Friday, May 14, 2010

May 7th Show Now Online

We've made some recent progress on the Speedster Part Duh, and rather gotten ahead of ourselves on the video thing. We were trying some things, they came together, and we're not too much wanting to remove them at this point. So in this video we kind of do a walkaround to show the week's progress.










Brian installs our Chennic charger in the front of the car. Very neat assembly.

We decided to mount the charge receptacle, a Marinco NEMA 5-15 recessed male, where the torsion bar access port is on the drivers side. This looks good and is very easy to access, though down low. If you are going to get in the car and drive it, you pretty much have to stumble over the power cord to do so, which should prevent the situation of driving away with the cord connected.

Brian installed the AC-50 motor in about 15 minutes. He simply put it on a jack, jacked it into position, and it slide into the transmission. Four bolts and it was over. Looks great. Not much to report.

I've been working on some secret sauce. I've been fascinated with carbon fiber and kevlar hybrid resin materials. I love these little carbon fiber body parts you can get. They look great and they seem quite strong but very very light. I wish we could get the Speedster fiberglass body in carbon fiber of course.

In any event, we had a huge problem with Speedster part UNO. It was supposed to use 160Ah cells. We wound up with two strings of 90AH which actually gave us more range in some ways. But the reason was that we got beat by about a 3/2nd of an inch on our battery box in the engine compartment. The motor winds up being a little over an inch off center from the frame. And on the right side, we couldn't get our box in after building it.

In Speedster part DUH, we have a little thing going on. The AC-50 just isn't quite as big in diameter as a Netgain Warp 9. That gives us some room. As you saw in the April 30 show, we did some things different with the adapter plate as well to gain some more room.

I've been playing with carbon fiber/kevlar hybrid cloth and some very slow cure 2:1 epoxy resin. Basically, we built a smooth aluminum box to the precise dimensions I wanted to hold 10 Sky Energy 180AH cells. This includes a cutout around the engine adapter and transmission brace.

We then waxed the box with form release wax three times, and then painted it with PVA - a liquid form release agent.

I then gave it a good thick coat of this remarkably thin slow set epoxy. We let it dry until it was more sticky than wet, and layered a layer of 5 oz carbon fiber square weave over it.

We then started layering kevlar/fiberglass hybrid cloth. This stuff is so stuff we couldn't cut it. Finally bought a pricey set of dress designers shears and it cut it VERY nicely. We would layer on a layer of fabric, and then "stipple it" with the thin epoxy using a cheap paint brush. We added about 3 layers of that, and wove in a couple of flat aluminum pieces in between layers. We'll use those to screw into the car frame.

When we got done, we disassembled the aluminum box underneath, and we were left with a carbon fiber/kevlar eggshell of a battery box.

The result is incredibly light - about 3 pounds. It holds 126 pounds of batteries very nicely. It's chemical resistant. It's non-conductive. It has some fascinating thermal characteristics. And it is THIN.

We're going to do one for the left side. But I think I'm going to try styrofoam block for the form. Acetone dissolves it, and it should be easier to remove than the aluminum box.


We also started installing parts of the Curtis 1238 controller cooling system. We mounted a fill bottle, the heat sink, and the pump.

Enjoy

Jack Rickard

2 comments:

  1. Jack,
    Saw the video and your battery box reminded me of my experiments with Carbon / Kevlar hybrid cloths back in College. I found that no matter how sharp my scissors were, the Kevlar eventually destroyed them. I finally found some scissors with Ceramic blades that held up and didn't shred the fabric.

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  2. Shorter range with regen: This is contrary to my experience with 2000 Th!nk City. I think the reason in your case is that you change your driving style. A more aggressive driving style wastes more energy than regenerative braking can recover.

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