Friday, May 1, 2015

Palm to Forehead

Sometimes we make assumptions that get in the way. In planning for the motor and inverter mounts, I'd always had the cable junction box on the top of the motor. That's the way every product photo shows it. That's the way it was strapped to its pallet as shipped from the factory and the way every other build I had seen using this motor was positioned. It made for some challenges in fitting the inverter and especially in getting the cables on the DMOC 645 to reach all the way to their connection. I'd seen the inverter mounted on its side on the firewall and crosswise over the motor, usually to avoid the extra height of the terminal box. We'd considered mounting it vertically in front of the motor but rejected that idea because the short cable wouldn't reach.

This week I stumbled across this photo of the entire driveline as it was designed and installed in the Ford Transit Connect.

DUH!!! Palm smacks forehead. This thing was designed to have the motor rotated 90 degrees so the junction box is on the side and the cables are sized to route neatly to their terminals. Who'd 'a thunk it!

I knew Robert was working on motor and inverter mounts so I dashed over to Pro Automotive with this photo. Happily Robert hadn't committed welder to steel yet, so we could rethink this without scrapping a bunch of work. Turns out that rotating the motor 90 degrees right interfered with the steering box, but 90 degrees to the left found some open space near the motor mount. Here's what it looks like in that position:

The cables will lose their symmetry but will still reach. The inverter is sitting on a block of wood for test fit, but it can be lowered at the front if need be for hood clearance. I'm pleased with this arrangement.

At the other end of the car, Jack Rickard has said that 80 percent of a build effort is getting the batteries to fit. After that it goes pretty quickly. Robert fabricated a tray for the eight pack of batteries I brought over earlier in the week.

The sheet metal between the seat back and the battery box was a bit flimsy for the weight of the pack, so Robert moved the tray to the rear so it is fully supported by the battery box which is resting on the hefty box section frame supports. It's sitting a bit tall, so the legs will be cut down so it just clears the lower pack. It will leave about two feet of deck space, perfect for stowing my instruments as I head around town for rehearsals and concerts.

There is access to the lower pack terminals through the opening between the tray supports. Once these connections are made, it looks like a perfect location for a small box to contain the charging controller and its associated relays and connections.

The final four pack has been assembled to fit vertically in the space next to the maintenance disconnect, so the battery pack is pretty much complete. It's all in one place, which is convenient, but there is some concern about fore/aft weight balance. I'm remembering the steering situation with the eBugeye and prepared for the fact that I may need to add some ballast to even things out. Visually, the ride height doesn't appear to be too low in the back even though the front is completely empty at this point. There are ways to adjust the ride height by reindexing the torsion bars or adding coil-over shocks, but we'll have to wait until we have everything installed to do that final tuning.

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