Electric car conversion: Project ForkenSwift

[MetroMPG]

Too many projects!! (That's my new battle cry.)

[groar]

Originally Posted by MetroMPG

Let's call this the "A++/Hallowe'en 08" pack.

You are my other master, you logged around 666 miles in your ForkenSwift

Which is a big "woo!".

(I hear this old song "The Klf feat. Tammy Wynette - Justified and Ancient")

http://www.youtube.com/watch?v=SVM4UkQdR8A

They're Justified, and they're Ancient,
And they like to roam the land.
(just roll it from the top)
[...]
But if you don't like what they're going to do,
You better not stop them 'cause they're coming through
[...]
They're Justified, and they're Ancient,
And they drive an ice cream van.
(just roll it from the top)

Oops sorry : And they drive a ForkenSwift

Denis.

[MetroMPG]

You DO have an eye for spotting that number, Denis. Not sure what that means!

[MetroMPG]

While I'm working on an index of this thread (in post 1), I've been traveling backwards through time, re-living the project.

2 years ago this past weekend, we pulled the ICE out of the car...

(and sparked a minor debate about what's better, dropping it out the bottom or hauling it over the top)

[MetroMPG]

Used the car to go to astronomy class at the college last night. That's the last time I'll be driving it until spring '09. (sniffle)

Total distance driven since yanking the ICE:
>>> 2658 km / 1652 mi.

Total (net) build cost (latest expenditure: $175 for the Hallowe'en batt pack):
>>> $946.28 Canadian (give or take a few dollars)

[MPaulHolmes]

Originally Posted by bennelson

I think we could actually edit this thread, mine, and MPaul's to make a book.

"The Cheap, DIY, way to build an Electric Car: Learn from our mistakes!"

OUR mistakes???!!! haha! I don't know about you guys, but I'm pretty much perfect. There was that one time when I fed rocks to a blind old man, telling him that it was candy, and I guess I set the kitchen on fire by cooking the lovejoy coupler, but other than that, FLAWLESS!

By the way, I need to start keeping track of total distance like Darin, So I can get a mileage estimate for when the transmission or motor bearings go bad from crappy Adapter/Coupler fabrication techniques.

[Christ]

MetroMPG - are you considering doing any of the aero mods to this EV? I bet you could substantially extend your range by doing so... Even just the simple things... you don't need a front vent area at all, considering that ambient air cools forklift engines, therefore the whole front end of the car could be sealed...

We all know quite well that the rear of a Metro/Swift benefits from Kammback designs greatly..

Next, what about further weight reduction? Have you ever considered reversing the motor's polarity as a means of braking? If you could do that, it would eliminate the need for the braking system altogether, thus increasing efficiency and range further. (That is indeed alot of weight.) It's also one less pedal.

End-ride pallet jacks use this method to stop. You simply pull the controller in the opposite direction, it reverses the polarity in the motor, causing it to attempt to spin in the opposite direction. You would have the approximate potential torque of the motor stopping you, hence you would probably stop faster, although with a potentiometer-type controller, you could also vary your braking easily, as you can on the above-noted jacks. You would also save money by not buying brakes/pads/rotors/calipers/drums/fluid/lines/etc/yougetthepointbynow.

If not interested in motor-braking, maybe you considered adding a reclamation system to the current braking system? I'm not entirely sure how these work, other than converting inertia to electrical energy through heat absorption (I think).

Adding LED lights in place of incandescent for the turn signals, etc. would also be a help when it comes to both saving money for maintenance costs, as well as electrical usage. Plus, they can be had relatively cheaply, especially if you're into old electronics... computers have them. Plus, they'll at least last for the useful life of the car, meaning they'll never need replaced.

Another note on weight reduction, removing the factory wiring harness and stripping out the unused wires, as well as replacing the factory bushings with urethane (if it's available) will help with weight, and the bushings will help with handling, meaning you can safely corner at a higher speed, increasing efficiency. Weight loss can also be had by removing noise reduction material in the chassis, to the tune of ~30-50 lbs in some cars.

Obviously, if it's legal, plexi weighs less than glass... and the parts removed from the car could be sold to recoup some of the costs of conversions and additions/subtractions/modifications.

Given consideration to any of these ideas, the cheapest would obviously be the aero-mods, since you've already done some of them once, and could take information and results from that car, and duplicate them on this one.

The second cheapest, although not necessarily range increasing, would be the second idea... the reason I say it's not necessarily going to increase range, is that it takes battery power to slow you down/stop you. While you may not actually need to brake that much, since you can still slow yourself using gearing, it still might toll slightly more on the packs during normal use.

[Christ]

One more thing, if you're only using a few gears in the transmission, you could do something we used to do to the old redneck racecars... remove the excess gearing.

Like in the race pintos, we'd use a T5 5MT against a 2300 engine, but we'd always remove 4th and 5th and reverse. This leaves you with a 3 speed... if you need to reverse, you shouldn't be racing, we said.

We found out that not only does this remove weight, it removes ROTATING weight... thus frictional losses. The only thing you'd have to do is also block access to that section of the gear-shift lever, which you could either do in the car, or in the transmission. But since you're only ever in town, and it doesn't seem that you're using more than 1-3 anyway, maybe you could benefit from this...

Plus, as an added benefit, if you install a reversible motor, or a way to make the one you have do it, you' could get rid of reverse, and have all your forward gears for reverse gears too! (You could also have a super-low forward gear, if that would fancy you more, for heavy snow driving, etc... if you get stuck.)

Reverse + Reversed engine == forward movement.

Anyway, those are my thoughts... I'll inform you if I have more.

[MPaulHolmes]

They also make a reversing contactor so you can use 1st - 3rd backwards too. But that costs a couple hundred for a good one, and the whole car costs like $800. What sort of efficiency gain from less rotating mass would you get from just keeping 1st - 3rd (or in my case, just 1st and 2nd)? Normally a transmission/driveTrain is like 90% efficient, right? Could you bring it up to 95%? That's a very interesting idea, Jesus.

[Christ]

I forgot to explain that... rotating losses occur in manual transmissions because the gears (and their related shafts) are always spinning.. they're always in contact w/ the input shaft, regardless of what gear you're in... even neutral.

When you put the tranny in gear, you're actually engaging (via a lever) a set of "dog's teeth" to the side of the gear, which is attached to the output shaft, and causes the gear's motion to translate to the output shaft and eventually to the tires...

This is still rotating weight, but mostly in the same sense as a belt drive... it's parasitic. It still takes power (allbeit minimal) to turn those gears constantly, power which could otherwise be used for something else, i.e. propulsion.

The weight advantage comes from the fact that it is in fact rotating... it's like lightening the crank pulley.. less inertia.

Originally Posted by MPaulHolmes

That's a very interesting idea, Jesus.

Yeah, well... Christ actually is my name. LOL. Ironically, you're the one person on here that has a sig dedicated to people who don't think about their nicks...