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

  1. Carl Feniak

    Carl Feniak Journeyman
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    Okay, no issues with the base then? I cracked my original XY plate once, but it was my fault due to over tightening.
     
  2. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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  3. Carl Feniak

    Carl Feniak Journeyman
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  4. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    Yeah, thingiverse site is misbehaving. Will run it locally.
     
  5. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    Here you go.
     

    Attached Files:

  6. trublu832

    trublu832 Well-Known
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    There's always a risk of overtightening, which is probably what I did also. Seems like a mistake everyone needs to make once or twice to learn from.

    I suppose to make it idiot proof, you could design it so that the belt clamp is flush against the carriage plate when the belt is just snug enough between them instead of leaving a gap.
     
  7. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    Shrunk the nub by 1mm, is that enough room?
     

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  8. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    I've added the YL-99 and Keyes style limit switches along with a generic mini switch to the generator. I don't have any of the YL-99 or Keyes switches yet, have them on the way, but I took a stab at the mounting hole dimensions. If anyone would like to try it out and let me know or measure the hole size and location, I'd appreciate it.
     
  9. Carl Feniak

    Carl Feniak Journeyman
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    Took a look at this file, but didn't get a chance to look at my actual printer. Nub looks a bit too shallow now, but really need to look a the actual setup.
     
  10. ruggb

    ruggb Well-Known
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    I have a 12x12 3 screw setup. I ran into an issue with leveling mine with 4 points. The leveling screws on the ends of the rail with the single screw twisted the rail instead of leveling the bed. Now I have 3 leveling screws, 1 at each lead screw.
     
  11. Carl Feniak

    Carl Feniak Journeyman
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    Sounds like you needed to adjust the locations of the bed mounts to be properly in alignment under the corners of your bed. No?
    The bed should be able rest over the mount holes freely with no torque forces at all other then the small cantilever distance of the mount arm and only in the amount of ~1/4 of the bed's weight. Even after tightening the level springs these additional forces should be internalized between mount, bolt/spring, and heated bed and not transferred to the extrusion itself.
     
    #1451 Carl Feniak, Jan 5, 2016
    Last edited: Jan 5, 2016
  12. Carl Feniak

    Carl Feniak Journeyman
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    Almost ready... but not quite. Just to show some progress:
    It may not look like it, but every part here aside from the V-wheel spacers has been modified (if just superficially).
    Capture.JPG
     
    #1452 Carl Feniak, Jan 9, 2016
    Last edited: Jan 9, 2016
  13. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    Carl, would you mind if I add your direct drive extruder to the generator? Also is there interest in having a coaxial fan mount(s) in the generator?
     
  14. Elmo Clarity

    Elmo Clarity Journeyman
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    No one has had any experience with this? I tried another hotend with the same results. I'm thinking it could be the drive gear (MK8 I believe). I got mine off Amazon I believe. Anyone have a suggestion for someplace to get the gear that has worked for them?
     
  15. Balu

    Balu Well-Known
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    I'm guessing the different colors for the Z axis stepper holders are meant to be variations? :)

    Not being able to decide how I want to build C-bot V1 will now hopefully result in me building V2...
     
  16. grat

    grat New
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    So why the hexagonal holes in the motor mounts?

    If you're going to stick with those, I'd rotate them 90 degrees so the "flats" aren't parallel to the build plate when you're printing.
     
  17. trublu832

    trublu832 Well-Known
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    Can you post your calculations for step calibration?
     
  18. Carl Feniak

    Carl Feniak Journeyman
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    Not at all, please do. I thought you already had a fan mount in there?
     
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  19. Carl Feniak

    Carl Feniak Journeyman
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    Yeah, it will make it easier to point out and discuss the different options... definitely not recommending the use of 6 Z steppers! Will also give mention and link to the 3 lead screw option.
     
  20. Chris Roadfeldt

    Chris Roadfeldt Journeyman
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    I have a blower/squirrel/centrifugal fan mount. Cool, just started the FRC season, so time is limited but should be easy enough to add both in the next week or so. Thanks.
     
  21. Carl Feniak

    Carl Feniak Journeyman
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    I used hexagons instead of a large circle as the top portion of a circle would be like printing a very steep overhang and come out a bit messy and heat effected.
    The given rotation of the hexagon comes out very clean if you can print bridges well. You might have to clean up a stray strand or two.
    With the other rotation there will be some steep but normally quite printable overhangs. The reason I went with the former approach is that when I am trying to print for good layer strength I use a bit extra temp... which reduces my ability to print those steeper overhangs.
    At least that was my logic... what do you folks think? Very easy to switch or provide both.
     
  22. Elmo Clarity

    Elmo Clarity Journeyman
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    I started with a default value and measured the amount of filament extruded vs the amount requested. So the calculation would be (REQ / ACT) * CUR where REQ is the requested amount, ACT is the actual amount, and CUR is the current step value. After doing that a few times, the actual amount of filament extruded is very close to the amount requested.
     
  23. Austin Seagers

    Austin Seagers Well-Known
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    Hi All,

    Just wanted to share a few pictures from the assembly of my solidworks-modelled (triple) c-bot.
    I'm still designing the hotend carriage as i've got a volcano and standard v6 that need mounting. volcano for infill, and standard for everything else.

    The extruder was based heavily on this thingiverse design (Compact Bowden Extruder, direct drive 1.75mm by schlotzz), but changed to accommodate a MK8 extruder gear, and 608 idler bearing as they're what I had lying around.

    [​IMG] [​IMG]
    [​IMG] [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG] [​IMG]
     
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  24. grat

    grat New
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    Ah. My bridging ability on my current printer is... "decent". I get a small amount of sag. One of the reasons for building a new printer is so I can upgrade the old one. ;)
     
  25. Carl Feniak

    Carl Feniak Journeyman
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    Whatever you are printing the green parts on is doing a nice job!
     
  26. Austin Seagers

    Austin Seagers Well-Known
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    Ah, cheers Carl. It's a wanhao i3. Takes quite a bit of wrestling to get to where it can print reliably!
     
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  27. invent3d

    invent3d New
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    It literally took me a couple days, but I made it through (most) of this thread. Tons of great info in here. Great design by Carl Feniak and awesome collaboration between everyone. Pretty refreshing compared to some other forums. But I digress... :)

    I'm looking to make quite a large machine, 1000x750 XY with about 500 Z. The end goal is to print large landscapes and architectural projects, not just a size competition! :p
    I know it's going to be hard, but I'm wondering if anyone thinks I can use some of the concepts here? I'd really prefer the bed to not move *at all*, but I'm not really sure how to make such a large machine with CoreXY concepts. Would the belts simply be too long to scale properly - I'm thinking the belt elasticity might take it's toll or something? Not to mention moving a bed that large is probably insane.

    Anyways, figured I'd ask the CoreXY people here if it's even feasible to scale up that large, I don't mean to hijack at all.
     
  28. trublu832

    trublu832 Well-Known
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    I thought of this printer when you mentioned a non-moving bed
    Maximus 3D Printer | OpenBuilds

    You could look into a concrete printer, the kind they use to print castles!
     
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  29. Austin Seagers

    Austin Seagers Well-Known
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    You might struggle to find a heated bed in a size to suit 1000x750.

    Gt2 belts will also probably be slightly too stretchy for that size aswell. Possibly look into some sort of reinforced belt type with larger than a 6mm width to help alleviate. Although by doing that, you won't be able to use Carl's models, nor easily fit the belt into the extrusion slots.

    Gt2 can definitely be bought in long enough lengths from aliex etc.

    I'd also slice some models you're thinking of printing and take a look at the estimated print time at that size as you might be underestimating it. I can see it easily extending into the days rather than hours.

    What's worth considering is a second infill extruder. I'm going for 300x300x340 build volume and a second 1/1.2 mm infill extruder is going to reduce print time massively on big solid models.

    Are you dead set on printing models this big, whole?
     
  30. Carl Feniak

    Carl Feniak Journeyman
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    Yeah, that is huge. There are some similar designs posted on OpenBuilds that have a non moving bed. A few like this: CoreXY W/ Fixed Build Plate & Enclosure | OpenBuilds
    Deltas are the best for non moving beds, but to get that print are it would have to be massive (not necessarily a show stopper).

    To adapt my design concept to such a size, the trick would be to use 4 stepper motors for the XY. Two driving each section of belt and located at diagonals to each other. This would isolate a section of the belt length between the motors to reduce stretch. Also need the bed moving on 3 lead screws. Could even completely redesign with two belts per section (4 total) and 20x80 V slot (would be a lot of work).

    The CNC approach is definitely doable as well. Only challenge there is that printing something involves +1,000 X the movements compared to CNC cutting a plate and the moving mass of a gantry is very large = slow.

    Sticking with PLA will definitely simplify your build. A surprising amount of commercial printers are on the market advertising only PLA printing capabilities. Also need a volcano hotend and not expect to be using 0.1 mm layer heights!
     
    #1470 Carl Feniak, Jan 13, 2016
    Last edited: Jan 13, 2016

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