Ben Nelson's Electro-Metro Build thread

[Christ]

LOL I love how each of your posts contains some drama.

"Rivers and small animals" - made me giggle a bit.

If you're thinking about using strawbales for walls, remember that you can't just stack them - they have to be braced/fastened together somehow. Re-bar comes to mind.

On another thought, you may be able to reclaim most of the materials you need from wrecked houses and barns in your area (ok, not in your area, but within a couple hours' drive). It's pretty common to build new with old. Plus, if you're set of building something anew, it will give you a fighting chance to work out all those little issues that will eventually happen over time if you don't prepare for them.

Do you live in Suburbia, a community, or a large(ish) plot of land? Maybe moving your garage to another location on the property will benefit you a bit?

Also - Instead of a concrete floor, perhaps a reclaimed brick floor will suit you better? It will be able to move to cope with the earth under it moving, and the sand under the bricks acts as a major insulator, since sand never really packs together. It also helps to keep water at bay, due to it's amazing absorbency, which, coincidentally, is also the reason it insulates... (sand is so absorbent because of the air pocket between each grain and the ones around it, and the fact that no two grains can be aligned so that they occupy less space than the total area of the two grains, thus leaving an air pocket between them, regardless of their orientation)

[bennelson]

Since Paul's motor controller project has me all excited about the possibility to upgrading to a higher system voltage for not too much more money, it's time to investigate what other things I need to do to go up to either 120 or 144 volts.

In my area, there is an "electrical rebuilder" who has been running his shop a long time. In fact, one of my brothers worked there for a few years way back when, and this guy is the uncle of a friend of mine.

The shop rebuilds automotive starters, various motors, and actually does a lot of work on higher voltage bus motors, including electric and hybrid busses - who knew!

I called over there, but he was busy, and I left a message. I was surprised to get a phone call back last evening.

I explained what I was doing, having built an electric car last summer, running it with a forklift motor at double its designed voltage, and wanting to take that even further.

Interestingly, the first thing he asked was how much money I had put into the motor. "Not much". I only spent $50 for the motor and another $50 for a brand new set of brushes.

His premise was this - If I had spent lots of money on a fancy EV motor - DON'T screw with it!

If I have only little money in the motor, go ahead and experiment. He told me that the forklift motors are beefy and can take more than you think they can. By severely over-volting the motor, I am getting into the realm of "experimental" and am designing what he called a "rat-motor", which has the potential of being very powerful.

He said the main concerns are that I would suddenly have the urge to go fast, peel away from stops, and drive fast and hard for long distances. As long as I could resist those urges, the motor should be fine.

A while back, when I got a message from Jim Husted about forklift motors, he said that mine should handle 120v no problem.

The local rebuilder said that I should just shoot straight for 144V.

I did notice on the EVDL mention of drilling a small hole into the back of one of the brushes to insert a temperature probe. Brushes are the first thing to heat up when you are trying to burn out your motor.

I have NEVER had any issues with heat in my car. NONE. The Curtis controller (without a heat sink on it even) has only ever been slightly warm to the touch after a long ride. The motor has NEVER been even slightly warm. I was told that most of the noise from my motor is from the big aluminum fan blade on the drive end of it. When we built the new motor end mount, I made sure to cut the center hole extra big to allow for air circulation through the end vents.

I believe I have an excellent motor to "rat-up"

[begin evil laughter...]


PS - The electrical rebuilder is also converting a Prius to plug-in, from scratch, using a 20KWh lithium pack. That thing should do 60 miles without gas! I will try to find out more on that project as it progresses!

[Christ]

In a way, I wish I had taken more time to sit down and play with the electric generators and starters and motors that my Uncle used to repair for the shop not far from my father's house... The guy that runs that shop builds "experimental" motors for his own giggles.. he's been working on electric motors for like 40 years. (He's about 54 now). Maybe one day I'll go back and see him, if we ever move back up that way... it would be fun to do on weekends, since my Uncle doesn't work for him anymore.

[MetroMPG]

Originally Posted by bennelson

I have NEVER had any issues with heat in my car. NONE. The Curtis controller (without a heat sink on it even) has only ever been slightly warm to the touch after a long ride. The motor has NEVER been even slightly warm.

Sounds like a good candidate. Jim also told me our pump motor would be OK to overvolt. Believe he mentioned 120 also.

I have made mine warm before, doing a "straight shot" discharge - nonstop 20+ km drive. The body got warm, but not hot.

Have you ever touched the bearing area on the commutator end of your motor though? The bearing will get warm (hot) before anything else even starts to warm up. Even when the ForkenSwift motor body is still cool to the touch, the bearing area can be hot.

[bennelson]

When I replaced the brushes, I ran the motor overnight on my garage floor, running straight off a 12V battery.

I was told that it's good to "break-in" brushes by just letting them run a long time on a slow speed.

When running the motor that long, I did notice that the bearing end was warm to the touch. So I take back my words in the motor NEVER being warm. That end of it, running that long was warm. But that's the only time.

I will check on the bearing end next time I go on a long run.

Does anyone have recommendations for a simple/cheap remotely-read temperature sensor?

I would like several, one for the motor, one for a motor brush, one for the front batteries, and one for the rear batteries. Simple and cheap get bonus points!


[EDIT]
Hmm. These don't look too bad. $10 each.

[bennelson]

Happy Anniversary,

If you look at the date of the original post in this thread, it was Jan 28th, 2008 - exactly one year ago.

So what have I done in that year? Did I meet my original goals and dreams?

Let's look back to my first post to find out.

Originally Posted by bennelson

The premise is this.
I am going to build an electric vehicle based on converting a street-legal four-wheeled automobile to run on a DC electric motor and battery pack. I need to do this as an ecological/economic project

Yep! It's %100 street legal, as of a couple of days ago when I put the sticker on the plate. As the car gets the equivelant of 130 MPG, runs on renewable electricity, costs about 2 cents per mile to run, and cost under $1300 to build, tt has been both a econogical and economic winner.

Originally Posted by bennelson

The plan is to buy parts as I can, with cash, and only when I can find good deals. Recycled/Reused is highly encouraged.

Almost everything on the car was used, salvaged, donated, or recycled. About the only thing I would do different on another project would be to try to tackle the machining myself. I paid cash for everything with the exception of a debit card for a couple of mail-order items. Cars depreciate in value. Don't take out loans to buy them, and don't take out loans to build them.

Originally Posted by bennelson

The motor will come from a forklift and be over-volted as much as I can for a resonable, but not high top speed. The vehicle will be used for local travel, errands, and short commutes.

This part really worked out how I thought it would. I did indeed use a forklift motor, although not from that entire forklift I bought. I did use a few other parts from that though. The original 36/48v motor is currently overvolted to 72V, and would like to experiment running it up to 120 or 144 volts.

This is the perfect vehicle for short commutes, grocery shopping, going to the library, and getting take out food.

Originally Posted by bennelson

When finished, it will be something that neither I, nor my wife would be (terribly) embarassed to drive.

One of my brothers pointed out that this is actually the nicest-looking car I have ever owned. Once I took off the pink pin-stiping, whacked out a couple of dents, and painted the wheels, I think it looks pretty nice. No, I take that back, I am PROUD of my work.

Originally Posted by bennelson

I will start off using free/existing controller, batteries, and other parts. When I know what I am doing, I will upgrade to either a purchased, or specially home-made controller. I plan to really look around to see what is possible for batteries. I will check with power utitites, firealarm companies, etc, to see if I can get used/surplus batts.

I never ended up testing the car with my motorcycle controller or using something off the forklift. It did run for a while with my motorcycle throttle, and then with a forklift throttle for a better part of the summer. I really hadn't looked much farther into home-built controllers until the renewed interest because of Paul's Open Source Controller Project.

I was able to snatch up a batch of used batteries at a mere $12 each. They aren't perfect, but they work well enough to get me around, and the price was right.

Originally Posted by bennelson

Planned vehicle will be a two seater. Most the time it will be driven by only me, but occasionally will have a passenger. I never plan on using it for four people.

The car ended up being a 2-door, four-seater. Mostly, it's just me driving. But sometimes my wife rides with, to get dropped off at car-pool, go out to dinner, or drive to the farmer's market.

If I upgrade the system voltage, I won't have the gross vehicle weight available to carry four people, but I will keep the back seat in there for looks and storage space, with the additional batteries hidden in a box under it.

Originally Posted by bennelson

I am thinking that either a compact car because of its light weight and small cost, or a light pickup truck for ease of work and repair, and battery-carrying strength.

Well, it did end up being a compact car. No power steering, no power windows or door locks. Everything very simple and straight-forward. The worst I had to do was add a vacuum pump for the brakes, although I can stop the car just by pushing that much harder even without the vac assist.

Originally Posted by bennelson

I am only in the really early stages on this. I am currently working on buying the forklift which will supply the motor and other parts.

In hind-sight, I totally did NOT need to buy that forklift, but I was very excited about the project, and it included a big charger. I did end up using the ammeter shunt and some other parts from the charger. I used the contactor and some other bits from the forklift. The motors from it are just waiting to be used in an electric motorcycle or lawnmower.

Originally Posted by bennelson

Next will be to decide what vehicle will work best, and then start looking around to find the deal on it.

I was pretty fanatic about looking at cars. It was exactly one month after the "official start" that I found the Craigslist ad for the car that would become the Electro-Metro.

One of the other vehicles on my "short-list" was a Dodge Neon, the same car another local guy is converting to electric.


Since one year ago, I have:

Built an electric car
Broke that electric car
Fixed the thing I broke
Seen actual EV charging stations in the wild
Had my EV video (on the motorcycle) shown at the Plug-In Conference in Washington, DC.
Talked to a Tesla Sales-Person
Talked my way into sitting in the Tesla
Met the Ecomodder guys, helping with their booth at Hybridfest
Showed my EV cycle at the MREA, including meeting Ryland and riding in his CommutaCar.
Used a plasma-cutter
Had a beer with VW hillbillies
Installed a block heater (S-10)
Been on the front page of Instructables
Been dragged around by court Judges
Straight to the front page of 2 newspapers
Got my wife to start car-pooling
Started a bio-diesel project

and too many more things to count. But most of all, I have met a lot of new people, made new friends, and tried a lot of things I have never done before.

Happy new year everyone.

[ham4fun]

While reading your entire blog over a weeks period, I saw someone mention the Espar heater and how it heated air, but if you look at Espar - Coolant Heaters you will find that they have one to heat water. So, heat water for your heater core, and also heat your batteries during the winter. Use the Diesel one and run it on WVO to save even more. You could also run some tubing under the seat to warm the backside too.
Ed ... hoping to talk the wife into letting me build one of these.

[bennelson]

We finally had some nice weather again - got up to 46℉ today. Sure beats the -13℉ we had a few weeks back and the teens we have had in general.

That means I could actually get outside and tinker with the car.

I shuffled around some of the wiring that was still on the floor on the passenger side and dug through my Curtis Controller manual.

On the side of the controller are three screws. You pull them out with a Allen Wrench, and then there are tiny potentiometer screws hidden inside.

The three are for plug braking, throttle response time, and amperage.

I always figured amperage was turned all the way up, but NOPE, there was a little more in there!

I turned the amperage all the way up, and the throttle response speed all the way down.

Then I went for a ride down the street on the 45 mph main road.

POWER!!! Enough to push me back into the seat, well, at least a little. My 300 amp ammeter just maxes out. (It's a 400 amp controller)

Pulling away in second, and then shifting to 3rd, I was able to get up to 40 mph pretty quick. With the throttle speed turned all the way down, it takes almost 3 seconds between slamming on the gas pedal, and feeling it's full power.

You know what that means. Pulling back into my driveway, I parked the car and turned the throttle ramping all the way UP, while leaving the amperage setting maxed out as well.

The gas pedal is now pretty touchy. Just tapping the gas pedal instantly makes the motor spin. Not good for a smooth pulling away from a stop. (Especially since the stop right at the end of the driveway is a little uphill)

However, it IS really good for acceleration!!!!

Since I am now blinded by the shear power of the FULL fury of my 72 volt system, you know what I have to do...... Find the new top speed.

I head north on the main road, over the hill and into the 55 mph zone.
The speedometer reaches 47 MPH. Not really much faster than I have gone before, but SOOO much easier to get there.

Out on the main road, NOBODY passed me. I pulled a U-turn on a side road and headed back home. Of course just before getting back, going 40 mph (uphill) in the 45 zone, I STILL have an F-350 grill in the rearview. I wish those guys knew what they looked like to the driver in front of them.

I threw a volt meter on the batteries when I got back. Dang they were low! High amps really sucks them dry fast!!!!!

The controller was dead cold, as was the motor (including the bearing end)
I did feel all the power cables. They are a mix of sizes, ranging from 1 gauge to 1 ought. The 1 gauge at the rear batteries was very slightly warm when I wrapped my hand around it.

This entire project is sort of "tinker and test" the whole way.
Running a 144V system would cut the amps in half for the same power/speed.

In case you were wondering, I was at 250 amps in 4th gear on a 72V system to go 47 mph. My batteries would be much happier at 100 amps though!!!

[bennelson]

I tinkered a little more with the car.

I cleaned up all the wiring that was on the floor of the passenger side.
One thing that was there was a 12v relay that takes power from the ignition (when I turn the key to ON) and connects 36 volts to the coil of the main contactor. That got moved to the back, right next to the contactor, and screwed down beside it. What do ya know, there are still wood components to the car.



I also removed the 72V pack voltage wire that ran through the car up to the controller power. I ran it through a different hole in the firewall (on the driver side) and tucked it away under the body panel. It still has a spade connection on it which I can manually disconnect for working on the controller.

I've had the horn out ever since I put in the heavy-duty radiator-position battery tray. I went and dug up the old (rusty) horn and re-installed it. It doesn't quite fit right with the battery there, so I had to bend it up on an angle.



Here you can see the adjustment screws on the controller

You pull these screws out and then adjust the potentiometer under it, then put the screw back in. After a couple of test runs up and down the street, I have decided to max out both current and throttle response. It makes the gas pedal a bit touchy, but it also gives me much improved acceleration.

I also FINALLY mounted the controller decent.

I had a short chunk of aluminum (one more nice spare part from Tom!) which reached nicely from the front battery tray tie-down rod, to the side of the car, where there is a tapped hole.

I drilled holes in both ends of the aluminum. The drivers-side end goes right over the threaded rod, and the passenger side goes over an L-bracket held into the side of the car with a bolt going into the existing threaded hole.



What's nice about this chunk of aluminum is that it has slots in it. I ran two short machine screws through the controller mounting holes into matching nuts slid into the track. Since the nuts are the exact same size as the track slot, they can slide, but not rotate. I just used a screwdriver to tighten the machine bolts down, once I had the controller in the position I wanted it.
Although the controller has never even been so much as warm, the aluminum the controller is mounted on should also work as a basic heat sink.




I also flipped the vacuum canister right-side up, blasted the ice out of it with a heat gun, and got the switch working again. The vacuum switch to run the pump was a great idea, but cold/water/ice are in issue in the winter. It freezes up and then gets stuck in an on or off position. It's more inconvenient than anything. If it's stuck off - no power brakes. If it's stuck on - the pump just keeps running (will probably eventually wear on it, and it's noisy)

Here's what it looks like under the hood right now.



I still have plenty more wire clean-up to do. I also want to have the vacuum pump mounted nice and solid, preferably inside an enclosure. Guess the ammeter shunt could go in there as well. Maybe a little box or something for the wound-up trailer wire harness to go in too.

[bennelson]

One thing that has been bothering me is the "pink through the grill".

Straight through the front of the car, you can see the pink extruded polystyrene insulation surrounding the front batteries.

I took the front bumper and cover off and installed a piece of black scrap plastic by drywall screwing it right into the styrofoam.



I reinstalled the bumper and cover over the top of it and got the passenger side inner fender plastic back in place too.

The car now looks black from in front!



This last photo is a super-low angle. You can't see the cables under the car unless you are laying on the road.