4 ms·

Looks like some great hardware! I love the simple joint design and the variable impedance. I hope sales are successful and this venture is able to perpetuate it

Looks like some great hardware! I love the simple joint design and the variable impedance. I hope sales are successful and this venture is able to perpetuate itself!

Animats 8y ago
Yes. The drone and drone camera industry has made 3-phase brushless DC servomotors with position encoders into consumer products. This robot uses camera gimbal motors. Most previous robots in this size range used either more expensive industrial motors or variations on R/C servos like the Dynamixel. There are many Dynamixel based robots. It's basically an R/C servo with an encoder and a useful communications protocol. It's a fast motor with a lot of gear reduction, not very back-driveable, certainly not enough for force feedback. Typical pricing is in the $1000-$2000 range. The tier below that is robot arms with regular PWM R/C servos. I have a UArm like that on my desk. Repeatability is about 5mm. Costs a few hundred dollars. Not back-driveable at all. Servomotors and motor controllers used to be incredibly expensive for what they do. Over $1000 for a motor controller was not unusual. The actuation end of robotics is getting cheaper, at last.
- fest 8y ago
  Motors from hobby market with custom controllers + belt reduction instead of precision strain wave gearboxes seem to be major cost-reducers. Less precision, but lower cost. More than good enough for perception and control research on how to perform everyday chores.
  - Animats 8y ago
    What makes this work is that the better hobby motors for drones are now pretty good. Hobby motors used to be cheap sheet metal junk.
    - TaylorAlexander 8y ago
      (Brushless) Hobby motors are typically CNC's aluminum and steel these days. Some sheet metal ones exist too. High quality closed loop controllers shipping in volumes helps too. The cheap motor factories can make higher quality motors upon request too so "hobby like" motors can be great in robotics if a big buyer sources them right.
      - Animats 8y ago
        "High quality closed loop controllers shipping in volumes helps too." Yes. Those things used to be way overpriced. I was at an industrial trade show some years ago, and saw that Maxon, a motor manufacturer, had added controllers to their product line. I was chatting with the sales rep, and he said they'd added them because they were tired of selling $100 motors that were used with $1000 controllers, when motor and controller cost about the same to make. Selling both together resulted in a huge improvement in profit margin. Encoders, too. For a long time, shaft encoders, which are very simple devices, were way overpriced. They were separate from motors, which meant you usually needed a motor with a shaft out each end, plus the parts to attach motor and shaft, plus the alignment problems of keeping two things with separate bearings concentric. With the encoder built into the motor, this all gets much simpler and neater.
        TaylorAlexander 8y ago
        Seriously. I dream of hobby motors with built in high resolution encoders in the sub $100 price range. That and a programmable closed loop brushless controller for under $50 would be so impactful.

Looks like some great hardware! I love the simple joint design and the variable impedance. I hope sales are successful and this venture is able to perpetuate itself!

Animats 8y ago

Yes. The drone and drone camera industry has made 3-phase brushless DC servomotors with position encoders into consumer products. This robot uses camera gimbal motors. Most previous robots in this size range used either more expensive industrial motors or variations on R/C servos like the Dynamixel. There are many Dynamixel based robots. It's basically an R/C servo with an encoder and a useful communications protocol. It's a fast motor with a lot of gear reduction, not very back-driveable, certainly not enough for force feedback. Typical pricing is in the $1000-$2000 range. The tier below that is robot arms with regular PWM R/C servos. I have a UArm like that on my desk. Repeatability is about 5mm. Costs a few hundred dollars. Not back-driveable at all. Servomotors and motor controllers used to be incredibly expensive for what they do. Over $1000 for a motor controller was not unusual. The actuation end of robotics is getting cheaper, at last.

fest 8y ago
Motors from hobby market with custom controllers + belt reduction instead of precision strain wave gearboxes seem to be major cost-reducers. Less precision, but lower cost. More than good enough for perception and control research on how to perform everyday chores.
- Animats 8y ago
  What makes this work is that the better hobby motors for drones are now pretty good. Hobby motors used to be cheap sheet metal junk.
  - TaylorAlexander 8y ago
    (Brushless) Hobby motors are typically CNC's aluminum and steel these days. Some sheet metal ones exist too. High quality closed loop controllers shipping in volumes helps too. The cheap motor factories can make higher quality motors upon request too so "hobby like" motors can be great in robotics if a big buyer sources them right.
    - Animats 8y ago
      "High quality closed loop controllers shipping in volumes helps too." Yes. Those things used to be way overpriced. I was at an industrial trade show some years ago, and saw that Maxon, a motor manufacturer, had added controllers to their product line. I was chatting with the sales rep, and he said they'd added them because they were tired of selling $100 motors that were used with $1000 controllers, when motor and controller cost about the same to make. Selling both together resulted in a huge improvement in profit margin. Encoders, too. For a long time, shaft encoders, which are very simple devices, were way overpriced. They were separate from motors, which meant you usually needed a motor with a shaft out each end, plus the parts to attach motor and shaft, plus the alignment problems of keeping two things with separate bearings concentric. With the encoder built into the motor, this all gets much simpler and neater.
      - TaylorAlexander 8y ago
        Seriously. I dream of hobby motors with built in high resolution encoders in the sub $100 price range. That and a programmable closed loop brushless controller for under $50 would be so impactful.