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.
Other robots from Synthiam community
DJ's Fisher Price Chatter
Stonewolf's Here It Is So Far.
You son or Teddy riding it.? LOL
Looks good! We both knew initally it would be too fast but it will be reliable. For the full setup I think it will be a good value. Motors, battery, controllers and charger for about $ 300 I think isn't bad. I am anxious to see the speed test then the dialed down test. The "morph" test video should be about the speed we will probably use and it seemed smooth. The battery life should end up super great.
Definitely not putting a human (or teddie) on it at this speed! Its raining outside, so waiting for a break to go give it a whirl.
Yeah I spent about $300 total, not including the ODrive (which I will use for another project). With other options you have to spend extra on batteries, charger, gear boxes or belts and pulleys to change ratios etc. Seems like the price could get outta control.
I should have no problem reproducing the speed to that of the morph video. As the load increases in weight then the amount of current to get that to move would go up...so figuring out that sweet spot would take some experimentation once you have your robot built and on the platform. Great thing is the UI is so intuitive and easy to use that making adjustments is quick and easy.
Do you think all hoverboard motors are,10 pole? Or do I also have to pull mine apart ? I hope my boards arrive early next week. I will be building a similar base as yours for testing. I will use a rc receiver for the initial tests, unless you advise using a tiny.
By the way: did you ever find out what the extra wire on the eBay motors you have was used for?
Hi Andy, I have used a small magnet run along the perimeter of a similar motor to count magnet poles without taking apart the motor. You can feel the attraction of the magnet pole as as you run the magnet around.
Thanks @ Perry_S. Clever! I didn't think of that.
No not all motors are the same. But sometimes you can find the specs of the motor online. But they are prolly between 28-30 magnets. They are different watts some are 150-350w. So find out as much as you can. As i removed mine (not easy) i lost the silicone seal that makes it water resistant. Prolly ok for a house robot, not for a grass cutter or dog walker
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Perry has a great idea there, except these stators are covered by the rubber wheel..maybe you could come at it from the top with a small magnet?
Well that didn't go as planned, but ended up being fun! After school program was going on......so we ended up with a group of kids!. They loved it and wanted it to chase them! Never really got to test full speed as I did not want to run anyone over. I still struggle to control it with mobile interface on my phone as i think the icons are too small..so next test will be from my 12 inch ipad.
Hoverboard is in pieces. Trying to salvage lights and I think a Blu tooth unit. I think I have the correct voltages to run them. Otherwise I can enjoy watching the magic smoke show. I will be cutting up the zinc base to let me modify and use the wheel mounts. I am too lazy to make new ones yet. Looking forward to getting my vesc, soon I hope.