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Electric Supercar

116749 Views 525 Replies 38 Participants Last post by  snowdog
Hello all,

I thought I would start a build thread. I have ordered a K1-attack kit car. I have started the assembly. My plan is to have a Tesla drive train. I am sourcing from EV-West. Hopefully that was a good company to partner with. I am waiting on batteries until the build is further along. I will definitely reach out to the forum for advice along the way. I am also documenting in YouTube. Feel free to follow along.
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I find it odd that somehow the positive plate wouldn't be isolated from the battery case.
There is no single "positive plate" in a module,; although of course the most-positive cell has positive side, it is not isolated any differently from the other cells. Each of the heat transfer fins which runs between a pair of cells and turns to contact the cooling plate is exposed to a different potential - each of them is positive compared to one neighboring fin and negative compared to the neighbor on the other side, if they are not completely isolated from the cells that they are cooling. If the fins where conductively connected to the cell terminals, any conductive plate clamped to them would be a short across every second cell of the module, and across the entire module. If the plates were conductively mounted to the frame, the entire pack voltage would be shorted through the frame.

The outside of each pouch is intended to be isolated from both terminals, but that isolation is not expected to be complete - there is certainly capacitive coupling, but there is also some conductivity.

In this design, which is widely used in LG Chem and other modules, there is no case between the cooling plates and the whatever surrounds the module. The modules are not intended to be exposed, but are supposed to be (as they are in snowdog's car) enclosed in a controlled environment, in contact with a heat-transfer plate using suitable materials (and those materials are an aspect which is being worked on). The "case" of the module is really a stack of retention frames, rather than a housing.
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Why use a yoke, unless you have less than one turn lock-to-lock of steering shaft rotation? Basically, if you can't safely and effectively steer the vehicle in all turns with your hands taped to the yoke, a yoke is not an appropriate steering control.

Tesla does it; that doesn't make it "cool", it makes it a marketing gimmick for people who don't really drive. Formula 1 race cars do it, and their tightest turns don't require the driver's hands move from their positions on the yoke.

An effective way to do this is to laminate wood segments around a flat metal core (like the spokes).
Superfast Matt's version (a wheel, not a yoke): Build Your Own Steering Wheel. Or Just Watch Me Do It. Whatever.
If it is to be entirely covered (as this is) the material choice is wide open, and it could be 3D-printed front and back halves around the structural metal core.

Why does it have a bottom? Because it's straight it's not very useful.
Clearly I am not as cool as SuperfastMatt.
Almost no one is. :)

Matt's wheel is not dished. To do a dished wheel by his method, I assume that one would need either a huge press, or to cut the spokes and rim as separate pieces and weld them together.

Why...To better see the gauge cluster and provide more leg room.
I completely agree that it is not as useful as a standard steering wheel. I may find that I completely hate it.
I would always vote for better gauge placement over omitting the top of the steering wheel. Although I realize that the dash and wheel don't line up well at the desired steering column position, a solution (even used in some production cars) is to mount the gauge cluster on the steering column.

Moderate flattening of the bottom of the wheel is a reasonable compromise, and is quite common.
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