Bob's EV SLC Build Log

What fun car did you get? I had a lotus Elise which was lots of fun, best handling car I ever had.

I really was very naive on the electrical conversion, I figure a few handmade brackets and some wires LOL. But then again I was also naive on the time it has taken to complete every stage of the project. The fun part for me is getting out of your comfort zone and learning new things and skills. Looks like you are doing plenty of that and then some. Keep up the good work and keep posting your progress.
 
I picked up a r8 spyder, v10 gated manual. It has a twin turbo kit on it. Very fun, summer only. I bought it as mostly an investment, but it's too fun not to drive. Wife is not happy with how loud it is. We have been a full electric car household for about 4 years, and she does not miss the sound of turbo ICE. Probably going to have to build a valved exhaust system for it over the winter.

I could have done a much easier swap with only a single tesla drive and stock automotive batteries, no suspension modifications, but this would have basically been a a tesla model x or s. I cart the kids around in a model x, so wanted to push the line. There are some very good tesla swap logs on YouTube.
 
Hey good choice, same Graziano and gated shifter I have on my SLC , hopefully will shift nicely. I got rid of my super loud Nissan GTR, no cats and extra loud exhaust, my neighbors are happy that now I drive a Honda Clarity plug in hybrid, super quiet in electric mode, big change!!

I probably would have gone the easy route with a single drive, but glad you are pushing the envelope and paving the way for others, maybe I will follow you later. Document well :cool: and keep all those CAD files.
 
sort update. I recently picked up some new tools to aid in the fabrication. The delay using 3dhubs to get parts milled is just not tenable. I picked up a artech 3d scanner, a hytb5 5 axis mill (cheap Chinese desk top mill), and a shopbot buddy cnc router. Just got them all setup and produced my first part, a new rear caliper bracket to hold carbon ceramic rotor. I scanned the old SLC one in, and was able to modify it to accept the the new rotor, and keep the spacing correct. Images of the rotor, caliper sitting on the upgraded bearing. Still have to fabricate the mount for the tesla parking brake.

Also in the images you can see where I am going on the suspension system. I have moved the location on the dampener, changed the bell crank to get more travel out of the dampener, and linked it up to the rear torsion bar. I am experimenting with a hydraulic piston as the linkage, and seeing if I can use feed back from laser sensors on the bottom of the car to control ride height, and hold everything level, always. Not quite ready to talk about the suspension system yet, waiting on some airshocks to come in.

The scanner is a real help in all this, but has a very steep learning curve. I just scanned in the face of the inverter than i have to dsign a cooling manifold for. It gets the position of holes correct, but they are always smaller than actual.
 

Attachments

Curious as to whether and how you resolved the gear lubrication issue due to running the drive upside down. Looking at a Tesla swap project and contemplate running the drive (single in this case) upside down.
 
So I have not opened the drives yet to swap out the gear sets and replace the open diff with locked differentials. This is getting done when I pull everything off and the chassis goes out to get the drive assemblies welded on. But my plan is to remove the internal lubrication pump, and replace it with and external circulation pump, scuffer pump, reservoir, and heat exchanger. I will drill and tap the side of the case with 1/16 ID swage fittings, to have the lubricant hit the correct gears, and add a large 1/4 or 1/2 ID fitting for the drain. The drain will probably be on the side of the case too, but I haven't drawn it all up yet. Flow rates are in the ml's per min, so the pumps do not need to be large.

For the record, I'm not the first to try the inverted drives. https://www.facebook.com/DRIFTECH1/photos/pcb.2551848938216003/2551847671549463/
and
for more detailed description.

Inverting the large drive makes sense and you can get the heavy part of the drive closer to the ground.
 
Oh a real big one is coming. I have been hard at work building a solid workshop for myself. The warehouse I was using had to start being used to actually store things other then my crazy projects. So, the wife decided to let me convert our abandoned/failing carriage house into a workshop. I suspect the thought of me spending weekends off site at a contactor bay instead of within shouting distance figured into the financial calculus. So 5 months, a whole lot of digging, and a big load of cement, and I have a functional but rough 3 story shop; 1600 sqft one two floors with 800 sqft of loft storage (now very cold, but inside). Its kind of a life long dream to have all this 8 steps from the back door. Been consolidating all my tools and all my projects into it. In the process I some how built a respectable hobby machine shop. I decided to stop out sourcing everything, and to finally learn how to machine parts. As usual I have gone down a bit of a rabbit hole. But I finally have most of the major tools I have always wanted; Solid drill/mill, 2 axis cnc router, tiny 4/5 axis cnc route, laser cutter, markforged 3d printer, cnc lathe oh and the thing I should have bought 2 years ago...a solid 3d scanner. I could have saved weeks of time if I had it when I started the rear. Only thing missing is a good "garage" cnc, but honestly I'm not far enough along on the learning curve to make the jump. My little chinese mill and the shopbot are doing the work. Machining is many steps up the ladder from laser cutting, and that is a few above 3d printing. But I have my feelers out, it will be a tormach... just want to find one that's not 1500 miles away. I will do a shop tour soon. I still am outsourcing some laser cutting, but just steel at this point, I can do pretty much anything in aluminium. With a better mill I could do the steel too. I also am not welding yet, but I will learn that at some point, my slate if full right now.

As for the car, I am machining the parts for the rear end as we speak. Its alot! 3 sets of Bell cranks, caliper mounts, parking brake mounts, air accumulator mounts, rear steer actuators, hydraulic accumulator mount, hydraulic pump mount, shock/pushrod travel sensors mounts, and all the mounts for the swag rods triangulating the motors in. Not to mention I have gone through probably 8-10 revisions of the suspension system in CAD and wood mockups. But I am at the point where everything works, everything clears and bolts together. Just need to get it all in metal now.

Bob
 
I will have to run 3 HV AC lines to motors from the inverters, jumpers for the sensors, and come up with electrical sealing solutions for the inverter and drives, all will be 3d printed to fit. A company in NH has adapter plates for the motor and the inverter to give you the mechanical and cooling hook ups for the units. They are early prototypes, but they have installed them on at least one other vehicle.
Bob
Hi Bob,

Several of us over on DIYElectricCar.com are interested in blockoff plates, as well. Mind sharing the name of the company, or if not cool from an ad posting perspective here, PM'ing it to me?

thanks!

ps I joined not merely to ask this question, but just found out about this august group and it's impressive what you guys are doing here. Hopefully can contribute to problem solving and ideas.
 
@Bob Wind, it looks like your are having a space problem up at the front of your SLC. Can this solve your problem?

ba268438f4e45d8e_800x800ar.png

image from Koenigsegg

Road & Track magazine says about the motor (named "Quark" by Koenigsegg) " . . . 335 hp and 443 lb-ft of torque in an amazingly compact unit: The complete motor weighs just 63 pounds . . . "

And, Christian von Koenigsegg wants you to have it. He says " . . . it just makes sense to share it as they're very modular and can fit many different needs." And "the company will license the motor design to interested parties."

Hope this will help you. Here is a link to the article: How Koenigsegg’s Tiny, Ultra-Powerful Electric Motor Works
 
It's nice he wants us to have it, but I'm guessing he wants money for that motor.

How much is it and what are the voltage and current specs? Torque curves? Data sheet?
Here is the information I was able to glean from Koenigsegg's website:

Koenigsegg Press Release

Koenigsegg Quark Electric Motor Data Sheet

And they have another, less expensive (I think) motor they call the Terrier.

a8a32f5dd463c324_800x800ar.png

image courtesy Koenigsegg

Koenigsegg Terrier Electric Motor Data Sheet

But I can't find any prices, yet. :)
 
That wasn't a datasheet, it was press kit talking points.

Like the Tesla motors, peak power is merely a brag. With the low weight, I'd be surprised if its continuous rating is very much north of 100kW, if even that much.
 
Hi guys,

sorry I have not been getting alerts in my email from post activity. Quick answers to some questions.

On block off plates, I have designed my own. I have only done the one for the drive itself, not the inverter. I 3d scanned the drive face, took a section and made the plate from that. I have it in nylon right now, to check fit, and it went on like a glove. I pick the tormach up next monday....the back log of parts is deep and its in there. I can share the DXF if you want it. I need to work out the inverter still. I cant decided to do one large plate that will attach over the end of the inverter "bucket" and seal both the bucket and the inverter, or do one out of aluminium and the other out of CF. That is a down the line problem for me. I am under a big push to get the rear fully done, and get the front on. The big drive issue I have right now is the 4.5:1 gear sets are "under redevelopment" by quafi, guess there has been issues. Glad I didn't buy a set, but I'm not cracking open the drives until I get a set. I have my "dry sump" lubrication system for my rear drives all spec'ed out, just need to open them up and replumb.

On batteries! Oh Batteries! The longer I wait the more options crop up. I have gone through a major rethink on them. I need a fantastic amount of amps....like 3200 peak or so at 400V. As I started to design the system getting fuses, connectors, wires, ect...that can do that peak amps, well they are not really available at realistic prices, and they just become huge. So, after a night of drinking and auguring with some EE's. A New Plan (ANP) was arrived at. We will split the pack in half, run 2x 37-40 KW, 400V 1550 max amp packs. Basically drive one large and one small drive with each pack. That way we can use all tesla fuses (the new ones are engineering works of art), tesla connectors, tesla wires, ect you get the picture. Everything, including BMS's basically get duplicated. Now there are down sides....one pack running out first being the big one, but unless I am oval tracking it, that really won't be a thing. Plus the cool thing is I could pull into charging stations an take both chargers.....which is just cool, like guys using 2 pumps to fill up lambos.

I am leaning very hard towards using high discharge 18650 cells, to make it work I need a minimum 25 Amp Peak cells, ideally 35 peak. I know these are touchy cells. I am going to be running them in immersion cooled packs, some what like Xing is doing . I have a 4 different cells that I will be building into a immersion cooled packs to test drain and cooling on. The cylinder cells have more structural integrity, and lend themselves to immersion cooling much easier. I will be doing cell level fusing like tesla. My buss plate will be different, as I am using it to seal half the cell.

Finally, the Konig motors. Yes, saw them and my read is they are axial flux motors errierly similar to a 1.5x the yasa 400 motor. they are still ~300 mm x ~300 mm thats not that small, and the cost of 2 of them with inverters is probably 70-75K min. Other problems....850V motors, 9000 max rpm. That voltage kicks you up a class of connectors, wires, fuses, ect, and isn't really compatible with the tesla stuff. If you don't want to play with 850V, and look at yasa's torque curve @ 400 V, you see peak power only 85 kw, at ~2500 rpm, and torque starts dropping right around there. you then decide to stuff 2 tesla drives up front. Hell if you are only trying to get 2x 100 kw motors upfront,, lots of good options out there. The I3 motors look real interesting. With a 9000 max rpm on the Konigs, I suspect one will only be using about 1/3 of the power range, and never see peak power. I mean really 20 inch rim wheels are only going what 1100 rpm at 100 mph or so. So unless they have some magic thin gear box on them, I think they are only going to be really helpful off the line, and not at the top end. But don't quote me on that. And you really dont need 2x 370 NM of torque in your front end off the line, there is almost no way to keep it under traction without slicks or glue paper surfaces.

There was a company that supposedly has geared axial motors ready to launch. If it happens it could really be a game changer. Still the cost will be crazy until someone start making 100K of them every 90 days, and we can grab them from the pick and pull.

I was going to post pictures of my rear uprights with the new hubs and carbon rotors coming together, but that will have to be tomorrow. I machined them all and have everything bolted up. They look great, but somehow I bought the wrong half shafts for them.

Bob
 
I looked at immersion cooling 18650's. That pesky cell vent is not hermetic, which means possibly washing out electrolyte...
Hence the testing :) Xing is doing it, so there is a way. I don't think the electrolyte is missiable in the Dow fluid, and unless electrolyte weeps out under normal use, I don't think there will be enough pressure from the fluid to cause fluid exchange. My plan if it was an issue was to o-ring the ends of the cells and not flood the ends, not as elegant thought. My worry was sparking from a cell fuse blowing in the liquid....
 
Yes...o-ring. Several thousand of them. None will leak.

The coolant is heavy & not cheap. Then again, if you o-ring, might get away with water/glycol?

Note that your cell fuse is also cooled, lol
 
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