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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Andy Roid How is your build going? Any movement yet? I'll be back to it on Monday after kids go back to school.
On the road for the weekend. Back Monday. I will begin testing then. I want to scope output of a receiver vs IoTiny to see if signals are different. I don't understand why an rc receiver output works fine and an IO Tiny doesn't? If it was a firmware issues why would you have good results with the rc receiver? I still think it is an input signal related issue. Catch you Monday.
I'm going to swap out the IOTINY for the EZB 4/2 Tomorrow and see if I notice any change. I don't have a arduino to test with.
I'm also reading that there is a safety out of range feature built into VESC, where the motors are not responsive if the the frequency goes out of range.
It’s because you need to enable the use stop position in the continuous rotation movement panel.
Everytime the ezb stops sending a pwm, the receiver has to relearn the signal range.
Your receiver must know the signal range - OR - specify the signal range using the continuous rotation Movement Panel direction values.
Read the ezrobot tutorial on how a servo works to understand how a servo works with pwm. And why stopping pwm for a not smart receiver has that effect.
....everyday is a learning experience. Works perfect! Thanks for this solution AND the explanation. Stops on a dime...!!!!! A tear came to my eye...lol
@Will, Nice project! I got curious ... Q1) Why aren't you using the odrive controller ? Q2) Do you know the wheel encoder resolution ?
My son Liam's first ride on the hoverboard robot at 20% speed, thanks to DJs quick suggestion on the fix for the problem:)
Pedro! Thanks for the kudos. Its a fun project. My problem with the ODrive was that I could not get the config to save on the ODrive. Without the Configs storing, I could not control the motors. So after a long time of messing with it and posting on the forum, I got no reply, I decided to go with the Flipskys and they are fantastic for controlling these motors and VESC is very robust, automatic set up program for 3 phase brush-less motors.
The wheel encoder count is 8192.