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gr5 last won the day on January 9

gr5 had the most liked content!

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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. I really don't think it's related to the "2 color" thing. Did you see all those red dots in xray view? That's a hint probably. Can you union all the overlapping volumes in meshmixer? For example if you create 2 spheres and overlap them there should be a way to remove the internal walls of the 2 spheres. Some kind of union feature or "make manifold" or something. I don't know meshmixer very well. What happens if you try to slice just one of the two colors. In other words just load the cape/wings and see if that has the gap. Then just load the rest of mothman and see if it has a gap. If it works fine separately but not together then maybe you are right.
  2. Customer support people around the world tell me that architects drive them crazy more than any other profession that uses UM printers (maybe dentists are worse I suppose). Now I can see why! lol! Note that printing just the faces on all these bricks will be a ton of retractions and you could grind the filament up possibly if you don't print enough between retractions. So I recommend you do these settings to limit retractions. 10 retractions on the same spot of filament is safe. 20 is dangerous but should work. 40 is almost certain failure. Set "maximum retraction count" to 10 to be safe (or if you are getting failures where it grinds up the filament and stops extruding) and "minimum extrusion distance window" to 4.5mm (the default retraction distance or close enough if yours is a little different). You might not hit the limit of 10 but better to be safe. The downside is when it occasionally doesn't retract you *might* get a little string. That reminds me: Also I hear architects love white filament which strings the most. 🙂
  3. I'm not sure the absolute minimum width. Whatever you use for line width (I use 0.4mm line width for 0.4mm nozzle but I think default is 0.35) - double that and that's the nominal minimum width. So 0.8mm. But in reality you can go thinner if you check the box "print thin walls". I think there is no lower limit but I recommend you go at least nozzle width (0.4mm). If you print with a 0.25mm nozzle then you could go down to 0.25mm but you would see the color below coming through a bit. Also a 0.25mm nozzle prints 4X slower (2x thinner layers and thinner lines) so a 2 day print is suddenly an 8 day print. Yikes.
  4. gr5

    Tough PLA Adhesive

    Yes! I agree. It is only slightly more flexible. If you take 10cm of regular pla and 10cm of tough pla, one in each hand, you can barely tell the difference. I really notice it though when I am loading filament (I never use the auto loading thing - I always slide filament in by hand on all my printers: UM2, UM3, S5).
  5. gr5

    Filament Feed - feeder issues with UM3s

    The feeders can pull/push with more than 10 pounds or 5kg of force. A little friction of the spools touching is too small to matter. I'm going to split your problem into 3 categories of problems (although there are 20 possibilities): 1) Feeder 2) print core 3) too many retractions #3 is simplest to fix and diagnose. Some layers may have hundreds of retractions. By default Cura lets you do 30 or 40 retractions on the same spot of filament and that can grind it up. 10 retractions on the exact same spot is safe. 20 is pushing it. 40 almost guaranteed to fail. So look at the failing layer in cura and count up retractions to get a feel for this. You can change retraction settings if necessary. It's probably more likely #2 than #1 but #1 is easy to test. You need this thing anyway so print one of these to help with loading, unloading filament and testing things (to physically feel yourself what it feels like when working properly): https://www.youmagine.com/designs/wedgebot-for-ultimaker2 Now feed the filament half way down the bowden and do "move material" on the menu to energize the extruder and then pull down on the filament hard. You should be able to pull at least 10 pounds without the filament slipping. Tension on feeder should be in the center position of the indicator. #2 - try changing cores. Obviously if that fixes the issue then the problem was with the core. 3dsolex cores are nice because you can change the nozzle. A bad core can usually be cleaned with hot and cold pulls (see this feature on the UM3 menu system). You may have a "bad" core. It's kind of a mystery to me what makes a core bad but it's common. I think it's related to the teflon insdert somehow. Even 3dsolex cores can be problem cores (but most are fine). (I sell 3dsolex cores so I'm biased but I do believe they are better). Once you get a tangle in filament it will not go away unless you remove the tangle. The tangle just travels along forever if you don't fix it. If you never lose the end of the filament (hard to do) it will never tangle. It is possible to remove a tangle by passing the entire spool "through the knot". Hard to explain but easy once you figure it out.
  6. It's a bad model. I looked at the model and sliced it and see the same gap. If you look at the model in xray view it has tons of red spots. That's the problem. The model is not "manifold". It is not a single solid model. Did you make this model? Lots of cad software can convert models with overlapping volumes into a single solid volume (or 2 volumes in your case - one for the cape). Or you could try fixing the model in netfab. netfabb free repair service is here (you have to create a free acocunt first): https://service.netfabb.com/login.php Although I don't know if netfab works on formats other than STL. You could split your 3mf into 2 STL files and fix each one separately.
  7. I think it's random. It slices a layer of STL triangles in to random unconnected line segments (because STL files don't say which triangles are connected). Then it tries to connect line segments together into loops. Each loop of line segments is stored in a data structure - basically a linked list. It prints in the order that they are in the structure probably. But it doesn't always print starting at the begining of the data structure. But I think it always prints in the same order. So when it creates these loops it could start off clockwise or counter clockwise. So maybe it's controlled by the STL file and what order the triangles are found in there. The first triangle found in the STL for a given layer starts the loop and then where it finds the first adjoining triangle - that will set the direction. Most likely. You could experiment with a simple STL file - maybe a cylinder. Find the very first triangle in the STL file and it's xyz position. Find the adjoining (horizontally) triangle and swap them to see if it changes the CW versus CCW travel. [edit: note: I was wrong. Correction in next post]
  8. gr5

    Tough PLA Adhesive

    Tough PLA is indeed slightly more flexible. It's most obvious when handling the raw filament. It is subtle though. It seems very similar to PLA mostly. The flexibility is what makes it tough. It is actually weaker than regular PLA. Also I think it probably stretches a little more before breaking (for example clay isn't flexible exactly - it just deforms (permanentlyish) before breaking). This graph shows more stiff to the right on the X axis and stronger vertical on the Y axis. Both axes are logarithmic. You can click and drag to zoom in. http://gr5.org/mat/
  9. You have to model the 2 colors as solids. It looks like 3 colors in the photo. Anyway, for example you could make some bricks one color and some another. Or you could divide the brick in half along a diagonal or any division you want. But when you get the colored volumes figured out you then create 2 STL files one for each file. Each STL file must have solids (not faces, not surfaces). In cura you assign each STL file to a different color then select them, right click, and merge them into one part. You don't want overlaps as it will print twice in the same volume if overlapping (a little overlapping is sometimes okay or possibly desired if you are doing some clever trick). Does that make it more clear?
  10. This is by far the best way to upgrade to dual extrusion (link below). The original plan for the UM2 to do dual extrusion doesn't work very well at all and I don't want to explain why. Your biggest problem with the mark2 is that UM stopped putting a driver chip for the second extruder on most circuit boards so you might want to look on the board to see if that is missing before going very far with the mark 2 option.
  11. Pay particular attention to faces that are gray versus white in sketchup. Read that part first maybe: https://i.materialise.com/blog/3d-printing-with-sketchup/
  12. gr5

    Z travel is going wrong way.

    You need to set up the printer such that Z=0 means the nozzle touches the build plate and Z=10 means the nozzle is 10mm away from the build plate. Period. It's okay for the homing position to be at Z=200 if that's what you need to do but it's NOT okay for Z to ever go negative. Z=10 does NOT specify if something is moving up or down. It specifies the distance between nozzle and bed. So Z=20 may be "higher" or "lower" than Z=10. But Z=20 is definitely "nozzle farther from bed".
  13. For the last year or so I just put the spool on the table behind the printer. Spool holders are over-rated. Those feeders on the um2, um3, s5 can pull 10 to 20 pounds (5 to 10kg) An extra ounce (30 grams) of force to rotate the spool on my table is not an issue.
  14. gr5

    Wich filament to choose ?

    I would go with a nylon. I'd pick the least flexible nylon you can find. Ultimaker brand nylon is good. Look at the "young's modulus" aka "tensile modulus" aka "flexural modulus" (same thing but measured differently). Every filament has a spec sheet so google the brand and the word "modulus" and you can usually find a pdf. I have a graph showing modulus and strength of many materials. Going to the right is stiffer and going up is stronger. All the nylons are flexible enough. PLA and ABS are too stiff and too brittle for a hockey stick. I would start with taulman 910 or ultimaker nylon. Here's my graph - you can click and drag to zoom in: http://gr5.org/mat/ In my graph heading to the right is stiffer (it's a log scale). Heading upwards is stronger (less critical for a hockey stick). A note about printing higher temp materials like nylon. If you get bad layer adhesion you won't know it until it breaks and it will break along layer lines. Nylon should NEVER BREAK ALONG LAYER LINES. If it does then you printed it wrong. You need to lower the fan a lot. And you need to completely enclose (or mostly enclose a few hand sized holes are fine) the printer to get the air up to 35 to 40C. And lower the fan to 1/3 to 1/10th normal speed. This will help with curling corners but more importantly will help each new layer adhere (melt to) the layer below.

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