CAN BUS Control Score 8093
Challenge. Go big or go home.
I'm looking into the CAN actuators used on the Cheetah mini. They are not poorly priced ($300) and offer 150 pound/inch of torque @ 24v. They are brush less, geared and have their own built in drivers, smooth motion and quiet operation. I have an up coming project and would like to control these with EZ Builder. There are arduino shields that support CAN and there is even a pre-written sketch to send data to a CAN actuator. The actuator protocol is somewhat like Dynamixels, in that you can change ID, monitor temperature, control speed, direction and position.
What say you? I'd like to see support added for more industrial actuators like this one, and Servos like ClearPath . Inspiration came from this guy (who cracks me up) and managed to pull this off very quickly using a few of the tools below. Hardware starts at 5:40.
Shield: https://learn.sparkfun.com/tutorials/can-bus-shield-hookup-guide/all Sketch: https://github.com/Seeed-Studio/CAN_BUS_Shield Actuator: Actuator
Just in case someone might find this helpful... There is a link for a tool to calculate servo motor requirements, as for bigger projects it might be good to just kind of eyeball the right components before investing in the actual hardware!
I don't think these controls are needed anymore (CANBUS).
There are many companies coming out with different motors that run on 3 phase like the hoverboard motors. An example is the 9225-90KV Multistar brushless outrunner by Turnigy. James Bruton is using these for another one of his robot dogs. And they are 1/2 the cost (or cheaper) than the Canbus motors and very very powerful, when running at full capacity (48 v). They are also much lighter than hoverboard motors. They have no gearing they are therefore back drivable and compliant. The motors can be used with the same Flipsky FSESC 4.12 50A Based on VESC (Motor control interface: PPM signal (RC servo), analog, UART, I2C, USB or CANbus. ) controllers that I use in my hoverboard hack video.
Mind you these axis would be for large robots. So you bet I have a project with these in mind!
Definitely will see these in an upcoming video.
Mind you you would still have to add an encoder so the motor would not rotate non stop.
Hey, lets keep this thread alive for different ideas on heavy actuators...
I am also currently looking into cheap ways to get a bigger robot arm working!
I was leaning towards a 3d printed cycloidal gearbox, since the reduction ratio vs gearbox size is tempting and it is easy to print, while a harmonic drive is kind of impossible to 3d print!
I was thinking to start with standard Nema 17 stepper motors first and then switch to brushless motors and encoders?
But all of this is new to me, and just a fun thing to try...so lets pool ideas?
I'm really interested in seeing how James will incorporate the hall effects sensor on these motors for tuning position. The motors are designed for drones, so they are meant to be spun up at high speeds, not positional. Looking for torque and holding power on these when connected to the ODrive.
Yeah looking forward to discovering all the emerging new motors.
I will try to find out, how he is getting it done...but yes, those drone motors are nice, because they are pancake style and offer a lot of torque while consuming little space, and it is very easy to put a strong reducer on top!!
But getting those encoders and ODrive, or another system working will be a fun thing to play with!!
Also the Wattage, plus counting the power consumption at startup is essential!
The more I get into this, the more I realize how complicated it is... Which is a good thing!!
Hey, I just ordered an ODrive and some Tarot 4008 motors...
It will take a while for all the stuff to arrive, but it should be a lot of fun to play with!
The ODrive can handle two DC Motors, plus Encoders and Gear Boxes are needed, which adds up to the cost of those relatively cheap motors...
I got the encoders directly from Odrive, and I guess there could be cheaper options available...
Also hopefully I will be able to 3d print my gearbox to save some total cost!
At the moment the cost is about 100$ per joint, which would be 600$ for a 6DOF robotic arm...
This is all WIP and testing stuff, I might open a seperate thread on this, once all the items are shipped!!
Anyone also interested in building a silghtly bigger robot arm?
Could be really cool in tandem with ARCs Exosphere!!
This thread is almost 4 years old and now the robot world is exploding. So to return back to this thread is super important as nearly all the bipedal and dog robots are using some type of FOC motors for their axis. I've been keeping my eye on the development of controllers and the ODrive is continually making improvements to their controllers, encoders, and software for position control in closed loop, including anti-cogging which is a must for position control.
They have two newer products they've introduced including the S1s controller, which is a single motor driver. The software is browser based now and fairly easy to use/set up. Its all opensource as well. https://odriverobotics.com/shop/odrive-s1
The other controller is a micro version of the S1s so you can use it with any brushless motor to turn it into a servo. https://www.crowdsupply.com/odrive-robotics/odrive-micro
If we need to choose a protocol I think its safe to say that ODrive is here to stay and will likely to continue to grow. What say you @DJ? I think it would be a professional addition to ARC and eventually ArcX?!
from website..