Building An EV/Hybrid: A Hands-On Classroom Project

I’m a retired Special Education teacher. Many teachers feel that our special kids really can’t do very much.  Frankly, for the most part the kids agree.  I happen to think anyone can learn, especially by engaging the hands as well as the mind. The original goal was to build a functional hybrid vehicle capable of over 100mpg. In our dreams, it would have ended up something like this. Like many of life’s ambitious goals, we didn’t exactly get all the way there, but the journey itself was the real learning experience. And learn we did.

There were a couple seeds planted very early on for this project. The first was when as a small business owner I found myself unable to hire high school graduates who had much “work sense”. The kids in our country are taught subject matter to help them pass a standardized test. Money for vocational programs has shrunk to meet other mandated goals.   It is my belief the focus is on memorization versus reasoning. Obviously, both must really happen.

The second was when I read an article in Mother Earth Magazine. An engineer named Dave Arthur had made a hybrid vehicle for peanuts.  That article is still available online.

Dave Arthurs amazing 75mpg car article from Mother Earth Magazine

I used this project as a  springboard for a plan.  (God forbid a seminal thought.) My project came about years after the article. I was teaching and my students had become very bored with the traditional curriculum.  Discipline had become a real problem.  Many kids would rather be thought of as bad than stupid. Can’t or won’t do the work? Disrupt the class, go to “In School Suspension”.  Avoid the work.

Not everyone is headed to college but that seems to be the assumption.  Obviously students have to learn to read and write. After all, they need to write to sign a paycheck.  But they need to work to earn one.

I wanted to develop an idea that could put my students to work and actually interest them at the same time.  The focus needed to be on science and technology which we taught about four hours per day. I decided we would attempt to create something similar to the Mother Earth project.  My Administrator thought I was crazy.  Perhaps I was. But some of my kids had a practical intelligence that was surprising.

My administrator gave grudging permission after being assured that it would not be an expense to the school and that I could tie the project in with the Science and Technology classes. Permission was about all I got. No shop and no funds. That was just fine.

Some things had to come together.  I needed an electric motor that I could afford.  I found one at Burdens Surplus Salvage.  It was rated at 10-hp as a motor and it was WW2 surplus.  It was manufactured to be a generator for an airplane of that era.  My birthday was prior to the coming school year.  I convinced Mama to buy the motor. She didn’t mind if I threw my gift money away.  It wasn’t designated for groceries or mortgage

A "starving teacher" with his birthday present

A motor/generator has a shunt winding.  In plain English that means that it is designed to work at a constant speed and that a golf kart type speed controller is not effective.  Series wound motors are generally used for propulsion. You may remember from the submarine article, some motors have a series/shunt combination winding.  A shunt winding means that a motor will not have 100% of it’s torque at zero rpm.   You can use a rheostat in series with the shunt winding for speed control.  It also means that there is a need for a clutch.

I found an adapter that was pretty cheap from an outfit named Wilderness EV.  Theirs fit between a VW clutch and the motor. That allows the motor to spool up before being engaged. You can do the same thing with electric or centrifugal clutches like those found on automotive AC compressors or go-karts. The only problem was that I didn’t have a VW to put it in. I thought, however, that it would make a good solution.

While totally minding my own business I ran across a derelict VW at a used car lot a short distance from my school. I went inside and spoke to the owner. He was a former Marine that loved kids. Once a Marine, always a Marine. I had been a Navy Corpsman. The two corps have shared so many wars that one has to be really obnoxious to not get along well. Any grunts or FMFers out there? Semper Fi.  For that reason more than my wonderful personality, he gave us the car.

I loved the price and towed it home. Mama was delighted to see that I had managed to further lower the property value by parking a dumpster in the yard. I had thought that would happen and it hastened the availability of funds to get the project moving. I started stripping the derelict a lot at home. I think I might still be stripping if not for the welding class.

One man's junk is another man's treasure

A “gas axe” strips pretty  rapidly. They then welded the head from a Suzuki 1100E (1978) that I just happened to have, to the frame.

Trike in a truck

Now some of you may be gazing in awe and wondering who designed  the tube frame under this thing. I confess, it was me. Or else it was a gate that I bought at tractor supply and pressed into service. You choose your version of reality. The automotive shop pulled the engine and using the adapter kit from Wilderness EV connected the electric motor to the transmission. That meant that it was time to go to work again for my kids and I.  You can see that the faces are blurred.  That is for the protection of certain guilty “teen engineers”.

Obviously this also partially answered the problem of not having a shop. Jerk the project home at night.

You just cannot go much anywhere safely without a seat. I just happened to have a fine swing on my porch. Mama didn’t care and was probably wondering how she managed to get stuck with this loser. She just smiled and asked me questions about my life insurance policy.

Trike in a Trailer

As you can see, the head of the trike is mounted in a trailer here.  That’s because life was becoming extremely complicated and confusing. Between teaching full time, doing air conditioning part time, and this project, I needed a cube van to carry all my tools and parts. Therefore, I did this so I could go home and park the trike-in-a-trailer, take my truck and go on.

Kids learning about rust

Floorboards. Ya gotta have em. Metal rusts badly when left outside. Wood rots in this climate. We cut the wood and fiberglassed the bottom. Then we installed the floorboard  and glassed the top.

Next I did some damage to my Sam’s card by buying two marine batteries and the heaviest battery jumper cables I could find.

The motor was rated at 28-29 volts.  I found a generator with the same voltage rating but less power. It was the size that the Mother Earth article had used with a 5hp lawn mower engine for onboard charging. If I stayed at 28 volts my range was limited by how much gas I bought for the 5hp charging engine. The motor was actually capable of running on 48 volts if I managed the heat. Epoxy and bolts to the motor chassis for heat sinks would accomplish that. Likewise a ducted 12v squirrel cage would keep the air moving.

Motor generator for onboard charging

For immediate use I avoided the expensive relays and made a connector from the charging clamps and beaten copper tubing. It didn’t arc much and because I had a clutch I did not need to turn it off and on nearly so often. Also running around a parking lot is far easier on a vehicle than traffic.

Dual disc brakes from 1100 suzuki

The double discs on the front of the Suzuki worked more than adequately for brakes.  For rear brakes I intended to install a diode in a second circuit and planned to use the electric motor for brakes. All the pro’s call this a regenerative breaking system. You could easily use the clutch and shift levers from the seat. We built a handlebar that really was more of a tiller like the early cars used. Standard plumbing galvanized pipe is almost the same size as a Japanese handlebar.

The young lady who managed the class while I managed the project. An essential factor in the project.

When we were hooking up the wiring we provided the entertainment for the school television crew. When we connected the motor to the  battery, the wires became hot and it didn’t budge. It had been sitting forever. We tried again and gave it a bump start. It started and ran perfectly from then on. With 3-4 weeks left in the school year we had accomplished most of what we were after. I started leaving it home more than taking it in. I gave my granddaughters rides around the “ranchito”.

I figured phase I was finished.  Phase II which consisted of a body, real seats, lights, and charging system as a minimum would wait till next year.  It would probably be done at home as it would tend to be much more technical. I don’t know how many mpg this could have gotten.  The Mother Earth article had the Opel GT getting 75. The VW title weight was 1800 pounds.  The trike couldn’t have been more than half that. The Opel GT is listed in Wikipedia as 1860 lbs.  I think I would be amazed if the trike couldn’t have beaten 100mpg even with the aerodynamics it had.

But it was not to be.  With about 2 weeks remaining I took it in for some minor stuff at the welding shop. When done for the day I went out to drive it home. Now finding neutral was one of our shutdown procedures and we had not forgotten. Someone had put it in second gear in the parking lot. I started home at 55 plus mph. [ED: 55 mph on this? You are a brave soul!] About 3-4 miles into the trip something went bang. The motor was falling off the transmission. The aluminum adapters were trash. Second gear was gone and others gears made strange noises.  Totally avoidable had we been allowed to use one of the available shops.

Now you may have come to the belief that yours truly is not too bright. I cannot argue with that opinion. But I wasn’t so dense that I was going to pay to recreate that trike after this. I was devastated. So were the kids. For many of them it was the first thing they had ever taken part in that was successful. A lot of them had anger management problems even without any good reason. They were really hacked off now.  It was a tough two weeks waiting for school to end.

The project convinced me that I didn’t want to do another year without some sort of special project.  The next year we had an influx of new kids who couldn’t work outside the classroom without fighting.  I started doing projects that I could accomplish inside a classroom (hanging gardens/hovercraft/homemade solar panels etc). That year was magic but it was over.

I now tend to focus on the good memories.  I taught for about 20 years but that project was the most special.