With new python based moteus tview and moteus_tool available, and the new mj5208 motor being included in all the moteus devkits, I figured it was time to update the moteus getting started video. Here it is!
The moteus controller is capable of a lot of instantaneous power. However, to fully make use of that power, you’ll need to keep the mosfets cool on the board. moteus has two mechanisms for that:
- A heatsink can be mounted to the bottom side of the PCB between the board and the motor. This is most useful when integrated into a servo motor, and the servo housing can be used as a heatsink.
- Mounted to the top of the board, attaching to the MOSFETS directly.
In addition to the MOSFETs, the gate driver chip, the DRV8323 can produce large amounts of heat, especially when the controller is run at a higher voltage, like the 44V that the moteus r4.5 supports.
Getting the heat out of all those irregularly spaced components on the top can be tricky, thus mjbots.com now has the moteus heat spreader:
This precision machined and stylish black anodized aluminum piece fits over the top of the PCB and mounts flush against both the MOSFETs and the DRV8323 to ensure optimal heat dissipation from all components. It can be used as-is, or with an additional heat sink fixed to the flat upper surface.
Don’t hesitate to ask any questions in the mjbots discord!
Here’s the approximately annual giant video update:
If you’re interested in any of the topics in more detail, I’ve collected links to individual posts for each of the referenced items below.
Thanks for all your support in the last year!
Announcement of moteus r4.3: Production moteus controllers are here!
Automated programming and test setup: Programming and testing moteus controllers
Continuous rotation: Unlimited rotations for moteus
The virtual wall control mode: New “stay within” control mode for moteus
Handling magnetic saturation: Dealing with stator magnetic saturation
Discussion of the overall design, and details on individual sub-components:
- moteus servo mk2
- moteus servo mk2: Planet Input
- moteus servo mk2: Outer housing
- moteus servo mk2: Front housing
- moteus servo mk2: Back housing
- moteus servo mk2: Functional test
- Making the reduced weight servo mk2
- moteus servo mk2: Reduced weight test
And the pre-production mk2 servos: Pre-production mk2 servos
Ground truth torque testing: Ground truth torque testing for the qdd100
Skyentific’s telepresence clone: qdd100 telepresence demo
kp and kd tuning: Spring and damping constants
quad A1 – Hardware
Lower leg updates:
- The first quad A1 leg: Update leg design for mk2 servo
- The first foam cast foot: quad A0 – Improved foot design
- Longer and with a knee gear reduction: quad A1 leg updates
- A fixture to assemble legs: Quad feet construction fixture
- One of the feet failures: Another foot failure
Cable conduit changes: New leg cable management
quad A1 – Software
Cartesian coordinate control: Cartesian leg PD controller
Pronking: Successful pronking!
tplot2 and its sub-pieces:
- Updated serialization library
- Revised mjlib serialization design
- C++ serialization API
- Log file format
- Video in tplot2
- 3D rendering in tplot
- Video and telemetry synchronization
Simulation: Resurrected quadruped simulator
nrf24l01 transceiver and its sub-components
- Spread spectrum RF control and telemetry
- Spread spectrum protocol design
- Spread spectrum implementation
- Spread spectrum integration
Smooth leg motion: Improved swing trajectory
- Primitive gait balancing – 1D
- Balancing gait in 2D
- Balancing on estimated terrain
- Testing real-life hill operation
Improved stand up sequence: quad A1 stand-up sequence part N
Meet the newest revision of the moteus controller!
Yes, it does look mostly the same as the r4.3 that has been getting a lot of use lately. This revision exists mostly to improve manufacturability, but I snuck in a minor design improvement while at it. Now, the maximum voltage input is rated up to 44V from the 34V of the r4.3! (Note though, that the pi3hat and power_dist still are limited to 34V). Otherwise the new controller is fully electrically, mechanically, and software compatible with the r4.3.
It is now the default in the mjbots store, only $5 more than the old version at $84.