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Discussion in '3D printers' started by Carl Feniak, Sep 29, 2014.

  1. AK Eric

    AK Eric Journeyman
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    Ballpark understood: yah, the 8825's are 32microstep, and they're basically double the values my 16step A4988's. When I swapped them out originally I couldn't figure out why everything was only moving half as far... ;) So if you divide my values by 2, you'll get something rough to start with.
     
  2. Elmo Clarity

    Elmo Clarity Journeyman
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    Gawd. No wonder my extruder was shredding the filament. It was set at 420! That was the default in the sample configuration file. I knew it was way too high. :)
     
  3. Muh_3d

    Muh_3d New
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    #2 for me. :)
     
  4. jk2060

    jk2060 New
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    #2 looking great..
     
  5. grat

    grat New
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    It may be because of the angle, but in this case, I think I prefer the simple plate. The chamfer clashes with the corners of the base, which may be the most ridiculous sentence I've ever typed.

    Now, if you made it a full round edge instead of a chamfer, I might prefer that-- kind of an art-deco look:

    curved.png
     
  6. Raldan

    Raldan New
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    Put me down for #2. The only reason I don't chamfer something is because I've already filleted it. :)
     
  7. ruggb

    ruggb Well-Known
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    I am trying to figure out how one comes up with ur steps/axis.
    mine r 200,200,800,299,9

    for X, Y, & Z ur numbers r 0.13%, 0.27%, % 0.6137% dif from my calculated values based on the part parameters. The extruder value obviously gets more accurate when measured b/c filament isn't as fixed as a gear, belt, or motor.

    My eyesight & calipers can't possibly get to that measurement accuracy.
     
  8. Carl Feniak

    Carl Feniak Journeyman
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    Grat,
    The reason I don't do rounds here is that the backside of the bracket has the V-slot alignment protrusions on them, which means that the brackets must be printed with the outward face down. The issue with this, combined with rounds, is the start of the round is like printing a 80 degree overhang so you aren't going to get a nice surface finish.
    Yeah, I know what you mean about the clashing of rounds versus chamfers, but those are just little 1 mm rounds and will be barely noticeable in the finished part. I could extend them to the base though and it would make things look more continuous (or remove them all together).
     
  9. grat

    grat New
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    Oh, fine, be reasonable, take things like printing quality into account-- see if I care! ;)

    I take it you're doing heavy rework just as I'm starting to print my parts from the old set (well-- I'm actually using the parts from adam's triple C-Bot for the most part)?
     
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  10. Carl Feniak

    Carl Feniak Journeyman
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    Yes and no, a lot of changes for sure but the basic design concept remains the same. Key changes are much "beefier" printed parts, endstop rework, and Z axis change. I made a bunch of progress already but Christmas and other stuff has slowed me down. Hopefully will release for comment in the first week of Jan.
    Other than the 3 lead screw adjustment Adam made, are there other mods that I should be looking to incorporate or take inspiration from? (Will be looking at his XY endstop setup for sure)
     
  11. grat

    grat New
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    For me personally, no-- I'm completely ignoring his leadscrew parts-- instead I'm using the openbuilds tr8 leadscrew/nut block, a NEMA-17 motor bracket and an F608ZZ flanged bearing. See picture below-- easier than describing it. It has the advantage of being considerably less expensive than the Zen toolworks leadscrews ($20 ea. vs $45 ea).

    While gravity will hold it in place, I'm considering a small printed piece to clamp the bearing into the bracket.

    Obligatory picture of my mock-up version:

    IMG_2409.JPG

    Likewise, I haven't decided if I'm going mechanical switch or hall-effect for the end stops, and may either go with a bare A3144 sensor or the small board (HALL-E) from the RADDS guys, so have no idea what sort of endstop mount I need yet.
     
  12. Carl Feniak

    Carl Feniak Journeyman
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  13. TruculentMC

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    Yeah, PEI for the build plate is awesome. No need for hairspray, glue stick, PVA water, ABS juice, or anything. It just works, and a little buffing with a clean cloth keeps it in good shape. I got mine from McMaster, $20 for 12x12x.040" (McMaster-Carr). Stick it down with some 3M 486MP tape, 12x12" sheet is available on Amazon but it's in a 6-pack.

    I think 3-point mounting for the bed would be a good and easy mod.

    Any reason to not move the hot-end mount up? There's an easy 50-100mm (depending on hot end) of Z-axis height to be gained for free.
     
  14. Carl Feniak

    Carl Feniak Journeyman
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    Glad to hear, I ordered some from amazon then came across a couple negative reviews that had me doubting it.
    3 point mount: I understand why it would be easier for leveling, but...
    ---I have had absolutely no issues leveling my 4 point bed and almost never have to re-level it
    ---heated pcbs typically come with a hole in each corner
    ---A four point bed is better for supporting a 12"x12" bed weight wise
    That said, would be very easy to do, even with the existing design.
    Hotend relocation: Not a bad idea and I've thought of it in the original design as well. The main reason I didn't is for airflow through the cooling fins of the hotend, which gets complicated if you go dual extrusion plus want to have a part cooling fan. This wouldn't be an issue if you used the water cooling system someone posted a few pages back, but with an aircooled hotend couldn't I think of an elegant solution. Ideas?
     
  15. Raldan

    Raldan New
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    I've been using a product called Buildtak. Is that similar to PEI? I'm really impressed with it. It's made part adhesion one less thing to worry about. Comes in 12x12 sheets.
     
  16. grat

    grat New
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    If I recall, Buildtak is a variation of Ultem, which is PEI based.

    So they're pretty closely related.

    I want to like buildtak, but I've always had problems with too much adhesion... getting the part loose required something approaching divine intervention.
     
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  17. Carl Feniak

    Carl Feniak Journeyman
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    @Raldan Yeah, I think they are based on the same material based on what others have said, though Buildtak doesn't officially say what the material actually is.
    Grat, with no actual experience on this front, others have said that if your bond strength is too high then you should drop your heated bed temp slightly. The buildtak site does have a special spatula for sale so I think this isn't an uncommon problem.
     
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  18. trublu832

    trublu832 Well-Known
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    Does anyone have a good relatively quiet alternative for the 30mm fan on the E3D v6?
     
  19. adamcooks

    adamcooks Well-Known
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    I think my Z endstop is probably worth examining. adding a small platform to the carriages, and using those mini switches reduces the printed parts down to 1 and makes adjusting a breeze.
     
  20. kbud

    kbud New
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    I have my version of a triple-C bot complete (with some minor issues).. But one larger problem i'm having is extruder trouble.

    I have a fairly long bowden tube, maybe 400-500mm. I'm using the extruder from thingiverse mentioned in the build tab here (Direct Drive Bowden Extruder; MK8 version by cfeniak)

    i have a universal 1.75mm e3d v6
    my mk8 will sometimes strip out the filament.. i hear it skip steps from time to time as well.


    I tried using some ABS (can't remember brand) that ended up gouging the filament enough that the teeth could no longer bite..
    do you think this is a problem with my length of bowden tube? i've printed the direct drive extruder plate from earlier in this thread.. going to try that tonight.
     
  21. trublu832

    trublu832 Well-Known
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    Your setup is similar to mine, I have the E3D V6 with the same bowden mount but I have 800mm of bowden tube and print fine.
    Make sure your hot end is up to temp all the way and make sure your filament is tight in between the mk8 and the extruder bearing.
     
  22. kbud

    kbud New
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    what speeds are you printing at?
    i wonder if i'm going too fast... i have a printrbot simple metal and am printing at what seems to be roughly the same speed
     
  23. trublu832

    trublu832 Well-Known
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    Nothing too fast, less than 100mm/s but you should be able to feed filament fast enough at that speed as long as your hot end is the right temp.
    Can you adjust the tension of the extruder bearing flange like the one shown on the extruder page?
     
  24. kbud

    kbud New
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    i think that's faster than me.. i think i'm printing at 3000mm/min or slower in my slicer (simplify3d) (side note: it's annoying that the 3d printing community hasn't standardized on speed units yet)

    i'm using a smoothieboard.. i haven't really looked at the speed limits in firmware, so i'm not sure what actual speed it's printing at.

    i used to use a sprint/bolt/nut like the one shown on the extruder page.. after compressing the spring to the max i ditched the spring and just tightened the bolt directly. I got it so tight that the extruder motor would skip and then loosened it until it stopped skipping


    I have this problem on hatchbox pla at 205.. it's worse with abs (forgot brand) at 230-240
     
  25. adamcooks

    adamcooks Well-Known
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    I would think that if you had to ditch the spring and deviate from the design so much you may want to look at the part.

    I see two potential places for error
    -designed to be drilled out for 1.75 or 3mm filament
    -designed to be drilled out for a 5mm or 1/8 coupling
    Is is possible your holes are not concentric?

    If you can still print, try B'Struder: Universal Bowden 1.75mm Extruder by tempo502 , I like the lever for filament path feature.
     
  26. grat

    grat New
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    I've got a 600mm bowden (on a delta)-- shouldn't be an issue. I'd check the feed rate / accel values for the extruder.

    I'll second the vote for the B'struder, but it's not going to solve your problem-- It's just easier to load/unload filament (I prefer "squeeze-to-load" extruder designs).
     
  27. adamcooks

    adamcooks Well-Known
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    I'm still hung up on the "had to take the spring out".
     
  28. trublu832

    trublu832 Well-Known
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    The extruder design you started with should work fine. I haven't had any problems with it and Carl has had it working even longer.
    Are you extruding at all? If you cant get any filament to come out the filament might be stuck on a ledge where the bowden tube meets the heatbreak. Make sure the bowden tube is fully seated into the hot end.
    If you are occasionally digging into the filament and it is not extruding it seems like you are not staying hot enough to keep the filament liquid.
    The extruder bearing just needs to be reasonably tight against the filament.
    Can you verify proper hot end temperature with a temperature graph over time?
     
  29. Carl Feniak

    Carl Feniak Journeyman
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    That is a good question. Not sure.
     
  30. Carl Feniak

    Carl Feniak Journeyman
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    Yeah, either the spring was far too weak or too much pressure was being applied. This makes large teeth ridges on the filament that can catch on the ptfe to thermal break transition and increase friction. Worsening the problem or causing it in the first place.
     

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