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gr5

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Posts posted by gr5

  1. 1) 45mm/sec is way too fast so you probably have an older version of cura and marlin that has a bug where it actually retracts slower than you request. Otherwise you would have serious trouble at 45mm/sec for retraction. When you upgrade your Marlin some day, lower that to maybe 20mm/sec.

    2) You still seem to be printing too high off the bed on the first layer. I'm not 100% sure but look at the picture I posted and look at your picture and the skirt doesn't look squished enough to me. I think I can see where you clicked the z and it looks kind of bad on that level.

    When you slide the paper in it should be easy to slide under but not so easy that you can't feel anything. You should be able to do it with one hand *pushing* the paper under (as opposed to two hands holding the paper very tight and sliding it under that way).

    Another way to think of it - slide the paper back and forth with one hand, lower the bed until there is no resistance, then raise the bed until you just barely feel resistance. Be careful not to push too hard on the screwdriver while sliding the paper as that moves the bed also and changes things.

    So you want the minimum resistance where you are sure there is a difference.

    Your pyramid doesn't look too bad.

    I'm not sure what the pausing is - but it might be the "z seam" which is where the head is sitting when the z axis moves. Hold one hand on the z axis while watching the print job and when you feel the z axis move pay attention to where the print head is.

    You can sometimes move the z seam by rotating the part but your part is symmetrical. But for example if you were printing yoda you could rotate the z seam to the back of yoda's head.

    You can sometimes improve the z seam by speeding up the z axis acceleration and velocity a bit (about double is safe). Or you can use other slicers which let you put the z seam in a random spot, or you can change the order of loops, infill, perimeter to try to get the z seam in an interior location. If you have double thick walls (.8mm), the inner wall is part of "loops" so you can do loops last. Otherwise if you have no loops you can do fill last.

     

  2. Transparent PLA's I hear are more difficult to manufacture and may have a narrower print temperature range. Anyway, temperature is the key here. Print something very simple - like a 10mmX10mm box that is 40mm tall. Make sure you print slowly enough that no layer is printed in under 10 seconds. Start out at 240C and print enough to see a good amount, then lower the temp to 230C and then quickly mark the current print height with a sharpie. Repeat until you jam or it stops printing (around 170-180C). Keep notes at the same time. Something like this test print:

    http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

    Then be a nice person and post your results in "the art of printing" section.

    Regarding your second question, this isn't the cheapest but it has excellent quality! Which is more important than price - for example if the diameter hits 3.1mm the filament will be larger than the inside of the bowden and will jam and you will end up throwing the whole roll away even if it only happens once every 20 meters:

    http://printbl.com

     

  3. Yikes - when you home it should move to the front left corner! If nothing else, your motors seem to be wired backwards which happens occasionally on one motor - but two? That's would be pretty rare.

    Well I would concentrate on the left X endstop. The right and rear endstops aren't critical to printing.

    Remove power, disconnect that cable, get an ohm-meter and check the resistance with the endstop in normal position and when you push on it. The open resistance should be well over 1Megohm and when closed it should be less than 5 ohms. You should be measuring at the white connector at the far end of the cable from the switch itself.

    If that works, then you can keep it closed and jiggle the wiring - especially near the connector - it should never drift from 5 ohms. If it does, jiggle more slowly and try to find where the bad connection is. Often it can be found anywhere in one of the 2 wires anywhere from the connector to the switch. You may have to replace the wires or there may be a bad connection at the connector or the limit switch.

    Next if everything seems fine, triple check that you connected the left X switch to the correct connector. It should be the 6th connector down. Ignore writing on the bottom of the ultimaker as some kits had the wrong text for the X limit switches.

    Next you could power up and measure the voltage at the 2 pins of the limit switch on the UM board. Don't leave power on without the fan for more than a minute. Make sure everything is cool before powering up again. The voltage on one of the pins is probably always ground and the other pin should switch between around 5V when the switch is open to ground when the switch is closed. Or maybe the other way around. If the voltage is drifting around then there is probably a badly soldered pullup resistor for that signal or it is completely missing. If you get this far and Cura wizard still can't find end stops/limit switches it's time to return your controller board. Quality control for these boards is lacking.

     

  4. The pictures are blurry so it's hard to see but it looks like the table isn't close enough to the nozzle on the first layer. At least that's what the skirt looks like to me but like I said, it's blurry. The first layer should be flattened a bit by the nozzle. It should be wider than it is high. This is more obvious on the skirt. Also it looks like you might be over extruding, but again, it's blurry. So to fix this you need to level better with a piece of paper. Make sure the nozzle is clean and not hot when you level.

    For example this looks good to me:

    gallery_67_16_3920946.jpg

     

  5. 1) I don't think there is such as thing as a regular 100k resistor. Do you have the EPCOS one?

    Just try it. Get the erikZalm source code. edit configuration.h (that is the longest step by far). configuration.h is very very well commented. Just read it and edit it.

    Then download the arduino IDE. Then follow directions. I think it was a total of maybe 4 mouse clicks to build the thing. It's really not a big deal. The instructions at the bottom of this page look pretty good:

    http://reprap.org/wiki/Marlin

     

  6. It's time to re-level your bed I suspect. I now do it before every print and if it hasn't moved it's trivial. But the bed tends to droop over time. Especially the front edge.

    Even if I *do* level I still watch while the skirt is printed - screwdriver in hand - and sometimes make tiny adjustments while it prints the skirt.

    A good skirt should be smooth and flat on top. If there is too much space the filament comes out shaped like a tube or string and doesn't stick well. If there is too little space - well on blue tape it can come out like above where there are spots with zero filament and spots with blobs coming out. On flatter surfaces (glass, kaptop tape, aluminum) it basically just doesn't come out or is so thin it's barely visible.

     

  7. There's three possibilities I think. Either the steppers skipped as illuminarti suggests which would probably be fixed by tightening the set screws (all 6 for each axis). Or the plexiglass may have moved (I doubt it) or the 3rd possibility which I think happened here is that the frisbee came loose off the bed. You should be able to tell better than us if this 3rd possiblity happened. In your photo it looks like the frisbee is off the blue tape and outside of the normal build area. Also it's very rare for X *and* Y to slip at the same time (same layer).

    Large parts have a tendency to warp and the edges lift slowly off the tape. This would be the worst when you are printing the underside of the frisbee (the top from this view). When it is printing those solid layers and they cool they shrink and pull very hard and warp the sides of the frisbee up off the tape.

    You can fix this by putting down fresh blue tape and cleaning well with isopropyl alcohol. This makes the blue tape AMAZINGLY sticky.

    Also it's helpful to set the skirt distance to zero and add 4 or more loops ("line count") of that. This makes it harder for air to get under the part and continue lifting it off the bed. I have no idea how skirt and support will interact and it might not work properly. So after slicing make sure the skirt is touching all around the frisbee and that it and the support structure don't interfere with each other.

     

  8. If you had assembled it yourself you wouldn't have any confusion. This is the part of the instructions that describes in detail how to level and adjust the height of your bed home position:

    http://wiki.ultimaker.com/Ultimaker_rev.3_assembly:_Mounting_the_electronics#Step_10:_Checking_and_aligning_the_Z-homing_switch

    Please save a link to these instructions as you will at some point need to take apart and understand every single wire and bolt in your ultimaker. You are pretty much guaranteed to have other issues. In fact you should check for loose bolts right now. It sounds like your Z limit switch came loose.

     

  9. I haven't needed to adjust the z limit switch since my first day of printing. I always just adjust the 4 screws.

    I use paper as my spacer. You should be able to slide the paper in and out under the nozzle at all 4 corners but not so loose that you can't tell how big the gap is. You should be able to slide the paper under the nozzle with one hand, kind of pushing it under. If it gets stuck and wrinkles then you probably don't have enough of a gap.

    When you print the very first layer it should be *almost* touching the print bed such that the first layer is squished flattish. Not rounded beads. But if it's ripping the tape your levelling is way off.

     

  10. I am definitely noticing that disconnect between extruder drive movement and physical extrusion. It's definitely making me want to suspend the extruder drive above the machine, cut the bowden tube length in half, and have a much more direct, lower friction, filament path.

     

    Yes, well this is the weakness of the ultimaker. Moving the feeder farther away means the head can move much faster. I've seen photos of other people who did just what you say - suspended the feeder above the ultimaker with string. But I still think you can get good results if you keep experimenting. Maybe your spring should be tightened on your feeder so you can get down to 200C or so? Make sure you print at lower speeds - e.g. 50mm/sec with .2 layer or 100mm/sec with .1 layer when going under 200C.

     

  11. Let me clarify that - I can't print 190C at 200mm/sec. But the speed doesn't affect stringing for me - just the temp. The retraction feature is the key thing and then secondarily, lowering the temp keeps the nozzle from leaking - even a little.

     

  12. One would think. But I can print very slow and still get no stringing easily by lowering my temp to 190C.

    I wish you would post a picture. I assume you are talking about very minor stringing at 225C. I get absolutely zero stringing at 190C with 4.5mm retraction enabled. At 200C sometimes I get stringing, sometimes I don't and it's very minor. I can print at 200mm/sec or 20mm/sec and it makes no difference.

     

  13. I'm glad you are happy.

    For layers that take more than around 20 seconds you shouldn't need the fans. But when you have layers that can print in 2 seconds - for example the antennas on the top of the ultimaker robot - then fans help a lot. With my fans on at 100% I can print 5 second layers no problem. If I print much faster (say 1 second layers) it looks like crap even *with* the fan. I have been meaning to test with the fan on and the fan off. Will test that eventually.

    Sooo - don't throw away your fans just yet. I'm sure you will have plenty of parts in the future where the top most layers print in under 5 seconds.

     

  14. 1) Don't print thicker than .2mm or faster than 100mm/sec for your first print.

    2) Consider raising the temperature to 230 just to figure this out although 200C is normally fine.

    3) Are you getting clear teeth marks in the filament? Your feeder needs to be very strong. Try tightening the feeder and maybe examining this bolt:

    http://wiki.ultimaker.com/Ultimaker_rev.3_assembly:_Material_feed_mechanism#Step_2:_Drive_bolt_assembly

    I had to play with the washers and add my own washers to get this bolt to line up as well as in the picture. I did not follow the directions by the time I was done with it.

    Look at the picture at the bottom of this page. This is *good* teeth marks:

    http://umforum.ultimaker.com/index.php?/topic/291-extruder-calibration/page-3

     

  15. Unless you really are invested in this mentally I wouldn't get it for a class. It took me maybe 20 hours to get all the kinks out. What I thought was perfectly assembled ended up having a slightly loose set screw, a rubbing belt (that looked fine) and didn't know about using isopropyl alcohol for the first 20 prints. It can be very frustrating. 20 extra hours for a teacher might be months or a year unless you take it home and spend 2 hours every night for a week. Other people have occasionally gotten a defective part that wasn't obvious, made a mistake in assembly, miswired motors, and more.

    But it's also very rewarding. If you are willing to bring it home and tinker with it until it works nicely, and if you are the one who kicks off every print manually, then it could be great. If you go for it, be prepared to have to take pictures and post them on this forum, but you *will* eventually get it working if you do that and follow all the advice. It just might take tens of hours.

    I'm thinking in a CAD/architecture class it would be fun to print the kid's house designs (with removable roof or missing roof of course!). However I think the UM really is amazing for artists.

     

  16. Your brim looks too thin - you should relevel using a piece of paper. I think you started printing with the z stage too high by maybe .1mm. This can grind your filament and cause all kinds of trouble.

    However this has nothing to do with what you are complaining about because it printed the base of your part just fine and by the time it got to the trouble section you are fine.

    Rather than rebuild marlin, consider just lowering the retraction speed to 25 as illuminarti suggested. You probably already have the latest Marlin as I believe it came with cura 13.13. Watch the retraction wheel and see if it seems insanely fast and makes bad noises. If so, lower it by another factor of 2X.

    This is a very strange printing problem to me.

     

  17. FYI - it's important that the first layer is *pushed* into the tape slightly. The initial string of PLA coming out should be wider than it is tall. If it looks cylindrical then you need to raise up the bed slightly. You don't want the first layer sitting slightly above the tape.

    Next time just *barely* clean the blue tape with isopropyl so it doesn't stick so well. lol.

    Also you only have to use higher temp and slower printing on the very first layer. The rest doesn't make any difference. PLA sticks to PLA just fine at any temp >=190C and any speed. In fact people who use heated beds often turn the bed *off* after the first layer is done printing.

     

  18. Yes, you only need the hex file.

    You can use Cura or other software. I think I used pronterface but they both do it. Also I think the arduino IDE can possibly do it also.

    It's strange you had to do all this stuff. I didn't have to do any of it. I just followed the build instructions on some website - it was basically just a few button clicks. No editing. Not sure why you had to do so much editing.

    My only editing was Configuration.h.

    I think I might have followed these directions:

    http://reprap.org/wiki/Marlin#Configuring_and_compilation:

     

  19. In theory, tightening or loosening the belts don't eliminate "ringing". It changes the frequency. The resonant frequency is a function of belt tension, and mass of the print head. Other things can dampen the ringing e.g. if the rubber in the belt isn't a perfect spring and has higher resistance at certain frequencies. I would expect the rubber to act less springy at high frequencies but I don't know how high is high frequencies.

    So if you tighten the belt to exactly twice the current tension I would still expect ringing but closer together.

    It seems to me we should be able to add a tiny box of loose sand or similar to the print head to help reduce ringing. The energy from the ringing would shake the sand and warm it up slightly and dampen the ringing.

    You can also reduce the ringing by reducing the acceleration and/or the "jerk". But this slows down prints. Be aware that if you change these values you have to save them or they will get lost when you power cycle marlin. You could add them to your "start gcodes" or you could modify them using the ulticontroller.

    The amount of ringing on your prints is small enough for me that I don't mind it at all.

    If you want perfect prints one thing you can do is sandpaper the lines off and then paint with a thin coat of automobile primer spray paint. This is a common, standard spray paint found at auto parts stores. The problem with only sanding is you get a dull finish where you sanded. Some people reheat the plastic to get it shiny again. Some people use a solvent, but solvents for PLA are rare but you can google about this.

    It's not 100% clear to me if your vertical lines comes from:

    1) ringing (which should fade out left to right - this is most likely but hard to tell in your pictures)

    2) STL - some stl models have vertical lines in them - visible in the cad software.

    3) oscillating plastic due to high temp. Unlikely but details here:

    http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

    Other slicers (not cura - try kisslicer) let you modify the vertical seam so it's on a different random position on each layer. I prefer to have it in the same spot every time so I can rotate my part to have that hidden. Don't use Joris setting to remove vertical seam unless you have a simple solid with no holes or cavities (a cup is really the only thing you can print with Joris) as Joris can wreck a print for anything more complicated than a cup.

     

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