Ben Nelson's Electro-Metro Build thread

[Clev]

I like the idea of the retractable scooter wheel setup, like here: Is it too late? I think not if we act now - MIMA Honda Insight Modified Integrated Motor Assist

If it were good up to about 30 mph, it'd be great for around town, stop and go, drive-thru, etc.

[TomEV]

NetGain had a setup that replaces a section of a rear-wheel driveshaft with a 7.125" motor. Uses a 48v pack and an Alltrax controller. Probably won't accelerate too fast with a 48v system on batteries alone, but might be OK for leisurely driving around a parking lot.

S10 EMIS Project

Looks interesting...

[bennelson]

Yep, there are a few different designs for home-brew hybrids.

I think that the plug-in serial hybrid is the way to go.

Basically, you have an electric car that runs on batteries, and if you need to go farther, you can switch to getting your electricity on the fly from a liquid fuel source.

Isn't that the Chevy Volt concept?
Yes it is.

Will we ever actually have the Chevy Volt? Who knows? But in the mean time, we can built it faster/better/cheaper in our own driveways.

PS: Please don't turn this into a conversation on the VOLT or EV-1, there are other threads for that!

Hey Tom, a Citicar would be an excellent candidate for range-extended hybrid conversion!

[drbobwoolery]

Reading this thread from the beginning, I wonder if using the mount/shift/axle setup from a 4 cylinder version wouldn't have saved a good deal of grief. They moved the transmission over to accomodate the fourth cylinder.
I am sure that many ecomodders have put these transmissions into their 3 cyl. models, and may have hoarded the parts not used.

I'm wondering about using a welding machine generator as an EV motor. These are a compound DC machine, so much or all of the control could be on the shunt winding. I believe these depended on the output bearing of the 1400 rpm Continental engine.
I haven't measured one, but would probably bea bit large for a Metro!
Also, a 40 hp electric motor would likely twist off stuff sized for 55 hp IC.

bob

[bennelson]

Hey Doctor Bob,

If I was building another electric Geo Metro, I WOULD start with a 4-cylinder model, as it does have the the transmission over farther, which gives you a little more room.

It wasn't a big deal using the 3-cylinder model, but it did just happen that I had the exact biggest motor that I could possibly fit in there, both in terms of length AND diameter.

I think it was a good choice for a motor and has been working very well for me. More and more, the car is becoming less experimental. It just plain works. I drive it and find myself thinking about design issues less and less.

The series-wound motor works great. A shunt-would (or compound wound) would be pretty neat in that you could use regenerative braking. Of course you would need a different controller, and it's a bit more complexity, be it would be cool!

[bennelson]

Hey Guys,

I think the Electro-Metro threw a shoe.

Kristin and I were coming home from the grocery store last night. When I pulled into the driveway and stopped there, I saw a small cloud of smoke from the front of the car. I thought at first that it may have been steam coming up from the driveway, as it was raining at the time.

But nope, it wasn't the rain. The burning smell gave that away. I checked under the hood - no melted wires, and everything was nice and cold, as usual.

Then I checked the wheels. The passenger-side wheel was very hot. All I can think of is that it must be a bad wheel bearing. If it were an issue with the brakes, I am sure I would have felt the drag.

What do I need to do to replace bearings on a car like this? Any other things to check for first?

On the up side, this is just a car thing - purely mechanical - it seems to have absolutely nothing to do with fuses, cabling, batteries, or anything like that!

[MazdaMatt]

Don't rule out brakes so fast. I'd say that is 90% your most likely answer.

Jack up that corner of the car and see if you can wobble the wheel, that would mean bearing (no wobble does not mean not bearing, though).l

You can tell by the smell if you're used to burnt brakes... spending time on a big race track gets you used to that smell.

[bennelson]

I just jacked up the car. The wheel does NOT like to turn.
(I am busy working from home today, I am trying to look at the car whenever I get a free minute or two!)

Next, I will take the tire off and see if I notice anything unusual with the brakes.

D'oh! I just realized that I am supposed to be showing off the car this Saturday! It would be nice to actually drive it there! I only have to drive about two miles - I am NOT renting a car dolly for that!!!

EDIT:
I pulled the wheel off. Preliminarily, it appears to be the brakes. If I grabbed the whole wheel, and tried wiggling it around, it felt good and solid. As far as I can tell, it looks like the brake pad is locked in place around disc.

[bennelson]

Yep, it was indeed a seized-up brake caliper.
The local autoparts store had a remanufactured one in stock.

I zipped over there on the electric motorcycle (now featuring cargo boxes!), had a good conversation in the parking lot with a chopper builder who actually saw me and then followed me to my next stop, and bought the new caliper.

Now I just have to install the thing, bleed the brakes, and my car is back on the road!!!!

[Daox]

Wooohooo, good to hear. And none too soon before the show.