Geo Metro plug-in parallel hybrid EV - in progress

[Coyote X]

The weather isn't quite here yet but it is close... Yesterday we had a few more inches of snow and today was like 25 degrees all day. Tomorrow is going to be near 50 though so

I can't see anything online that is bad about the motor/controller combo I am planning on using so I am going to order the motor tonight and hopefully in the next week or two I will actually start building things. I was going to order it yesterday but I just got a copy of orange box for the 360 and it needed playing

Also I took an axle to school and talked to some engineering types and I think I have a pretty easy to make plan for getting a sprocket on there. If things go smoothly I should have it done and working by geopalooza so everyone will get to see it in person.

[Coyote X]

Motor came in today. I will start messing with it this weekend and see what I can figure out. It is a bit thinner than I estimated so it should have no trouble fitting in a few different places.

I saw Kelly controllers has a 144V controller now. Is it worth spending double the money to get a 144V 650A controller instead of the 72V 300A I was planning on? I doubt I could fit 12 batteries in the car easily but I guess anything is possible. Is going to 144V actually worth it though in real day to day use? If anything I guess I could get that controller just so I have the option of going higher voltage in the future. Not sure if that Mars motor can take that much abuse though.

[Coyote X]

was looking at the dc controllers this is the one I should be looking at:

KBL12401H,24-136V,400A,BLDC Controller/With Regen

So that still lets me go to 120V 200A continuous. Still more than the mars is rated for so I am not sure it would handle it.

[MetroMPG]

So you didn't order the low voltage AC motor kit with regen? Regen would be cool. You can't coast up to every stop.

[Daox]

I'd recommend staying away from Kelly controllers. Just by word of mouth. We have a guy running a 144V S-10 around here. His Curtis 600A controller works better than the Kelly 1000A he used to have.

[Coyote X]

I ordered the motor directly from mars electric. That robot marketplace has insane shipping rates. I can always get that 48V controller later but from what I have seen everyone says go to a higher voltage to get more reasonable acceleration rates and top speed, plus it reduces the amps required. I am not really sure what controller to get though that is why I haven't actually ordered one yet. I always have the option of making my own but I really don't have the time to deal with it.

Just about all the AC controllers have regen braking so I will be able to use that no matter what. I have not seen anything over 48V other than the kelly controllers so I don't see a lot of options if I want to run 72V for now. I still have to get the motor mounted and a chain drive of some sort figured out so I have a few weeks at least to decide on the motor controller and voltage.

For the chain drive I have seen some specs on the motor saying it has an absolute max of 4000 rpm. So with my 175/70-14 tires I need a 3.9:1 ratio to allow the car to go 70mph without overspinning the motor. The best I can come up with is an 11 tooth 7/8 bore sprocket from that robot marketplace($18 shipping!!) and a 42 tooth from tractor supply for the axle. That is using a #40 chain so it is a bit smaller than I would like but it is about the only thing I can come up with that fits in the space. I can go to a max 3.75 inch diameter sprocket on the axle without hitting the lower control arm. That pretty much limits my options using a #50 or 525 chain since they would be a bit too big, so it looks like a #40 will have to do. Unless anyone knows a good place to order sprockets from that has a pretty good selection

The Metro axle shaft is 7/8 so it isn't going to be that hard to find a hub for it. The drivers side has lots of room for the motor and I could probably grind the flange on the control arm and get another quarter of an inch or so clearance if I need to go slightly bigger but it still won't let me go to something like a 38 tooth 525 without hitting. My only other option would be to put a 13-15 tooth gear on the axle and a gear reduction sprocket set somewhere to gear the motor down. That would be a lot more stuff that could go wrong long term since it would be 2 chains, 4 sprockets, and 2 extra bearings. I might have to do it though if the #40 chain won't hold up to long term use.

[bennelson]

I ordered my custom rear motorcycle sprocket from Sprocket Specialists.

I'm running a #40 chain on the motorcycle - just a plain cheap chain from the tractor aisle of the farm store. They also had pretty small sprockets at the farm store as well. I got both a 12 and 14 tooth sprockets there, and a 72-tooth from Sprocket specialists for a 6:1 gear reduction.

[MetroMPG]

Want me to rename the thread title?

I figure if you're actually spending money, it's progressed beyond "questions".

[brihoo2k]

Just a thought but how about going with a belt configuration like a cvt (constant variable transmission) you could possibly rob one off a snowmobile. I myself would not consider the size 40 chain unless it was double roller. Also are you mounting the sprocket in a stationary spot on the axle, one that doesnt move with the suspension. Does the axle have a mid bearing to keep it stable? It's been a long time since I've worked on a metro so I'm not sure.

[Christopher Jordan]

Pretty old thread; but last year I was offered a trade for an electric Metro for my City-el. No thanks, plug-n-go- I don't know. Just last week I saw that same Metro in Craigslist with an 'as-is, doesn't move' warning about motor to axle connection grinding out.

There must be an EV God ! City-el is way over-amped, is about 77 pounds over the limit, exceeds top speed and acceleration- so has less range, very tricky charging; but took it out yesterday on highway 1 (in-town) with no problem.