Saturday, January 30, 2010

Hey Karmann, why the long fates?

2009 was quite a year for Karmanns of all stripes. The grandaddy of them all, Karmann Gmbh in Germany filed for bankruptcy shortly after it's US spinoff, Karmann USA began offering a stupendous service to restore their classic cabriolet tops. Fortunately, VW came to Karmann's rescue in some small sense, by buying up the company's bones and announcing their intent to produce cars in the Karmann plant in 2011. The Ghost Dancer is lusting for a redo by Karmann Classics, as it's most recent top saw the summer out with a bang- that is, the header bow completely cracked apart at one corner, meaning that raising or lowering the top is now a very tender and time-consuming process, only to be done once or twice per season until major surgery is affordable...

But you didn't come her for any of this- what about the ELECTRIC CAR!

Karmann Eclectric had an interesting summer of road-testing, with several near-misses and valuable lessons learned. After the first few drives, significant slack had developed in the accelerator cable, so I tightened it up, making sure that it would return all the way back to open the 'dead pedal' microswitch. Confident that the upper range of available power was now available, I dialed the Zilla controller all the way up to 500 amps and was preparing for a run when my good-natured and quite conversational hot-rod-building, recently-retired neighbor ambled over. Tom was really missing being behind the wheel of a hot car after experiencing some recent vision problems, so I invited him into the passenger seat for this test run.
Well, the shifter was a bit balky, and I could only get it into reverse, so I thought no problem,I'll just bump it back a bit to shake things loose and then shift into forward. Well, when I did so, the car LURCHED backwards, driving my foot deeper into it, and both rear wheels immediately lost traction and made smoke as we rocketed towards the rear wall of my garage with the controller STUCK FULL ON. Within milliseconds, my reflex was to hit the brakes and pull the handbrake, bending a 45 degree angle into the handle! Still that didn't stop the car, and the front wheels added another foot of black streak to my shiny floor. As hope began to fade, since my silly neurons had yet to reach the right hand with a TURN OFF THE KEY message, the car rolled over my floor jack, and as it forced the handle down, the high-ratio racing jack lifted one corner of the car just enough to unload a wheel and let the differential dump into thin air. I then managed to shut 'er down, and after Tom confirmed that his heart had resumed production, we inspected the car. Other than a knocked-over tool chest and a socket set that had been spewed forth by my spinning wheel as silver confetti, the only damage was a small scratch on the rear flank where Karmann Eclectric barely brushed my workbench. Talk about a close call (and proof that I need a garage door in that section of wall after-all)!
Turns out that I didn't have enough return spring pressure to reliably bring the potbox from the brink, and perhaps some stray sandblast or other gunk in the cable race added just enough friction to keep it far forward when I released the go pedal... Well, the cable race has been blown and lubed, and a much tighter spring is now holding back the potbox lever! This is not a mistake to repeat. Here's a couple of shots showing the miraculously minor consequences..