IP is in place, so I can share this publicly now.
It is a compound compliant mechanism with inspiration from a Jacob's ladder toy.
Bonus points if anyone can identify the AS mechanism.
https://youtu.be/oRsh7FON_nk
This shows a single cam connection, with very low friction, as the cams are not in contact with each other. The only friction can come from a virtual line down the middle of the crossing bands and is pure rolling resistance.
https://youtu.be/BoRWqZDH7Bw
In the completed horizontal mechanism, even with the compound mechanism, the friction is low enough that I can see my heart beat because there is zero stiction. There are no bearings and in the completed tonearm there are only 2 very strict DOF, all the other DOF are constrained rigidly by the bands. There are no tangency errors at all during rotation.
I tried to measure the starting torque, but it is too low for my crude device, so will try a micrometer to spin the rod on the next build.
6 years in the making, about 30 iterations and 3 working prototypes.
I'm currently building 2 for Brent (90% done) and will have some in action measurements "soon".
Tonearm is 95 mm from pivot to tip, and the fixed cam pillar is 15 mm radius.
Cue will have to be dreamt up later.
It is a compound compliant mechanism with inspiration from a Jacob's ladder toy.
Bonus points if anyone can identify the AS mechanism.
https://youtu.be/oRsh7FON_nk
This shows a single cam connection, with very low friction, as the cams are not in contact with each other. The only friction can come from a virtual line down the middle of the crossing bands and is pure rolling resistance.
https://youtu.be/BoRWqZDH7Bw
In the completed horizontal mechanism, even with the compound mechanism, the friction is low enough that I can see my heart beat because there is zero stiction. There are no bearings and in the completed tonearm there are only 2 very strict DOF, all the other DOF are constrained rigidly by the bands. There are no tangency errors at all during rotation.
I tried to measure the starting torque, but it is too low for my crude device, so will try a micrometer to spin the rod on the next build.
6 years in the making, about 30 iterations and 3 working prototypes.
I'm currently building 2 for Brent (90% done) and will have some in action measurements "soon".
Tonearm is 95 mm from pivot to tip, and the fixed cam pillar is 15 mm radius.
Cue will have to be dreamt up later.