Sunday, December 18, 2005

A Flock of Flywheels

With no reciprocating parts to cause vibration and plenty of mass in the rotating commutator, electric car motors need no flywheel to provide smooth power. However, if using a transmission and you want a clutch for smooth and speedy gearshifts, there must be a pressure plate and the associated hardware. Since every additional pound of rotating mass cuts into acceleration as much as almost 10 lbs of weight elsewhere on the vehicle, keeping flywheel weight to a minimum is important for optimal EV performance. A stock Type I VW flywheel, as shown below, weighs about 17 lb on my bathroom scale-o-riffic. After being attacked by a zealous machinist, that unwieldy piece of German chromoly steel came in under 7 pounds!

For additional perspective, let's look at the respective undersides. There's a lot of missing meat there, but none where it was needed! A note for safety- we're dealing here with an OEM German forged cromoly steel wheel here, not a cheap cast repro. Nothing less than the best can be lightened to such extremes and still be safely counted on to stay together under pressure.

Satisfied that my flywheel situation had been solved, albeit expensively (shaving this much steel consumed three lathe cutter heads, at machinist-by-the-hour pricing!), only then did I happen upon a unique EV goodie. The original Kaylor-kit is a 1970's piece of EV history; a cast aluminum adaptor plate that contains a bearing and splined shaft adaptor to mate a WWII era aircraft starter-generator to the VW transaxle. I previously spent over a year searching for one of these babies in hopes of getting started in the EV hobby cheaply, and also for the thrill of an old-school contactor-controlled conversion. I would've liked to learn along the same curve that the current gurus of the hobby did. HowEVer, the Kaylor plate proved difficult to find, and those that were offered for sale were prized a bit too preciously by their owners. Of course, once I turned down the modern path, I happened upon this never-used Kaylor Kit in the hands of a fellow VW owner who was only too happy to salvage a few bucks out of his orphaned antique project... And what did that Kaylor plate include, but a shaved-down VW flywheel! (Though this flywheel weighs in at an obese nine pounds, it's always nice to have a spare- until my next conversion!)

The last flywheel I'll mention was actually the first acquisition. This tidy piece of engineering is a Bob Batson (EV America) design, and it's innovative feature is a flywheel replacement built right into the adaptor. A simple steel disc is sandwiched between aluminum rings, providing for the lightest package of all, barely weighing 12 pounds, flywheel, hub, nuts and bolts and all (duct tape is holding the woodruff key and setscrews). The only weak spot in this approach is that it relies upon a pair of setscrews to keep the assembly centered and squeezed tight. This approach should work fine for a commuter conversion, but the "wisdom of the list" convinced me that one of Electro Automotive's bulletproof taperlock adaptor hubs was the way to go for smooth transfer of high power. Not only does the taperlock design ensure a perfectly centered, vibration-free assembly, but it guarantees not to be the weakest link.

The Electro Auto taperlock adaptor is deceptively simple, machined from a donor crankshaft. Mine arrived with a rather primitive appearance, as the cast-in oil journals were sliced through during machining, leaving rough pockmarks in the hub's surface. However, this wedgemated hunk of steel is certain to give the tightest connection practical between motor and flywheel.

Friday, December 16, 2005


(Note to Ghiaphiles, the nerf bars were NOT used for pulling, only to store loose chain!)
You see, Eleanor is the name given to the 1967 Karmann Ghia coupe owned during high school by good EV buddy and KG enthusiast Ross Olson. Rosso had acquired this fickle redhead at a bargain price, owning to the fact that nearly her entire underbelly was rusted out, though sturdily braced by a stolen street sign. The three short months that he had her on the road were adventurous ones. Shortly after acquisition, loose lugs let a wheel bounce off and accelerate past her on Interstate 5, never to be seen again. Not long after that narrow escape, she was shouldered off the road by a careless driver, and smacked right into a parked car. Ross escaped without permanent injury, but it was the end of the road for poor Eleanor. For the next 10+ years, she sat forlornly under a tree in Grant's Pass, collecting a fine coat of moss and mulch to accentuate her smashed driver's front quarter. However, that pristine red butt kept peeking out from under the fir to tempt passers-by.

This is how I met Eleanor, after agreeing to adopt her as a donor of parts, and also as a shell that will hopefully be transformed into a long range trailer for the Karmann Eclectric.
A what?!
Yes, in keeping with the thoroughly eclectic, some would say bass-ackward nature of this project, I intend to transform the rear of this crumpled relic into a trailer that will enable the Karmann Eclectric to venture far from home powered by an aircooled VW engine, just as the good Lord intended. HowEVer, the power will not be transmitted through a transaxle, but by beefy wires. I plan to build an aircooled VW generator set by coupling the engine to a consumer grade 10 kW generator head. More details to come in a future post, but suffice it to say that I've got plenteous ideas.
A long range trailer is not a new idea, it's been accomplished in several forms, from the elegant generator trailer by AC Propulsion, to the diesel drivetrain of Mr. Sharkey's decapitated Rabbit. My inpiration comes primarily from the first generation pusher built by JB Straubel.
Though it would be simpler and probably easier to rebuild Eleanor as a pusher rather than a generator trailer, I desire the additional utility that a generator will provide, such as trackside charging during NEDRA EVents. Also, in the event of a blackout, the Karmann Eclectric will be able to provide quite a bit of household power, but when he runs low, Eleanomore can kick in.

But wait, all this has been done before! Karmann Eclectric needs something unique. And besides, Eleanomore came in much better condition than I was expecting. It would be a shame to use just her rear when only a front quarter is damaged... Well, from college road trip experience, I know that a six-foot male can fully stretch out inside the cabin of a KG, so why not turn Eleanor into a Karmann Ghia teardrop camper? Okay, eclectric boy, now you're really going off the deep end. You're turning a classic econo-sportster into an eco-freak racecar, and now you intend to add a trailer hitch and take it camping? Truly wacko! Yes, this should be fun......

Back in Grant's Pass, we managed to extricate Eleanomore from her bed of needles, and load her onto the generously-loaned custom car trailer that usually sees service under the White Zombie or Blue Meanie. Thank you John Wayland!
Despite the best advance measurements that my tennis shoes could provide, the trailer turned out to be about an inch too narrow for the Karmann Ghia. We set the car on blocks in order to clear the fender wells, and then securely chained her down. As you may imagine, this complicated the manual loading of Eleanor onto the trailer, and the fact that she had one locked wheel and one missing wheel didn't help a bit. Never mind, the neighborhood provided a couple of gawkers who didn't hesitate to provide unsolicited advice, so we got 'er loaded in a jiffy. Ross's generous dad is a retired hardware store owner, so EVery time we needed another wooden block, length of chain, or a come-a-long, he burrowed into the basement and came up with whatever we wanted.

The road trip home was extremely scenic and otherwise uneventful, and after leaving the carcass out front for a day to pique my neighbors' concern, er I mean interest, I unloaded Eleanor by setting tall timbers as an elevated runway, tied Eleanor off to a sturdy post, and drug the trailer out from underneath. She now sits under cover in my driveway, awaiting her date with the Sawzall....

Monday, December 12, 2005

Plasma Boy's School of Charger Repair

Sorry it's been a while, but that's not for a lack of EV activity, but rather the opposite.
Last weekend saw the arrival of the new-to-me PFC 20 Battery Charger. The Manzanita Micro PFC line offers what's by far the most powerful onboard and versatile battery chargers ever obtainable by the hobbyist, and are completely user-adjustable with regards to input and output voltage, amperage, time on, and to some extent, charging profile. My charger comes secondhand from a fellow hobbyist who never could let go of his Bad Boy charger, concerned that charging by genset might fry the precious PFC. Well, the Manzanita Micro website gives clear instructions on how to determine if your genset is safe, and the Creator, Rich Rudman was willing to provide full support to me as second owner, so it's a risk I'm willing to take, err..., make. (More to come on manufactured risk in a later post.)

So, under the guise of retrieving my loaned video camera from EV Racer extraordinaire John Wayland, known in battery-safety circles as Plasma Boy, I head for Portland with the new charger under my wing. It had arrived accompanied by a strange rattling sound on the inside, and I wanted a semi-professional opinion before powering up the silicon. When I arrived at the Wayland estate, John was putting the finishing touches on some long-postponed shop cleanup, and looking for approval, he asked my opinion. My reply; of "It's lookin' pretty good, so is that corner over there where you shoved EVerything?" was appropriately appreciated....

While talking over some design decisions for the KarmannEclectric, we got into holiday topics. The associated commercialism and artificial niceties of this season have made Christmas one of Mr. Wayland's least favorite seasons, but determined to gain his wife's good graces, our hero enlisted my assistance in the hanging of gaily-colored lights from his roofline. EVer-attentive to tidy wiring, John had permanently positioned plastic clips long ago to ease this annual installation. Well, about half of these succomed to the weather, snapping off in our chilled fingers. Determined to prevent this recurrence, out came the self-tapping screws, and we installed enough wiring clips to make Underwriter's Laboratories proud. The lighting set was old, with large screw-in bulbs, and we had to make many replacements, juggling the bulbs from socket to socket in order to keep the colors in line (red, yellow, green, blue, purple, redyellowgreenbluepurple, red...), and creatively hiding a couple of dead sockets. At long last, the house was festively festooned, and just in time to tackle the loose charger before dinner.

We quickly opened up the case, and discovered that the sturdy copper inductor posts would have to be desoldered in order to remove the circuit board and access the problem point. Johnny-on-the-spot whipped out his gun and a clever little slurpee that removes molten solder via vacuum. Once the inductor posts were loose, we carefully pried the board free. The problem was easily rectified by simply sliding the shims back into position and firmly clamping the inductors, making sure to reset the locknuts. As we went to replace the board, I innocently asked, "What are those tiny hairs of wire for?". It turns out that we had overlooked the temperature sensor leads, and yanked four miniscule wires right out of their little homes. Not a user-repairable item, we'll have to call on the maker for more....

Now, there will be those who think it was unwise to bring my technical problems to someone who's motto is "We break things so you don't have to!". But heck, it was a great learning experience, and who knows, maybe an upgrade to the old PFC 20 will be in the works, now that it's already opened up and EVerything.........

To top off the evening, John's wife walks into the shop, as if on cue. She starts straight into some family business, ignoring the eager anticipation on her husband's face. Somewhat crestfallen, he asks- "Didn't you notice the lights?" She doesn't miss a beat. "Yeah Dummy, that's the old set you were supposed to throw out, where are the nice new ones that I got last year!"