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Turn extruder 180 degrees ?

Discussion in 'Mods and Upgrades' started by tonycstech, Nov 6, 2014.

  1. tonycstech

    tonycstech Active Member

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    Below image shows probability of turning the extruder part of the entire carriage toward the back.
    Having heavier side of the assembly closer to the pivot (or origin of pulling force) should (in theory) result less of a whiplash effect thus reducing noise and prolong life of bearings at the front of the carriage.

    Its as simple as turning it 180 degrees but as you can see, by doing so i run into the belt.
    This is not 100% acurate image but its very very close to what i will get if i try.

    Has any tried that before ? What were the results and what were the solutions.

    I thought of two solutions that are not gonna work.
    #1 redesign motor mount to bring motor toward the top so it would get away from the belt.
    It will result in center mass shift toward the top and whiplash will take place at the top which is not good either.
    #2 Get the belt further away from the motor.
    Too complicated. Would have to redesign the bottom carriage as well as center of the pulling force will shift, killing the entire purpose of this rotation.

    Do you guys have any thoughts ?
    Problem.jpg
    I can actually think of 1 possible solution that would only require to print 1 gear.
    See below.
    Solution.jpg
    It would need to use smaller gear so firmware changes must take place (plus i dont know how to calculate the teeth ration etc)
    Motor mount would need to have small cutaway at the bottom leaving 2 motor mount points in tact.
    Motor would pivot on the top mount screw toward the gear.
    Another hole would need to be drilled in the motor mount to secure the motor in place with a 2nd screw so it holds on 2 instead of 3
     
  2. ToM Robo

    ToM Robo New Member

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    Tony,

    If the only clearance issue is the motor touching the top of the belt, can you shim the wades extruder up from the X carriage? It will raise the center of mass a negligible amount and possible solve your problem.

    Another possible solution would be to move the X stepper motor pulley further away from the motor, and shim the idler pulley on the other end as well. Not sure if this will work since I can't recall my printer's setup.
     
  3. Mike Kelly

    Mike Kelly Volunteer

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    Have an adjustable bearing that guides the belt and acts as a tensioner. You're sure to have rubbing otherwise.
     
  4. tonycstech

    tonycstech Active Member

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    I don't have any rubbing and the idea to rise everything up may be accaptable, ill have to look into that. Idea was to go as low as possible,that's y its problematic in that corner
     
  5. Mike Kelly

    Mike Kelly Volunteer

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    Well your model doesn't take into account that the belt in wider on the bearing side than the idler sider so raising it up is a good plan
     
  6. tonycstech

    tonycstech Active Member

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    Belt wider? Doesn't make sense.
    Model takes everything into account and its tested and works on stock robot x carriage with little modification if any at all. Only reverse version needs belt pushed back by few mm and there is plenty of room to do so
     
  7. Galaxius

    Galaxius Well-Known Member

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    I think what Mike means is that the diameter of the bearing is larger than the belt drive gear so the top of the belt will sit higher on the bearing end. Maybe that 608 bearing could be replaced with a smaller diameter bearing.
     
  8. tonycstech

    tonycstech Active Member

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    I did just that but after i made sure that stock setup would work.
    That widening actually made very sad that something like that was overlooked.
    Why in the world would you want one diameter on one end and another on another end ?
    Oh well, i guess its cheaper that way.
     
    2 people like this.
  9. tonycstech

    tonycstech Active Member

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    Well it doesnt matter for this model anyway because already tested and working version of this setup that does not care about the belt is already in place and posted on thingiverse.

    So to be clear, images above were just a theory. In practice completely different setup was created that looks nothing like the pictures above.

    I guess this topic should be locked.
     

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