paths through the nozzle and heating the filament more thoroughly.
  12. gr5

    Noob question about internal fillings...

    Oh that looks good. I think you did a good job in sketchup there. Congratulations. I still recommend you bail on sketchup if you have less than 100 hours experience with it. If you don't please please read that guide above. Also ALWAYS look at the part in layer view and run the layer slider up and down - pay particular attention to the bottom layer but also pay attention to possible overhang situations.
  13. gr5

    UM3ext can't start a print....

    You should call your reseller because they might be able to help you for free. Although you may have violated your warranty at this point (for this particular issue. I really don't know how that works so I'd contact them right away. Anyway you need the nylon to get to about 150C so that it is soft enough to pull it all off. If the core still works heat that to 200C and let it sit for maybe 30 minutes, then start with the heatgun as necessary. It takes dozens of minutes for that heat to penetrate enough to start removing chunks so go easy and slow. You went much too hot. But I doubt you caused any permanent damage yet.
  14. gr5

    Nozzle running through print

    Do you man the "plus" kit? If so you have to download new firmware afterwards because the "plus" feeder has a different number of steps/mm for the E axis than the non-plus. If you downloaded new firmware it's good to do a "factory reset" which sets all the steps/mm and many other settings back to default for that printer. Anyway, this link shows a good explanation of where not to plug the fan into by erin from fbrc8:
  15. gr5

    cad programs

    Oh and here is a good guide to pick cad software: https://www.gliffy.com/go/publish/5271448
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