A robot arm basically has a rocket equation problem. Each motor closer to the root must support the weight of all the ones above it.
An advantage of cable robots is that the motors don’t have to be on the moving part. In a CDPR you can place all the main motors on the wall, and they can all be the same part with the same torque. You don’t even have to place one in each corner. In theory you could have a cable robot in every room in your house and put all the motors in the basement with the lines passing through PTFE tubes in the walls.
In Stringman, each anchor has a pair of motors, one direct, and one indirect, routed though a ceramic fishing eyelet in another corner. Consolidating the motors into fewer components drives the cost down, but two camera angles still gives a good view of the room.
The spool motors are Damiao direct drive actuators (DM-H6215). And unlike an arm, they’re all sharing the load, so they can be one of the smaller models, and having no reducer keeps the noise to a minimum.
If you want a cable robot in every room in your house by the way, I’m your guy. https://t.co/NISnwnUxVI