Microcontroller

I have been researching what kind of microcontroller systemt to purchase to control the MDM. I did find some powerful but inexpensive ones such as the leaflabs maple:

leaflabs maple

Which has a 72Mhz 90MIPS processor (complex motor control needs about 12-25 MIPS) that uses an open source version of C that is easy to program in. However I would have to write the code for it basically from scratch, this would be a lot of work so I decided to purchase something with more support for motor control with some pre-written library files. I got a microchip evaluation board for BLDC motor control, I also bought an inexpensive BLDC 3 phase motor with built in hall sensors from ebay. I plan on setting up the board with the small motor and getting all the software working, then bypass the mosfet state in the board and drive the honda MDM directly.

microchip

MDM module wiring

With the Honda insight manuals in hand I went through the wiring to the MDM module this evening. I am 99% sure this is correct but I'll double check it before I apply power.
It looks fairly easy to hook up.

Parts

Parts arrive from ebay

Got my parts in the mail. Two IMA rotors and stators and two inverter/DC-DC converters. Unfortunately one of the stators was damaged. The packaging was ok so the ebay seller must have damaged it. Now I have to wrangle with the seller to obtain another stator piece....

Edit: the seller apologized and has apparently sent out a replacement motor unit, should arrive next week

3 phase control

I've been reading up a lot on 3 phase motor control while waiting for my motors and controllers to arrive; I've found a lot of good information online, these are two of the best links:

instructables arduinio motor control

3 phase motor control made easy

Edit: the control is a lot more complex than I thought and will require more computing power, so my initial assumptions were incorrect. Fortunately there are a number of microcontrollers on the market with enough power and some of them have brushless DC library files for easier programming.

More CAD

I bought a flywheel and clutch at the weekend; I measured it up and made a proper CAD model of it. Here's a couple of shots.
I'm still waiting for my brushless motors and controllers; I've been reading up on 3 phase control.

Designing the parts in CAD

I have been working on some concepts to get everything to fit together. I only have the transmission in my shop so I've been using photographs online to estimate sizes and shapes.
I have a pretty good idea how the system will fit together, one large bearing at the flywheel end and a small one at the opposite end. I might use a roller bearing at the smaller end to counteract the thrust load when the clutch is depressed.

Here's an image from my current concept.

How to figure out how much power for your vehicle

In order to size a motor and batteries in a vehicle it is necessary to figure out how much much power it takes to go the speed and range you need.

I use this online bicycle calculator, it can be used for any kind of vehicle as long as you know the parameters:

http://www.machinehead-software.co.uk/bike/power/bicycle_power_calculator.html

For the VW bug, I looked up the CD (coefficient of drag) which was about 0.485. The frontal area is 1.8 meters squared, the weight is around 1140 kg. The transmission efficiency for a car is usually around 85%.

You can then enter a velocity and it reports back how much power at the motor is required to drive that speed.
For my bug I have a maximum of 27hp, so my top speed will be around 69mph, 19.6kw.
Once you have sized the motor you can figure out how far you can go on what sized battery pack. For example at 69mph if you want to travel 69 miles IE one hours worth of travel you would need 19.6kwh (kilo watt hours) for your battery pack.
My pack will be 144 volts because that is the operating voltage of the Honda IMA motor, so divide 19.6kwh by 144 gives 0.136ka (kilo amp hours) or 136 amp hours. I'll be using lead acid batteries which are nominally around 12 volts, so I'd need 12x 136 amp hour batteries.

In actual fact I would need more than that. Batteries have a much shorter life if you use their full capacity, if you only use for example 25% capacity of a lead acid battery you'll get over 2000 charges from it before it starts to age.
You'll only get a few hundred if you run them down real low.
So for the above example I'd actually need 12x 544 amp hour batteries which would weigh too much for the bug.

I'm shooting for a range of 30 miles (at a discharge of 25%) at a low speed of 35miles an hour average. This is fine for driving to work and back and general runs to the store etc.

Brushless drive motors

Just won a bid on 2x IMA Honda brushless motors and 2x inverter/controllers off Ebay. I plan on making a sandwich of the two motors. It will put out about 27hp.

Stand

Made a simple wooden platform to hold everything in place.

Bug transmission

Just got a 1976 VW bug transmission for my motor and transmission build. Spent an afternoon de-greasing it and put it in my workshop. Next have to make a wooden support for it and purchase some brushless motors and controllers.