Well at least I have half of it figured out. Today’s part is the brakes — the rear brakes, since the fronts are still stock. I haven’t quite decided what I’m going to do with the fronts yet, but the rears are in the bag, and I think they look pretty cool. These are zinc-washed Wilwood disk/drum brakes with vented, slotted and cross-drilled rotors, and four-piston calipers.
One of the four main components of an electric vehicle is the controller, which sends power to the motor as you request it with the throttle, instead of all at once. In the same way that fuel injectors spray metered blasts of fuel into your engine, instead of having the spark plugs mounted in the fuel tank. The way this is done today is with semiconductors, but it was once done with switches. Big switches which rearrange the battery pack into different voltage configurations to provide varying power to the motor. And those big switches are the part for the day.
I missed last night’s State of the Union Address, and this is actually pretty typical. I stopped listening to them because listening bothers and embarasses me on some level. Making no comments as to his actual intelligence or capability (this is certainly not the place for that), something about the way he talks seems to make even intelligent words sound poorly chosen.
Missing this one meant that I’ve gotten what I think is some pretty big news a day late. As part of his “Advanced Energy Initiative”, Bush announced a “22-percent increase in clean-energy research” including an increase in “our research in better batteries for hybrid and electric cars”.
We’ve finished tracing the flow of torque from the motor down a very simple path (skipping most of it actually; the driveshaft will have to be one of the last mechanical parts I get for the truck), and now we’ve made it to the wheel hubs. Today’s last cobblestone in that road is actually two parts, the axles.
I’ll be really happy when I get done with this heater, so I can put the dash back together and get on with the rest of the project. The phrase “dollar waiting on a dime” comes to mind. I did make some progress this weekend, and concluded most of the “fiddly” part of the process. The rest of the mounting procedure should be relatively straightforward from here.
Grasping defeat from the jaws of victory. We were so close.
With arguably the most sophisticated, successful and popular production electric vehicle ever made, that most of the country outside California and Arizona has only vaguely heard of (if at all), GM terminated their EV1 program, recalled the vehicles they had leased to the fury and dismay of their devoted customers, destroyed them at significant expense and lied to the public that there was no demand, fighting to discredit those who revealed the waiting list of thousands who never got their cars. And all this, just when the story was getting good, and the battery problems were finally being solved after a century of mediocrity. GM and the other manufacturers gave up, stopped the research, took their ball and went home.
Well, ok I made those two up. But today’s part does have a few names, depending on who you’re talking to. It’s typically called the center section, or third member. Often it’s called the pumpkin due to its similar dimensions, though this term is also used to refer to the entire visible bulge in the axle which contains the differential and gears, including that part of the axle housing.
(As inconsistent as all these names might seem, it’s not even close to the confusing lexicon of computers … ask any computer geek what the word filesystem means, and if you only get one answer, look elsewhere for information in the future.)
When planning the reworking of the truck’s mechanical features, I realized that increasing torque from the powerplant more than tenfold would necessitate a powertrain that’s a little more sturdy than stock. In reality the difference won’t be that severe at first, since while I’m increasing torque from the motor, I’m also ditching the transmission. If/when I do upgrade to a transmission later on however, I’d like the rest of the driveline to be ready for it.
Still even as-is, the motor by itself will be producing more than double the maximum torque of the original engine in first gear, and critically, will be capable of applying that torque instantly. We can’t expect the little stock rear end to handle that kind of shock, so today I’ll introduce to you the first part of its replacement.
Every major electrical system powered from a source capable of starting a fire should have fuses, right? Right. Electric vehicles are no exception. And while a more conservative EV might have a fuse with a barrel the size of a short stack of quarters, the ones I’ll be using are about the same diameter as a soda can.
This is a 700A, 500V Ferraz Shawmut fuse recommended by Cafe Electric for use with the high-voltage, high current system I’ll be running in the Ohmbre. It’s called a “semiconductor fuse” and the element carrying the current is encased in sand, within a fiberglass barrel about five millimeters thick. When a fuse like this blows the sand and fiberglass contain the fairly energetic explosion. Supposedly the sound it makes is something like a shotgun or a grenade. I haven’t heard it, and its an event I hope I never get to experience.
I guess this question is for the ladies (who am I kidding? … meh, whatever): Have you ever had one of those memorable moments when you’re walking along and you trip or stumble, your books scatter all around .. and then as you’re getting up there’s this stranger who stops and helps you, gathering up the pile of books and awkwardly handing them to you … one … at … a …time, and his eyes meet yours in a friendly, warmhearted gaze that makes you want to run and call the police?
Well today folks, I am that guy.