As promised I've started a separate thread on this. I had mentioned over at my Alan thread that I was thinking about using hoverboard motors for a rolling base for the full bodies of Alan and Alena. These motors are super cheap at about $25 a piece on ebay. They are 3 phase just like the 3 phase hobby motors for cars and planes. So there should be driver support for them.....well yes and kinda no.
I have been watching a motor controller called the ODrive. Its all open source (hardware and software) and its a dual motor driver. I posted a video of these motors on a grocery cart driving around using hoverboard motors. So I bought an Odrive. I ended up buying a whole hoverboard so I could use the charger, battery and some of the connectors. This one came from Frys and cost $100. Its good upto 265 pounds.
Well now the bad. The ODrive is still a work in progress and not too intuitive. But they have a good write up on how to set them up with the hall effects encoders. All went well until I tried to save out to the board. Over and over again i could not get it to work right. I posted on the forums and got no reply back as to what the issue could be. So after days I began looking for another solution.
I found a great source in china that is making opensource stuff for skate boards. The got 2 single motor drivers. Each one has a standard servo connector and i can use two of them for mixed mode (tank mode). Each board costs $85. So its a bit more than the ODrive ($150 with shipping for the 48 volt ver.)
The name of the board is the FSESC 4.12 50A Based on VESC 4.12 from Flipsky ESC. And can be found here: Flipsky ESC
This controller can be completely programmed with their really great software..automatically figures out all the poles for the phases. Set up the frequency for the pwm and even have shut offs for voltage mins etc. They have a good youtube channel with vids on how to set up everything.
I have the video of the break down of the hoverboard done. As soon as I get these control boards I will be doing tests with the ezb to control them. Then I'll put together a final video and post here.
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Cool....you can follow along with my trials and tribulations!
You can use nearly any type brushless motor with these controllers. Skateboard, hobby style like this 320KV Turnigy Multistar and you can use standard DC motors too. Below is one of those motors in a 3d printed gear housing.
Here is an old video from the author from 2015, where he is playing with the implementation of position control and a skate board motor. Here he uses a encoder to turn the motor 1:1. Jump forward to 8:00 to see him move the motor.I have an old 3D printer stepper which i assume could become a reasonable servo. I have a pot which i could use for the feedback, or will it need to use a digital encoder like the one on a blown display i have.
Not sure on that. I'll have to do some digging.
Hi Will, i checked out the tool setup. Very straight forward. When we use it in tank mode i assume we isolate the drives so the CAN function is not used. I also assume we set the drives up the same as we would continuous servos. This should end up a big Roll or Adventure Bot. Right? Slippage then is not a concern. We end up hoping the nav system will trim as we go. I had planned originally to use an Adventure Bot to test the Nav system. What are your thoughts?
A quick update on the base design. It may end up a 5 wheel design. What's your thoughts?
I think I'm going to set this up with the continuous servo in the ARC. Then I can control it with the iphone and the mobile interface. The default for the continuous servo acts a mixed mode (Tank mode). If you use the left and right controls the wheels rotate opposite directions. I will have to test when I get everything.
5 wheels might work to stabilize your platform.
LOL...... It sounds like you really are going to strap in your son and drive it down the street.
....he's informed me we might have to use a crash test dummy first.... his oversized teddy bear, Brownie.