Art-a-Tronic Episode 2

RE: Art-a-Tronic Episode 2

mcb1 — Tue, 19 Mar 2019 14:07:10 GMT

Enrico

Depending on the hole in the upper body, you should be able to add a normal bearing that resides on the top of the threaded bolt

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The inner race will sit on this, while the outer supports the body.

It may require a small spacer or 3D printed part to go between the bearing and other parts.

I'd also replace the spherical bottom bolt with a fixed version so that the torso and legs are in the same plane.

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I'd then use a wooden ring attached to the upper body, and a rubber wheel pressing against the inside (or outside) of the ring to make it rotate.

You should be able to mount the motor through the leg.

I you make the motor and wheel sprung loaded, it would allow for any off centre issues and allow the tension to be adjusted.

There are plenty of geared motors, or a geared stepper motor should give enough torque and be much smaller than the one above.

Cheers

Mark

RE: Art-a-Tronic Episode 2

jw0752 — Tue, 19 Mar 2019 12:59:23 GMT

Hi Enrico,

Another great project that is inspiring collaborative participation. I will enjoy seeing how it take shape.

John

RE: Art-a-Tronic Episode 2

shabaz — Tue, 19 Mar 2019 04:46:05 GMT

Hi Enrico,

This is a really exciting project : ) Looking forward to seeing it progress!

Regarding the torso, you've got a lot more experience in motion and motors I think, so this idea I'm about to suggest may have issues to rule it out, but just in case it gives any further ideas: I was wondering if a Lasy Susan type device could be fitted (I think this could be identical to what you're considering with the metal ball bearings if I understand correctly), so that the torso can turn freely, and then use a motor and gearbox, to turn thin steel strip (or it could be plastic strip) - just like a reel of measuring tape basically.. The strip is strong enough so that it would push the lazy susan, but flexible enough so that it can go in a curve. One end of the strip is secured to the motor, and the other end of the strip is secured to the top half of the lazy susan.

The benefit of the strip could be that there is no need for accuracy like with gears. I've never tried this though, so in practice it might not work. I think it may also need some 3D-printed curve around the lazy susan, so that the tape is forced to follow that curved path, when the motor is turning counter-clockwise.

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RE: Art-a-Tronic Episode 2

beacon_dave — Sun, 17 Mar 2019 13:46:50 GMT

A small slewing ring bearing with gear teeth might be worth considering ?

https://en.wikipedia.org/wiki/Slewing_bearing

Insert the motor vertically into that existing hole with a pinion on the end of its shaft to engage with the slew ring gear teeth.