Firefly Electric Conversion

[Stubby79]

Originally Posted by Thalass

Wow this is a great conversion!

You sure you're in the right thread?

Thanks.

Originally Posted by Thalass

With the motor brush advance, can the brushes be moved without disassembly? I remember a few years ago I thought of using a servo to advance/retard the brushes to match the required speed and direction. Probably not worth the effort, but you could have reverse without arcing and all that.

So far, I don't have any reason to advance the brushes. Of course, I haven't revved it up. I understand that arcing can happen if the field is too weak, but that shouldn't be an issue with this motor. We'll see.

I also have little reason to reverse it, since I've got a transmission, though if I wanted it, it would be as simple as flipping the field polarity.

[WyrTwister]

Please forgive me . I know very little about electric cars and a lot of what you have described went over my head .

Is the charging circuit built into your controller ? Or is the charger a separate device ?

You spoke of battery weight and weight distribution . How will this impact your front wheel alignment ?

I think you mentioned motor heat . Can you duct air from the front grill area , to flow over the motor ?

Do you live in a climate where you will need a heater or A/C ?

Thanks ,
Wyr
God bless

[Stubby79]

Originally Posted by WyrTwister

Please forgive me . I know very little about electric cars and a lot of what you have described went over my head .

Is the charging circuit built into your controller ? Or is the charger a separate device ?

Separate.

You spoke of battery weight and weight distribution . How will this impact your front wheel alignment ?

My conversion's weight will only be a little over the original car's weight. Won't change anything, unless I fail to distribute said weight properly.

I think you mentioned motor heat . Can you duct air from the front grill area , to flow over the motor ?

I can, but I doubt I will. Might end up ducting water right in to the motor!

The motor has a built in fan. If I need more, I'll add some forced cooling. I shouldn't, though.

Do you live in a climate where you will need a heater or A/C ?

I'll need heat for defog and or defrosting in the winter (rainy season). I need AC about 2 days a year, so I'll live without.

Thanks for the interest.

[WyrTwister]

Sounds like you are doing away with the clutch & coupling the transmission shaft directly to the motor shaft .

Will you have some sort of " kill switch " to remove power from the motor , for neutral & gear shifts ?

As far as vacuum booster for brakes . If you employ an electric vacuum pump , I would think the larger the vacuum reservoir , the better ? With a check valve between the vacuum pump and the rest of the system ?

I think you said a lead acid 12 VDC battery for the field circuit ? That would work to power the rest of the car's " standard " electrical system .

If you have enough room , you could even mount a pulley on the " back " end of the motor & use a belt to spin the original alternator . Hook up the stock wiring harness .

Do you plan to use 240 VAC to power the charging device ? 120 VAC would be more convenient , but a 240 VAC input would probably give a faster charge ?

God bless
Wyr

[JoeG]

You will love your converted Firefly. I have a 1991 Geo metro with a 9” Advanced motor FB1-4001 running on 45 Lifepo4 cells. It’s been my daily driver for 4 years now and I love it. I just put in 3rd and go on surface streets, shifting to 4th for the FWY. You should be able to do the same with your 8” motor also. About motor brush timing, at higher voltages(96V) it is done to keep the brushes from arching. Check out the attached EVDL post, [EVDL] Advanced Timing speed/volts chart, best setting for daily driving - DIY Electric Car Forums . My motor was shipped with neutral timing. I removed the 4 bolts holding the end bell on and rotated the bell to line up withthe advanced set of holes to advance the brushes.
Happy Motoring
Joe

[thingstodo]

Originally Posted by JoeG

I have a 1991 Geo metro with a 9” Advanced motor FB1-4001 running on 45 Lifepo4 cells. It’s been my daily driver for 4 years now and I love it.

Do you still have your clutch or did you get rid of it and go with a direct coupler?

What controller did you go with (voltage and amps)?

[JoeG]

I did away with the clutch. With a large motor(9 dia"), & light car, you don't need to shift much, since they are torque monsters. With a 7" motor, you need to use the transmission like a gas car to get any kind of acceleration. My controller is a self built Open revolt controller kit. It's good for 600A and up to 160 volts. I'm running 45S or 154 volts right off the charger.
Cheers,
Joe

[EVmetro]

Originally Posted by MetroMPG

I'm going to respectfully disagree with that sentiment, and EVmetro's. I drove the ForkenSwift for ~6 years with no boost, but if I were doing it over I would add boost. I would say safety is marginal without boost.

I would say that the deciding factor that makes boost a must would come down to lead vs lithium. Trying to stop a lead sled with no boost would not be fun. Boost is still nice with the much lighter lithium pack, but not exactly essential. I use vacuum boost in my own Metro builds, but I also equip those systems with switches to turn the boost on or off.

[JoeG]

I don't have vacuum boost on my metro either. It stops fine, but I'm a 195lb male, with strong legs. It takes all I got to lock the front wheels, where with the vacuum assist, anybody could. If my 16 year old granddaughter was going to drive the car, I would install the vacuum pump that I bought 4 years ago & never bothered to install.
Joe

[thingstodo]

Originally Posted by JoeG

I did away with the clutch. With a large motor(9 dia"), & light car, you don't need to shift much, since they are torque monsters. With a 7" motor, you need to use the transmission like a gas car to get any kind of acceleration. My controller is a self built Open revolt controller kit. It's good for 600A and up to 160 volts. I'm running 45S or 154 volts right off the charger.
Cheers,
Joe

Sorry to hijack the thread. Thanks for your response.

Good to hear you get good performance from no clutch. 600A is likely more than I will be using - I will be closer to 220A (4C from 48V of 55 a-h leaf cells) and either a Cougar controller or the newer IGBT version.

I would like to build (along with the other projects that I have) a side-by-side utility vehicle, use the motor/transmission/CV axles/front wheels from a 90 sprint and transplant that into the rear of a home-built side-by-side for some minimal off-road/utility use on our acreage and to move people. Using the transmission for reverse and likely only first and second gears for forward. Shifting would likely be done when stopped but could be done clutchless while moving .. maybe. Anything else I can use, I will - like the manual brakes, seats .. maybe headlights?

The 90 chev sprint project ... I bought it *VERY* used from a machinist that got the transmission coupler done (it actually uses a joy coupler!), the transmission adapter plate, and sourced an old sepex aircraft generator for a motor.

I would normally avoid sepex, but the generator/motor is only about 7 inches in diameter and at 48V it likely won't over-speed even if I run it unloaded! I plan to run the field from the 48V pack with a resistor in series to limit the current. If there is no current through the field, a relay will lock out the armature controller.

If I ever get there (many projects) I will post a build thread.