Sunday, February 17, 2013

It's alive!!!

That's right folks, I've brought life to my creation.  Today I actually drove my car!  Not very far, but it certainly moved on its own.  Here's how I got there.

I started Saturday morning and worked 14 hours until I didn't have any physical or brain power left.  By the end of the day Joe made the comment "yeah man, your mind is wasted."  I started the day by setting up more batteries to charge.  I got them all up to 3.41 volts, then strung them up in parallel so they could all top off exactly the same.  Here's my brother setting them all up.  Don't cross those wires, there's potential for 10's of thousands of amps here!

 It's also time to finish off the wiring.  Here I'm getting ready to make all the high voltage cables.  I've hooked up all the cable terminals where they need to go, and sheesh there's a lot of them!

And they're done!  Too bad there's a crucial error in here that I didn't realize until taking a last minute look at my schematic at 9 pm.  Luckily it's not a showstopper so I'll correct it when I pull the batteries again.

Here's the manual switch for the high voltage system.  When I flip this I'll get +230v to the controller through a precharge resistor.  When I turn the key, the B- contactor closes and completes the circuit to the controller and precharging starts (which takes about 1.5 seconds).  The B+ contactor closes when you first start to move the accelerator pedal, initially it does nothing.  In order to protect the controller and make sure it has a chance to precharge, you have to push a little red button on the dash that activates the switch hooked to the pedal.  Got it?  Okay, let's move on.

And here's the point where my mind started falling apart.  Joe showed up with his laptop and computer so we can test it out at high current.  Back over the Thanksgiving weekend we tested the controller at 80v and about 20 amps, but that's were we stopped.  There's basically no easy way to get higher current or voltage without hooking it up to a car.  It'd been so long I forgot how I we still had more to test on the controller.  At this point, Joe took out his phone to take a video of me starting it up for the first time.  I think his words were something along the lines of "If it works, we've got a great video of it.  If it's a spectacular failure, at least we'll have a cool video for all the effort!"  Luckily, "all" we heard when I hooked up power was the clack of the contactor closing.  After getting the motor to spin out of gear, we lifted the rear end, popped it in 4th, and spun up the tires.  Nice...

So that was Saturday.  Today I had a little tidying up to do before I was ready for a test drive.  All the cables were hanging out the bottom, a few things weren't screwed on very well, and I wanted to check over a few things I did in my frantic state the night before.

With everything in order I clear out all the tools, drop the hood, and hop in the car.  I start backing down the driveway (yeah!!!) and start turning so I can avoid running into my Jeep at the end of the driveway, and what??? why isn't the steering wheel turning???  I get to the end of the driveway and it feels like the steering column is locked.  I drive back up the driveway and shut everything off.  Ok, whew, it worked and nothing blew up.  But why the heck can't I steer?  Long story short, 7 months ago I made a major error that somehow didn't surface until this moment.  The motor mount bracket that cleverly snakes around the steering shaft isn't so clever after all.  If you turn if far enough, one of the clamping bolts on the shaft runs into the bracket.  Oh well, nothing that can't be overcome in and hour with a dremel, a die grinder, and a reciprocating saw.  I'll add that to the list of things to fix properly between now and taking it on a major road.

So back in the car, down the driveway, do a couple laps around the cul de sac, and it works!  I still have a bit to go to get it ready for the show, but overall I'm pretty happy.

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