IN DEVELOPMENT BigBox Dual X-Carriages (Bowden)

Discussion in 'Guides, Mods, and Upgrades' started by Greg Holloway, Jan 31, 2017.

  1. Pipshag

    Pipshag Active Member

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    I noticed I didn't put any clips for keeping the Bowden collet stretched up and got some movement in the ptfe tube. Printed some clips and fitted them, will try and see if that improves things!
     
  2. TstarkEngineering

    TstarkEngineering Well-Known Member

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    Im still using the rumba. What drivers belong to what axis?
     
  3. Greg Holloway

    Greg Holloway Administrator
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    Use E2 for the extra X motor, the rest are as marked on the board.
     
  4. W1EBR.Gene

    W1EBR.Gene Well-Known Member

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    @Greg Holloway , if I take a left hand upper x carriage, rotate it 180 degrees and put it on a right hand low x carriage hot end, doesn't this get back almost all of the 25 mm in the x direction that is lost otherwise? I know it means that the fans are opposite each other, but this is what lets the carriages get closer together.
    Or am I missing something?
     
  5. Greg Holloway

    Greg Holloway Administrator
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    I don't see how? Can you explain in a little more detail what you mean please?

    The two carriages are essentially mirrored versions of each other anyway.
     
  6. W1EBR.Gene

    W1EBR.Gene Well-Known Member

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    My description was flawed, let me try again.

    Your design has the print cooling fans on the back side of the x carriages. When the carriages are moved next to each other, the fan brackets touch and keep the carriages from being able to get any closer together.

    My idea is to remove the lower half of the right side x carriage and replace it with a lower left side x carriage that has been rotated 180 degrees. This moves the right side cooling fan to the front of the carriage and keeps the spacing between the two hot end nozzles to a minimum. When these two carriages are moved next to each other, the cooling fan brackets do not touch and the carriages can be moved about an inch closer together until the bodies of the x carriages touch. I think that being able to move the left side carriage about an inch further to the right at x max and moving the right side carriage about an inch further to the left at x min increases the available print area.

    The idea is simple so I suspect I am missing something... :)
     
    #186 W1EBR.Gene, Apr 7, 2017
    Last edited: Apr 7, 2017
    R Design likes this.
  7. Greg Holloway

    Greg Holloway Administrator
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    Ahh ok I see, you mean have the fan on the front of one of the carriages. I've not tried it but I imagine it is possible. I just don't like things blocking my view and restricting access to the nozzle.
     
  8. TstarkEngineering

    TstarkEngineering Well-Known Member

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    @Greg Holloway I am having endstop trouble or something. Do you have any pictures or advice on how your endstops are wired.

    also my x2 doesnt seem to be doing anything at all. When I autohome first time nothing happens, I click autohome again and the following sequence happens: X1 homes to the right, Yaxis homes forward, then the Z axis comes up about 1" and stops.
     
  9. Greg Holloway

    Greg Holloway Administrator
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    Endstops should be.

    Min X
    Min Y
    Min Z
    Max X

    Max X is the endstop for the right X-Carriage.

    Which firmware as you using?
     
  10. Folkert Kaman

    Folkert Kaman Well-Known Member

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    Might want to check whether the endswitch is NC or NO. If this is wrong, it will show the behaviour you described. Just test it holding the endswitch of the X2 in while doing an autohome.
     
  11. W1EBR.Gene

    W1EBR.Gene Well-Known Member

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    @Greg Holloway , I want to alter the carriage fan mount design so that the carriages can get closer together. Could the side chambers on the fan mounts be moved closer to the center? I don't want to change where the air exits. I do want to change the shape of the left and right chambers so that the fans, when mounted on the carriages, are not the limiting factor for how close together the carriages can be.

    I have not tried to do something like this yet, so I would appreciate any suggestions. Thanks!
     
  12. Greg Holloway

    Greg Holloway Administrator
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    The chambers can be altered, that shouldn't be a problem. You might just lessen the airflow slightly.
     
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  13. gonzalo

    gonzalo Well-Known Member

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    Greg, any update on the New Z stepper motors?
    I ordered 2 zesty nimbles and they will be shipping soon. And would be nice to have those in at the same time so I don't have to tear down my box 2wice... :eek:
     
  14. Greg Holloway

    Greg Holloway Administrator
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    They are on a boat inbound I believe.
     
  15. eca

    eca Well-Known Member

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    I take it there are only matched sets and no separate leadscrews? I ordered a set of Ballscrews from Robodig, but they are very big. I would have to drill out part of my bed platform for it to fit, and resize the spacer that surrounds the leadscrew. I was hoping for a drop in replacement but didn't pay attention to the size.
     
  16. Greg Holloway

    Greg Holloway Administrator
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    They are a stepper motor with an integrated leadscrew, the nut has the same PCD and dimensions are the current brass nuts for the separate leadscews that is currently standard on the bigbox. They are a direct drop in replacement, no need to modify anything.

    Just FYI you will need to remove the bottom to get them in though.
     
  17. eca

    eca Well-Known Member

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    Yeah, like I said, I wouldn't need the motor just the screw and brass nut. Unfortunately, I am hoping to not have to order all new motors along with the leadscrews.
     
  18. TstarkEngineering

    TstarkEngineering Well-Known Member

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    @Greg Holloway I seem to have an issue where I go to home and or move the z axis and it will only go in the upward direction(closer to the nozzle). Even after the red light lights up on the sensor it is still able to move upward. So by the time I auto home, then level bed, its crashing into the nozzles
     
  19. TstarkEngineering

    TstarkEngineering Well-Known Member

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    note: that when performing "move axis" it will trigger a "z enstops" code on the lcd but will not prohibit it from still traveling upward and I still can't go down
     
  20. Greg Holloway

    Greg Holloway Administrator
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    Sounds like something is plugged into the endstops incorrectly?
     

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