Friday, March 13, 2015

One Step Forward, Two Steps Back

First the good news:

Last post I showed the EV West interference fit coupler for the Siemens motor. It arrived this week and I took it over to Pro Automotive for Robert Juarez to have a look at it. We discussed grinding the rivets off of the clutch disk and using the center section to mate with the splines on the drive shaft. Keith pointed out that if we bolt the clutch center section directly to the flange of the coupler, we effectively eliminate the spring effect, so why not attach the spline directly? 


Given that the coupler from the Siemens motor to the E-Gear drive on the Transit Connect is a straight splined tube with no shock absorbing capability, why not?


















On the left you see that Robert has removed the spline from the old clutch disk and fashioned a round mounting plate from sheet steel. On the right is the spline in position on the mounting plate. Welding the spline to the plate will be  stronger than the press fit in the original clutch. Dave, the machinist next door, will drill and tap the plate and coupler to make sure that everything is precisely centered, trued, and balanced. So work on the coupler is moving along nicely. Once we are able to mount the motor, we can get on with fitting everything under the hood.


Now the bad news:

VERY SIGNIFICANT GOOF BY ME!

I had mounted a chain to one of the batty pack modules to get it off the workbench in preparation for Robert to pick it up and take it to the shop to install in the Porsche. That was fine until last night my wife was bringing in groceries and knocked it off and it shorted the exposed terminals on the front. I know better than to use a metal chain, but as Hillary Clinton said "it was a matter of convenience."

The good news is no explosion or fire, but lots of sparks as the chain welded itself to some of the terminals. It looks like it's pretty much toast.

The plan is to insulate the remaining exposed terminals, pry or cut off the welded chain links, and assess the damage. With any luck, some of the batteries will be usable. Fingers crossed!

It looks like these batteries are available from a couple of sources, so all is not lost. It will drive the cost up, but at this point I'm too far in to let that get in the way. Chalk it up to expensive lesson learned.



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