[MalcolmB]

Ahem, yes, uh, I knew that of course ...

... another mince pie and a glass of sherry for me, Nurse

[Yabert]

How do you connect a second controller to a series motor and get reverse? You still have to reverse the field respective to the armature.

Eeeeeh!! scheize!!...

I haven't thinked enough before write my question.
The problem is the A2-S2 connection. I can put a small contactor (200A) between S1-S2, but I can't disconnect A2-S2 without a big contactor (1000A).
And 4 kilovac EV200 contactor cost 500$......

I can't believe it's that costly and complex to go in reverse!

[rwaudio]

The cheapest you could get away with are two big contactors to disconnect S1 and S2 then two small contactors to connect the field the other way.

There are some EV200's on ebay, I don't know the seller but the price is good.
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

Good luck!

[pm_dawn]

Hi !

Why not build a small friction drive, just like a caravan mover.
http://www.powrwheel.com/
Run it off 12v I vould guess a high quality cordless drill would do the job.

Regards
/Per Eklund

[caca]

Hello,

This is a great project and something like that I want to build. My dream car would look something like this;

- Smart 451
- Soliton Jr. controller
- Kostov new 9" 220V motor
- 69s5p Headway 40160s 16Ah, which is approximately 18kWh and 175kg

Yabert, I wonder if you measured the space for batteries, what are the dimensions of space. I plan to put the battery in this place.




My battery configuration





the entire battery pack would be about 600 x 800mm and 200mm high with battery box

[Woodsmith]

Originally Posted by pm_dawn

Hi !

Why not build a small friction drive, just like a caravan mover.
http://www.powrwheel.com/
Run it off 12v I vould guess a high quality cordless drill would do the job.

Regards
/Per Eklund

I was thinking of a small geared motor with a sprocket to engage the chain on my trike to get reverse. I figured in the same way that motorbike converted trikes do it. Might even get away with no controller, just a big switch, though a small 12v bike controller would do.

The other option I thought about would be a big double pole change over switch.
I'm sure you could make one with a rotary barrel, like they did on old electric milk floats, and it wouldn't need to switch a live current so no arcing to worry about.

[Woodsmith]

It occured to me, as I was in the shower just now, that I have a shed load of 200A-300A 440Vac switchgear.
I should be able to find parts to make a usable reversing switch on the basis that it only needs to carry the dc current but not switch it. It will only ever operate when the current is zero so no arcing problem. It can also have a built in throttle pot cut off to kill the controller before it breaks the contacts.

That maybe your solution to an affordable reversing switch too.

[nimblemotors]

Cool project. Why can't you fit a FWD transmission in it? Does the smart have an existing trans? A Geo Metro 5-speed is quite small and light,
you might even think of using an Automatic version so the manual shift linkage isn't an issue to get into reverse.

Why such a big deal to avoid using reversing contactors?
They are used commonly with DC motors.

[Yabert]

Originally Posted by caca

Hello,

This is a great project and something like that I want to build. My dream car would look something like this;

- Smart 451
- Soliton Jr. controller
- Kostov new 9" 220V motor
- 69s5p Headway 40160s 16Ah, which is approximately 18kWh and 175kg

Yabert, I wonder if you measured the space for batteries, what are the dimensions of space. I plan to put the battery in this place.

Really nice picture!!...

I will put all the battery at the same place. The Smart engineers will also put the battery box at this place.
The green area on your picture mesure aproximately 500mm x 1030mm x 200mm.

So you can't put 18Kwh of energy with todays battery technologies. I will put 48S 8P of headway 10Ah 38120S for 12.3Kwh and it's realy tight!

But your set up will be awesome with Smart/Soliton Jr/Kostov 220v and probably a bit less Kwh. If you don't need great performance you maybe can find less powerfull battery with a bit more wh per liter (more kwh for same space but less Kw).

[Yabert]

Originally Posted by nimblemotors

Cool project. Why can't you fit a FWD transmission in it?

Too big. The Nissan sentra Spec V transmission is really too big!

Does the smart have an existing trans? A Geo Metro 5-speed is quite small and light

They can not transfers 250-300 lbs-pi of torque produce by the motor.

Why such a big deal to avoid using reversing contactors?
They are used commonly with DC motors

Yes, but not at 1000A