I upgraded two Prusa MK3s to MK3.9, and ended up with a couple of spare boards, stepper motors and a bunch of other things. So I decided to turn them into a Makelangelo clone!

Since the school I work at had these large standing whiteboards, I designed and printed corner brackets to hold the motors, as well as a base for the electronics.

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I’m still having trouble with the homing process, but very happy with the results so far!

I’ll be posting the firmware and 3d printed files online soon.

  • @SchmidtGenetics
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    23 months ago

    You can use multiple pulleys and shackles to take the distance of the rope up.

    It’s how they do it inside of machines as far as I’ve seen.

    • @[email protected]OP
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      23 months ago

      I still feel the distance they travel will stay the same. Except if I use a gear train.

      • @SchmidtGenetics
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        3 months ago

        Using #4 would allow you to move the pen 40cm for every 10cm of counterweight travel.

        • @[email protected]OP
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          3 months ago

          Ah yes, different sized pulleys would work the same as the gear train I had in mind. Thanks for the explanation!

          Edit: on second look, it’s more complex than that, as the weight is not connected to the end of the rope, but on a pulley.

          • @SchmidtGenetics
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            23 months ago

            Likely number 2 would be enough, would double the distance itself. You just need to attach it to the same corner bracket and have a pulley with the weight under it.

              • @SchmidtGenetics
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                13 months ago

                Smaller counterweight may work as well. Can take or add to either side of the equation.

                  • @SchmidtGenetics
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                    13 months ago

                    Yeah I think you need to make it lighter?

                    Using the mechanical advantage for this would be for someone pulling on the rope to be able to lift a weight easier.

                    Your pen is the one pulling and counterweight is the weight, so you would need more counter weight or lighter weights on the pin. But too light would have its own tensions problems….