[Jan]

I am seriously jealous.

About AC vs DC. I think the situation in Europe is a little different:

http://www.electro-vehicles.eu/shop/...duction_Motors

AC is a bit more expensive per kW, but not so much as in the US.

[Thaniel]

A very unique vehicle. Seems car and driver did and article on this vehicle when the movie came out. I've seen it before somewhere anyway.

Have fun you have an eye poping vehicle.

[PhantomPholly]

Awesome wheels!

...and here I was expecting a man with a tape recorder up his nose!

[Fireman_Mike]

Originally Posted by SimonRafferty

Cool vehicle choice! I've always wanted a 101 - but just don't fit in them (too tall). I saw the Judge Dread vehicles at the Billing Land Rover Show years back and have often wondered what happened to them.

Except for a couple retained for publicity, they were sold off in bulk after filming was completed. Most of them had the Dredd bodies removed and destroyed, and were converted back to standard 101 GS spec. and sold. A couple got used for publicity/show cars by other companies (google 'vibe dredd'), maybe 7 or 8 survive with their original bodies. There were two others road-legal in the UK. One got sold to a noted Land Rover dealer in France, the whereabouts of the other is unknown.

Some backstory on the building of the cars here:

http://www.surreyoff-road.com/judge_dredd_1.html

Mike

[Fireman_Mike]

Time to dust-off this thread. A bit of a hiatus over the last couple of years, during which I acquired a *second* Judge Dredd vehicle (!) and finally had it delivered to my door in NY a couple of weeks ago.

I'm now planning how to take this forward. A good thing is that the engine and gearbox are already stripped out, so I have clean sheet and an empty box to start playing with. I'd be interested to get some advice, and answers to a couple of specific questions on this project.

First, the design parameters:

1. Top speed not to exceed 50-55mph (it's scary enough already!)
2. Given the relatively modest top speed, and the wish for simplicity in build and operation, I've made the firm decision to go with direct drive; no gearbox.
3. Curbside weight as built was around 2000kg. It's lost engine, transmission, radiator, and most of the bodywork so current weight is several hundred kg less than that!
4. Target weight is whatever.
5. Target range is as long as reasonably achievable.
6. It won't be a daily driver, but it will get used on the highway.
7. The ultimate goal is a series hybrid, with power coming from batteries, and a gas turbine generator (think EV1). It should ultimately be capable of running from either or both power sources. The turbine being capable of charging the batteries is not required but is desired.
8. The initial goal is to get the vehicle running as a pure EV, with the turbine series power capability being added later.
9. I am at this stage agnostic regarding battery technology, AC versus DC, 50Hz versus 400Hz.

First, does anyone have any comments on my thinking above. 'Crazy' and 'ambitious' are redundant; I'm well aware I'm both.

Second, can anyone recommend resources - websites, forums, project blogs, manufacturers, distributors - where I might get some background, technical information, and war stories, specifically on DIY series hybrids?

Third, can anyone tell me if there are any controllers or power systems available off the shelf that cater for, or are especially suitable for, series hybrid applications? I have little idea at this stage how to go about blending and matching generator voltages & currents versus battery voltages and currents, and switching between the two!

Thanks

Mike

[SimonRafferty]

Dear Mike,

That's fantastic! I love the Judge Dred vehicles - and they almost deserve to be Electric, at least in part.

Did you buy it from Dunsfold? They are about 10 miles from me.

If you need Land Rover bits, I can recommend my friend Justin Monin who runs Lucky8 Land Rover in Williamsville NY. Anything he doesn't have I can get shipped to you as I run a Land Rover spares company.

I've been thinking about building a Hybrid Range Rover Classic using the AC drive from my Freelander plus a Peugeot diesel engine, both driving into a Suzuki SJ transfer box. The eleccy motor can drive the PTO output and the engine via an auto transmission into the input. That way you can mix the output of the gas and electric engines easily.
I rejected the idea of an engine driving a generator to charge the batteries because of the conversion losses. I love gas turbines - but even still.

I think the most economic solution is to charge the batteries off the mains, run on Batteries whenever you can, but switch to gas when they are getting flat - but not bother charging from the gas engine. That gives infinite range with the economy of electric. The Peugeot diesels are economic but too small to give decent acceleration so I figured using a 'kick down' switch which powers up the electric if you floor the gas pedal running on diesel to give the acceleration when needed.

Keeping a transfer box, even a small, light one like Suzuki keeps the 4x4 capability when required. The Suzuki boxes are normally rear wheel drive with selectable 4x4 which cuts the transmission loss a little.

My Freelander weighs 1.5 ton but still manages a top speed of 93mph and 0-60 in 8.5 seconds which is fairly respectable. Combined with a small diesel it should give respectable performance in a 2 to 2.5 ton vehicle.

Si

[Fireman_Mike]

Thanks for that Simon.

I'm in the USA so UK LR spares are not very helpful to me, but hopefully I won't need much!

That's exactly my thinking on why having the engine recharge the batteries is strictly optional... motor home on the engine if needed, plug it in overnight. Job done.

I have no interest in 4x4 capability for this; the LR chassis just happens to be what the thing was built with. I have the choice of FWD or RWD, and that will be decided entirely on the basis of ease of motor mounting and layout of the rest of the components. So no gearbox or transfer box, straight motor drive direct to the axle - heck I'd even consider an axle-hung motor with the drive going straight into the diff. to avoid the need for a shaft.

I've read of TransWarp motors, supposedly specifically designed for direct drive applications; any thoughts on those?

Mike

[Stiive]

Cool project, love the look of that thing.

For your conversion I would recommend AC.
You get much higher RPM which is good for direct-drive, and good torque overload at low RPM. Plus AC should be alot more efficient.

But the main advantage in that beast would be regen, with all that mass you get a lot of kinetic energy just waiting for you to convert back into electrical energy during decel. Could save you a lot on your Battery Pack Sizing.
Seems such a waste to accelerate that hunk of metal and then waste all that energy on your frictional disc pads when you need to stop again.

[Stiive]

Originally Posted by Fireman_Mike

The thing is a huge box - I could probably fit six battery packs where you guys are struggling to fit one, and hardly make a dent in the interior space available.

If space is not an issue, get a massive industrial motor like this:
http://www.ebay.com.au/itm/140333768...84.m1423.l2649

170kW, then rewind for delta to get some extra power.. Should bring it up to near 295kW (*sqrt(3) i think)... Burnouts anyone?

The motor probably weighs a tonne on its own though :P shame

[SimonRafferty]

The main issue you are going to have with direct drive is the motor torque available from the kind of motor you can fit in to the truck is not sufficient.

I found I needed a reduction ratio of 9:1 to the wheel with a 26" Wheel. Your Diffs will be 3.54:1 and likely your Tyres will be 31" or 33" - so you are going to need a further reduction of about 3:1 to give a good combination of acceleration versus speed.

I'm using a transfer box for nothing more than the 2:5:1 reduction in low range. I don't even have 4 wheel drive - though I wished I had in the snow this winter!

The Range Rover project is based on the 1.6:1 reduction in the transfer box plus another 1.5:1 chain reduction from the electric motor.

Si