IN DEVELOPMENT Moving Y motor to the back outside

Discussion in 'Guides, Mods, and Upgrades' started by Alex9779, Oct 21, 2016.

  1. Alex9779

    Alex9779 Moderator
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    So I played a bit and unfortunately the loop belt we have is too short even if we move the motor axis to the same height as the Y drive axis.
    So if we wanna do this we need a longer belt.

    Given that I thought lets just mirror the current part to mount it from the outside and lets see how long the belt must be, maybe it is a length we can source...
    Here is the result:
    Y Motor Move 1.PNG
    If I didn't do a major miscalculation then the belt should be around 180mm which is one of the lenghts I can easily order on Amazon...

    Also we could just move the plane the motor is mounted to to the same plane as the upper screw case is, then we can move the motor a little upwards too if the belt is not long enough...
     
  2. PsyVision

    PsyVision Moderator
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  3. Alex9779

    Alex9779 Moderator
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    Hmm on ebay I can get additional lengths though 186 might be too long and moving the motor further down is not possible with this design, maybe more to the back but I think I am going for 180 and then adjust the mount to fir that size...
     
  4. Alex9779

    Alex9779 Moderator
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    On German Amazon I have only one seller for closed belt with three lengths 120, 180 and 260, its HexaCube...

    On ebay more different lenghts, I can also order only one belt for 4.45€ and directly from Germany...
     
  5. Ephemeris

    Ephemeris Well-Known Member

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    What's your thought process on the benefit of this? On an enclosed system the reduced environmental temperature can lengthen stepper life, but that's not an issue here.
     
  6. Alex9779

    Alex9779 Moderator
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    It is to increase Y movement limit on the Dual X design...
     
  7. Ephemeris

    Ephemeris Well-Known Member

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    Ah! Allow me to suggest that you add a mounting plate on the inside of the case so the Perspex is clamped (between the plate and the bracket) over a wide area. People will see that bracket as a hard point, even if they know better, and will be tempted to apply significant force to it when moving the BigBox. It won't stop all breakage of the Perspex but it could help.
     
  8. Stian Indal Haugseth

    Stian Indal Haugseth Well-Known Member

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    I have been playing with thoughts like these of my own. I'm also playing with the idea to add a bigger plate on the back with rubber mounts spaced wide to stop to much play. This way we can also reduce the vibrations along the back plate. The adaptor plate should be as heavy as practically possible to lower any resonance frequency as it is not as annoying.

    Please notice I say "practically possible" as a heavy plate would not be so practical ;)
     
  9. AndyVirus

    AndyVirus Well-Known Member

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    Have you ordered those? If so put me down for 2 (always keeps spares), if not I will order those.

    To avoid "cutting" the hole at the back bigger, what about indirectly driving the y axis via another pulley? So motor on the back, with a GT2 16 pulley that connects to a tiny rod mounted inside the big box below the Y axis rod with 2xGT2 pulleys which in turn drives the large Y axis pulley?

    The idea being that you use the existing hole that is there for the motor cable currently. Would need a totally different mount for the motor (or mount it over the hole) and a mount inside for the new rod/pulleys but would not require any more cutting, just drilling.

    Otherwise Ill get the Dremel out, mine is the plywood so simple enough to modify.
     
  10. Alex9779

    Alex9779 Moderator
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    Received two 180mm closed loop belts today, going to print the mirrored mount and see how the dimensions will work before I cut the back plane...

    Off topic: think I am going to print them on my fresh switched to 1.75mmm filament UM2 because I think I wanna go for the 1.8° steppers for X on my IDEX setup before I am trying the next print on the BB...
     
  11. AndyVirus

    AndyVirus Well-Known Member

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    Thinking about this, How much more room on Y will moving the motor outside give us? From what I can tell the max gain will be 6mm. I could be wrong. This of course is perfect as with the IDEX heads we lose about 4mm from the total 200mm available on the bed.

    Considering the GT2 belts are about £10 (granted thats for 10 of them on Amazon) and you have to cut the box to move this outside, would not replacing the Nema17 with a Nema14 not be simpler? This Nema14 is £11: http://uk.stepperonline.com/nema-14-high-torque-stepper-15a-40ncm567ozin-14hs201504s-p-59.html and has 40Ncm of Torque which is close to the current Nema17.

    Nema 17 is 42 x 42mm
    Nema 14 is 35 x 35mm

    So if a thinner Y Motor mount could be made then that "should" give the same amount of improvement on Y as externalising the motor. I am measuring to the Pulley on the Y rod that the motor drives for my max space calculations.

    It was a heavy night last night so please do check that the above makes any sense. :)

    Oh and the only other thing which puts the price up a bit would be a Nema14 Astrosyn or equivelent Damper if there is such a beast.

    OR... Is it possible to shave 4 - 6 mm of the existing motor mount? Looking at my motor there is quite a bit of gap between the motor and rear frame. Obviously would not want it touching but if it was possible to get the gap down to 1 - 2mm then that should give the full 200mm build surface on Y.

    And/Or... on the right extruder for IDEX, move the endstop screw underneath instead of the rear and that would give another 4 - 5 mm. Obviously the end stop switch on the right would need to moved from rear to underside also.
     
    #11 AndyVirus, Nov 6, 2016
    Last edited: Nov 6, 2016
  12. Stian Indal Haugseth

    Stian Indal Haugseth Well-Known Member

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    @Alex9779, you getting anywhere with this?

    I just ordered a bunch of 6mm GT2 closed belts and got 10 of each for $36 :) Let me know if you or anyone else wants a set as I'm not sure when I will be able to start on this. But at least now I got what I need.

    I also measured roughly >180mm and might mount it on a larger bracket with some spacers if too long.
    • 180mm length, 90 teeth
    • 186mm length, 93 teeth
    • 188mm length, 94 teeth
    • 190mm length, 95 teeth
    • 192mm length, 96 teeth
    • 194mm length, 97 teeth
    Anyone wants a set? Giving away 8 sets as long as I actually recieved enough.
     
  13. Alex9779

    Alex9779 Moderator
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    No progress here... I wanna get the IDEX fixed and working... Maybe for the final design I need it maybe not...
     

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