Ya Gotta Love Panel Beaters

The guard on my car needs a fix after a bump – oops – a simple job one would expect, but shopping around for a good panel beater is difficult as most don’t want to guarantee their workmanship on anything that could bring on the slightest hint of rust. I have a spare guard but it has spot rust in a corner. The little dent can be hammered out and re-sprayed. A recommended panel beater turned out to be indolent and over six weeks promised the world and offered nothing, except personal comments about my looks, boobs, etc. I’m lucky I guess; a friend left his EV with a panel beater recently who drove it around happily, not caring for the ‘fuel empty’ alert and in so doing, wrecking a couple of the batteries.

It’s a bit of a battle in a bloke’s world – whaddya do? Anyway, at least Nathan is good at cutting holes and has done an excellent job on the car – he knows what’s important and takes advice on-board instead of saying ‘I know better than you’ like a lot of fellas do. As he’s said, we’ve both learned a lot in the past year.

Bodgy mounting? No, because it's mounted on the inside firewall and easily accessible.

‘Mounting my Charger’

Me being a picky, persistent and annoying person at times, (okay okay, often), I didn’t want the Zivan to be mounted somewhere awkward and intrusive. The shape of the car is restrictive but clues on where to place stuff were staring me in the face. Some time ago I said, why not mount it in the pillar? After some research and legality-checking, Nathan agreed it could be a good place so I mocked up a dummy Zivan. Always mock up components if you have space issues! The Starion pillar has a kind of natural venting which is assisted by a small fan. It’s still easy to reach the Anderson connector should I need to. Oh, and the DC-DC is mounted on the opposite pillar – neat.

Echo and the Funny Men

While my car waits for some final parts, the Echo conversion is progressing well and we hope to have it drivable very soon. There’s an EV show coming up and the Echo will be perfect for it, taking pride of place amongst the smaller vehicles and some funny guys riding funny go-carts etc – yet demonstrating what can be done with the new generation of lithium phosphates. Small cars will be a big feature, with lots of folks contending for the ‘smaller is better’ stakes – hah-hah.

Like the Getz, the Echo is reasonably easy to convert (and a lot easier to work with than the angular confines of my Starion) and if such things were mass-produced as EVs to start with, the price would be a lot lower than a converted car (in fact comparable to a gas equivalent).

Time to Look at Curtis Cooling

Although mentioned previously, we’ve had to put it aside while working out where everything else is going to fit. As you know, the Curtis has a bunch of MOSFETS inside, ‘sinked’ to the base of the housing. Although efficiency can be improved in a controller design, simple immediate solutions can involve better cooling. Some folks attach the controller to a suitable flat metal surface on the car which in effect becomes a giant heatsink while others add fan arrays on top, or do both. Chunky Curtis heatsink fins are also available.

With space at a premium, a flat aluminum cooling block is used instead, fixed to the underside of the controller. In my case, the cooling block has been made to sink the heat from this area with the help of conduits drilled through the block for coolant ingress.

A pump is used to circulate coolant through the Curtis and my old interior radiator, with a return hose to the pump and an overflow reservoir with possible expansion valve (we are yet to test expansion for this amount of coolant; some thoughts below). The block itself is screwed to the base of the Curtis and thermal heatsink compound is applied between the surfaces, such as good quality silver compound for high thermal conductivity. At present it’s just a chunk of aluminum; I wonder if it should be anodized to 5> microns for better heat sinking? Better still, a block fabricated with an optimized fin-array would be nice but that may be over doing it. I have a couple of other ideas about flow but haven’t CAD’d them up yet.

Anyway, liquid cooling is much preferred over affixing bulky fans and jutting heat sinks, and is more effective. If there was room, both options could be possible, with a temperature sensor to cut in the fans – but correctly-configured liquid-cooling may negate the necessity of added thermal solutions altogether as it should allow extended peak times under load and therefore higher continuous operation – great for those steep hills etc.

Pump Action

What type of pump? One that’s typically used for water-cooling fast processor chips, from Xoxide. It’s pretty robust and will run off the accessories. Clear hoses will be used so we can see the coolant.

Not much to look at, but simple and well built makes it last.

Cool DC motors for Electric Vehicles – Kostov Elprom-EMS in my Starion EV

A lot of people are asking me where they can get the DC motor known as the Kostov. If you’ve found it difficult to obtain a Kostov, then you’re in luck; Elprom-ems, a Bulgarian motor company who have long been making fork-lift motors are stepping up their production of AC and DC motors specifically for the EV market.

Some of them are big mothers, able to handle over 95kW comfortably with a Kostov 10.7 inch delivering around 30hp continuous and over 180hp peak. From close inspection of the one I have, they appear to be ruggedly built, like a Vostok one could say – ‘bullet-proof’ as others have said and I can see why.

Elprom Kostov DC Motor.