Thursday, March 31, 2016

Gotta big new Green Box, but where should I stick it?

Ten years after getting my first Zilla (John Wayland's old Godzilla 1800, S/N 003), and then a Z1k, I've finally graduated to a Z2k for the Karmann Eclectric!  

Mounting this 2000 amp monster poses a quandary.  Do we saddle it directly to the 9" motor case?  My first controller endured some fairly violent clutch chatter before I got that all sorted out, and it died mysteriously while the car was tied down in a trailer, but with the telltale smell of popped capacitors.  Otmar had warned that extra vibration is something to avoid.   So- I seek consensus.  Is the eye candy of a color-matched controller riding atop its motor-mate with very short input cables worthwhile, or should the controller sit a foot away mounted vertically on the firewall, possibly even on rubber isolators for maximum vibration dampening?  In the past decade, many other motors have been ridden by their controllers- any regrets out there?  The other option is to mount it to the firewall, where there's plenty of space and probably enough structure to support that 24 lb chunk of copper.  

Thursday, March 17, 2016

Sylvester Lives!

On this sunniest and warmest day yet of 2016, we made the final wiring connections, and after a couple of minor hiccups, Sylvester took his first drive on Lithium with Zilla Power!
Only for a few blocks, as the pack needs to be recharged and there remains a lot of wiring clean-up and adjustments to be done, but we DIDN'T BLOW ANYTHING UP.

Must be just a little luck o' the Irish in there, if I don't say so myself.

And it just so happened that I found a couple other ice cream trucks to park next to too!
(Yes, generic white trucklets in front of generic white houselets, Sumner really is more interesting that it looks!)

Thursday, March 10, 2016

A month is a long time

So, we have much progress to report on the Grumman Kurbwatt!
Installation of the following components has been accomplished.

  • Manzanita Micro PFC-20 battery charger with J1772 compatibility upgrade, along with an external dc-rated input circuit breaker and output fusing that bypasses the 'Run' contactor.  
  • Zilla 1k motor controller, coolant pump, radiator, reservoir, and fan.
  • 53 amp 13.8 Volt output DC-DC converter and 'house battery' using a spare Valence XP-27
  • Two Kilovac contactors, one for "Run" and one for safety.
  • A Gigavac manual disconnect, essentially a rotary version of their vacuum-sealed contactors
  • An LED dome light with red "night vision" auxiliary function.
We re-energized the 12V system yesterday to re-verify function of all original components and begin the commissioning of the 12V control and instrumentation wiring.  

After that comes the first high-voltage tests; first of the charging system and then propulsion.  Having a rear-mounted pack with a rear disconnect has been a blessing, in that we can work freely without any high voltage present in the motor bay.  

Thursday, February 11, 2016

Batteries Are In and Baby Got Bling (just some new shoes).

We kept it simple and put a single string of ten modules in the tray for, 120 V nominal and 15.6 kWh of capacity.

There's a couple of awkward-looking long jumpers in there, but it was the only layout that placed most positive and most negative at the back of the pack without placing any modules on edge.  
The rearmost compartment has one battery in it in this photo as a counterweight, but that cavity will remain empty for Phase 1.  It may be used when a second string of modules is added.  This shot was taken while filling the gaps with foam insulation board.  

After cabling up the battery pack, freshening up the Anderson disconnects and re-mounting them with stainless hardware (yes, the corrosion risk is tiny compared to the old flooded pack, but I don't like rust!), we turned our attention to the outside.  

Through creative dealmaking, I wound up with a couple of parts cars: a 1985 Nissan Pulsar converted by Dave Cloud in 1996, which the last owner had never gotten around to modernizing, so we're reusing the Valence battery pack that never got installed, along with the battery charger and a few other components to reuse on this project, and the motor, etc. for others.  

That car also came with some very shiny aluminum wheels that were good as new and period-appropriate for the Grumman.  Besides- everybody knows that little Japanese cars use a 4x100 lug bolt pattern, right?  Confident in that fact, I mounted new LRR tires and brought my prize to the student mechanics.    
Time for another lesson.  The Pulsar had 4x4.5" lug spacing, aka 4x113.4mm.  So no fit.  There's room in the solid centers to re-drill the 4x100 pattern, but machine shops willing to take on that work are rare, and I found a set of billet adaptors for less than redrilling should cost.  
The adaptors add 1" of track to each side, but the front tires still fit within the wheelwells and there's no chance of rubbing, even at full suspension travel.  In the rear, the sidewall bulge is barely wider than the body, but there won't be any rubbing either, due to the generous wheel openings.  All the tread is inside the wheelwell, but some fender flares might be in order down the line.  I'm not worried about extra stress on the spindles from a wider stance, as this battery pack is 484 pounds lighter than the original one, and even adding a second string will be 40 lbs less than original, and more evenly distributed.  Lastly this van was designed to carry a full load of mail in addition to the lead-acid batteries, so there will be durability to spare.  

Lastly these new wheels brought our attention to a bit of camber, probably because the suspension is riding higher to the tune of 484 lbs.  It's not bad, so I'll wait for the weight of a second string before adjusting the ride height.  And of course, if this project wraps up well, the kids would love to airbag Sylvester!  

Thursday, January 28, 2016

Stuffing is the hardest part

After rebuilding the Grumman battery tray rollers with technical help from the capable countermen at Motion Industries, we discovered that though the tray could hold 14 batteries with a few rows set on end, two of those rows would just barely interfere with a floor beam, and the cabling gets difficult any time you set batteries on end.  Also, the manufacturer may allow it, but they're never quite as comfortable with any installation where the batteries don't sit on their base as designed.
That and other factors is pushing us towards a simpler pack layout with ten in the main tray, and ten in the forward body cavities.  Those two parallel strings at 120V nominal will still provide over 30 kWh of capacity, yet be a very safe voltage for student mechanics to work with.

BUT, when adult entertainment is desired, a simple switch could unite the two strings in a series circuit of 240V for higher performance.

Also in the interest of speed and simplicity, I'm leaning towards getting the van rolling with a single 10-battery pack to start off with, and then add more once the bugs are worked out of EVerything else.  placing batteries is tough work, especially when safety is job one!

The charging inlet has been changed from a jury-rigged industrial plug that was placing 12 VDC on two pins and 144 VDC on the other two, all in close-proximity exposed blades, to the modern J1772 standard.  The original inlet mounting plate was reused, so of course a billet aluminum inlet was used to match!

Tuesday, January 19, 2016

Stuffing the KurbWatt

The original Grumman battery tray will hold 11 Group 27 batteries after removing some of the center partitions Yes, that weakens it somewhat, but in the long and strong direction, but we reinforced the floor and have reduced battery weight by over one third.  We've also found another battery donor, one of the few local users of Valence batteries, for a total of 24 U-Charge XP27 batteries available, which adds up to 39.9 kWh!   This would give the truck a 39.9 kWh pack weighing only 1056 lbs.

 Three batteries will fit in an unused body cavities ahead of the rear wheels on the passenger side, but only two behind the driver due to cable routing.  The seat platforms are nice boxes that will also hold two batteries apiece.

 Add up to five batteries in the motor compartment, and the count stands at 24.   That should be good for up to 200 miles at low speed around town, or no less than 114 miles on the highway!

Battery placement is still being decided, and we may use fewer batteries to KISS, but we also have two Valence U-Charge BMS systems, each originally set up for 12 batteries.  Running two packs in parallel would extract the maximum energy at minimum stress, while operating at safer voltages (144V nominal rather than 288V).  Power delivered by the controller would be greater at 288V, because then the motor could be fed with 170V, which the maximum voltage for decent brush life, and not sag below that 170V during high current (1000 amp) accelerations.  That 170 kW would be 240 instantaneous horsepower, probably more than the Rabbit clutch could tolerate!

144V or EVen 132V is our likely course since students are involved, but it leaves an option open for putting the sub-packs in series when daddy goes to the track!

Tuesday, January 05, 2016

The Grumman Gets Gutted...

Though we were able to get the Grumman Kurbwatt running in very short order, it was due for an all-around update, so as soon as all systems were go and the brakes were road-tested, it was time to take the electric parts apart.

The battery pack is being replaced with donated set of used first generation Valence U-Charge Lithium Ion modules, which match the outgoing Group 27 lead acid batteries.  Our plans are to replace the controller with a Zilla 1k, and the Lester "boat anchor" battery charger with a Manzanita Micro PFC20, complete with full J1772 interoperability for public charging stations.

The Valence cells are probably a half-measure, being of uncertain capacity and remaining life, but will enable extensive road testing and tuning of all the other upgrades before building the ultimate battery pack.

Sure enough, once we managed to pull the control board (with the controller, main contactor and auxiliary relays mounted) it became apparent that there were about twice as many wires as necessary, and every time we opened up a bundle of electrical tape, we found either an ugly splice or abandoned, dead-end wires.  Plan A is to use a multi-pin Amphenol connector to have a single disconnect point on the new board for all small-gauge wiring, enabling easy removal of the board, along with a couple of Anderson connectors for the big stuff.

Charge On!

Monday, November 23, 2015

Solar Washington, Part Deux.

Why should a solar installation be a one-time thing, and why would one have one 2160 Watt Array, when you could compare it to another 2160 watts of of solar right next door, but using different technology in a different manner?
Our 2015 project involved assembling 400 square feet of solar atop a sturdy steel frame, once again courtesy of Boeing Surplus Sales.  The clearspan structure was built from thirteen 20' sticks of SuperStrut steel channel, literally a big boy's erector set!  There's no substitute to vastly overbuilt when it comes to amateur engineering, as each of those sticks could support 5000 lbs!

The modules came from electric vehicle co-conspirator Matt Moreno, who has limited area with solar exposure on his home, and decided to upgrade from these Kaneka 60 Watt thin film modules to the Iteks that dominate our Made in Washington market.  These thin film modules are sometimes superior in our low light conditions, and the panel has complete coverage with active material between the frames, with no gaps as appear on mono or poly crystalline modules.  Thin film can outproduce crystalline during diffuse, indirect or the low-angle sunlight that we often have here in the cloudy northwest.  However, in terms of annual production per square foot, crystals are where its at.  So, I got 32 of these at depreciated and friendly pricing, plus found six more new-old stock modules to square out the array and stock two spares from a depressed "Prepper" who never put them into use (which doesn't matter much because the world didn't end after all).

In order to not be too obtrusive on the neighbors and to maximize my covered storage space, (at the cost of  8% less annual production than optimal tilt of 34 degrees). I set this array at the minimum 6 degree angle required for drainage, and came up with a mounting method that made the roof rain-tight using continuous strips of aluminum to bridge the longitudinal gaps, and the steel channel frame catches rain from the horizontal gaps and channels it to either side.  Like any simple shed, there is still dewfall below, but it is an improvement over sun and direct rain.  Note that optimal tilt does not equal latitude here in the cloudy PNW.  Most of our insolation comes during summer, so optimal tilt is biased towards summer production.

It was a nice bit of luck (that I pushed, of course) to get two arrays of the same rating; 2160 Watts from 36 Kanekas and 2160 Watts from the 8 Iteks!  But wait, there's only one inverter, isn't there?  Well, to maximize the state incentive scheme, I'm switching the Iteks over to Made in Washington Blue Frog microinverters, which apply maximum power point tracking to each single module in the array while producing grid-tied 240 VAC at the array.  Normally this would be overkill on a dual-axis tracker, but my modules do see some shade in the early mornings and late afternoons, so this will squeeze a few more electrons out of it.  This approach also fits into the theme of comparing technologies, and it will be interesting to watch the performance under different conditions and over different timeframes, as well testing as the long-term reliability of each.  This will also allow reuse of both the AC and DC wires already passing under the lawn, without expensive rewiring.

Solar Washington

It is often feared and now well-shown that electric vehicles are a gateway to other subversive activities, such as a drive towards energy independence.  With that in mind, I started solarizing the Donnaway homestead last year.  Never one to choose the simple solution or pay retail, I found an orphan, the overbuilt WattSun 1200 dual-axis solar tracker, which was discontinued after a corporate takeover, but I can hardly blame them, as the falling price of panels no longer justifies the added cost of a mid-size tracker.  It's usually cheaper now to get more production with more fixed-position panels than to point them properly at all times.

This tracker was an orphan because the original owner accidentally encroached on his property line with it, which was discovered during a pre-sale survey.  So, I got a bargain and learned the technology through manual dis-assembly and reassembly.  Part of the deal were 18 12-Volt nominal panels, which I saved for an off-grid application and replaced those 1835 Watts worth with 2160 Watts of Made in Washington Itek 270 Watt modules.  These eight panels will pay off better due to the state incentive structure.  Construction didn't commence until mid-summer, and final electrical inspection was accomplished on 12/28/2014, just in time to cement my tax credit!

PapaJoe Donnaway assisted in the engineering as we set sixteen feet of 8" steel pipe into a six foot borehole, six feet deep and six feet across.  The pipe was good galvanized Schedule 80, but a Boeing Surplus bargain, having spent its first 20 years as a parking stop..

We poured a whole pallet worth of concrete mix, applied in the following lifts:
First, a 6" floor with rebar threaded through the pipe base, topped by 2' of  native gravel and cement mix, then another 6" of  rebar and concrete, topped with another 2' of  "localcrete" and another slab, then topped off with the cobblestones that I had dug out of the hole, for a natural but weed-resistant and heavy base.

In addition to two wiring conduits that I trenched in at a good 36" below the back yard, I ran a 1" water pipe to a frostproof hydrant n order to have both water and power on the far side of the yard, and all the way back to the spa house.  Kind of a long round trip, but the water doesn't care.
Like many summertime construction projects, I kinda pushed the schedule on this one, and was working on it right up till the end of the year...

Tuesday, November 17, 2015

Sylvester Signs a Sponsor!  

Longtime friend and fellow eCo-Conspirator Tracy Farwell has seen fit to invest substantially in Sylvester's rehabilitation through his Better Energy, LLC. enterprise.   Better Energy seeks to bring about change in light and medium-duty truck fleets by repowering mid-life delivery trucks with proven battery-electric drivetrains.  Most EV conversion efforts have been short-lived due to their pursuit of extremely expensive AC drivetrains and their attendant complexity.  Better Energy believes that a simple series-motored BEV is the key to maximized economic utilization, and a far more attractive equation when paired with a local delivery truck that may not do many miles per day, but delivers lousy mpg, noisy and noxious onsite impacts, and is maintenance-intensive.  A battery-electric truck with a modern lithium-ion battery pack and a basic drivetrain make a powerful and affordable combination.

The classic Grumman Kurbwatt with an upgraded battery pack will demonstrate this concept at the small end of the scale, while John Lussmyer's electric 4WD Ford F-250 MegaCab Longbed amply demonstrates this concept in a very popular package.

Thank You Tracy!

Introducing Sylvester

As a result of my EVangelism and attempts to mentor EV newbies in the local area, I received the donation of a very special vehicle; a pristine 1983 Grumman Kurbwatt postal truck, one of only fifty built.
Here's the story if its creation, courtesy of

The Electric KurbWatt and Gasoline/Diesel KubVan were the United States Postal Service's answer to the 1970's Oil Crisis. The Electric KurbWatt and Gasoline/Diesel KubVan were designed to save the United States Postal Service 500,000 gallons of fuel per year. The Electric KurbWatt and Gasoline/Diesel KubVan were ready for mass production, and was being tested by the USPS by 1983. The KurbWatt, and the KubVan were to replace the converted army jeeps that were used to deliver the mail door to door. The KurbWatt and the KubVan have the same mail delivery capabilities as an army jeep, but would save the USPS 500,000 gallons of fuel per year. The Electric KurbWatt, and the Diesel/Gasoline KubVan are the only vehicle to pass all of the USPS endurance tests. The KurbWatt and the KubVan were not mass produced because they were determined to be too small. The USPS needed a vehicle in a hurry, so Grumman designed the Long Life Vehicle (LLV). The LLV was larger, but got the same fuel economy as an army jeep. No fuel was saved.

Somehow, one of these wound up in the Washington State Dept of Transportation Fleet, where it was well-cared for and received an upgraded GE motor, larger than the original 7" Prestolite, as well as an upgrade to 156 Volts and a compatible Curtis controller!  A nice handwritten note from the WSDOT mechanic accompanied this trucklet into private hands at the surplus sale.  After two private owners, the Grumman was sitting in the weeds with a dead house battery and unknown other concerns when offered to me.  Thankfully, it turns out there were few other concerns, as the traction battery pack still had some life in it, being a bunch of Deka Dominators that were salvaged from a crashed Solectria Force.

It took one day to resurrect the Grumman and give some test drives, winning school district consent for the idea of training high school auto shop students in EV basics.  Sylvester, as we'll call him, has a five speed 1983 VW Rabbit front end, and a VW Dasher (Passat, Audi Fox, Audi 80) rear axle.

First order of business is making sure the binders are good, so off came all the wheels, and as usual, removal of the rear brake drum cylinders  resulted in a rounded-off brake line nut and we had to replace the hard line.  This was an excellent educational activity that will certainly result in safer stopping!

Lets Meet Tweety

After years of preaching the EV gospel at work, which had already resulted in the installation of three public charging stations and my boss buying a plug-in hybrid Ford C-Max, I succeeded in convincing Sumner School District to add an electric vehicle to its operations.  We settled on an EZ-GO burden carrier from Boeing Surplus.  I had been watching for a while, and scooped up a bargain that had lived life indoors and had a fairly fresh battery pack, in addition to a newly-replaced motor.
The name just seemed to fit, given that tiny body and big ol yellow head.
Tweety's no lightweight, however.  With 360 lbs of lead-acid batteries under the bed, a heater and fan in his head, a one-ton carrying capacity and 6-ton towing capacity, he came ready for work.

However, the intended mission didn't work out.  Seems that our district mechanics, after years of driving a sickly gas golf cart, wanted something more macho, claiming that they couldn't fit inside, and a diesel Kubota 4x4 would be much better suited for the job of topping off fluids and jump-starting school buses.  Never mind that burly Boeing machinists had used this cart for the past 22 years, and it is a twin to what hauls injured NFL players around!  Ever one to rise to the challenge, our 7 foot tall Director of Athletics folded his size fourteens up against the go-pedal, and said "Guys, this would be great for the Stadium- can we take it?!"  All parties breathed a sigh of relief, and Tweety now hauls ice and trash and tows sweepers and rakes to groom turf in far greater comfort, style, and cleanliness than the old diesel gator that he replaced.   And the mechanics?  They got another gas golf cart without a cab...  Just Sayin'

Thursday, August 13, 2015

Now it's on!

After increasing frustrations with my flooded nicad pack, I'm finally making the upgrade to Lithium!  As sadly happens often in this hobby, one project died that another might live.  I purchased a full inventory of conversion components from the widow of a gentleman who obsessively ordered parts for his planned Corvair conversion while in a cancer ward, but he never made it back into the garage.  Most of the components are now energizing a brand new conversion by a first-timer who needed a good buy, but the battery cells remained with me, and have been rounded up from 38 to 60 cells with matching inventory from good 'ol Don Blazer of Portland OR, who has organized many group buys over the last decade.

So, out come the nicads, destined for second lives in other projects, and in goes 19.8 kWh worth of lithium that should be more reliable and live through more cycles than any OEM vehicle.  That's saying something, because I've been very impressed with the pack management in my Mitsubishi i-MiEV, which shows no measurable degradation after 42,000 miles in two years of driving (three years after manufacture, as this car sat on the dealer lot for a full year before I purchased), and between it and the first i-MiEV, I'm at over 65,000 i-miles.

Back to the transplant.  I expect improved performance, which had been stuck at a 16.8 second, 81 mph quarter mile due to severe voltage sag in my nicad pack.  Range should also improve from 30 miles on a prayer with the 7.2 kWh of nicads to a confident 80 miles with the lighter weight 19.8 kWh pack of CALBs.  My 62 mile-rated Mitsu is capable of over 80 miles of sedate driving on local roads in summer from its 16 kWh pack, and in back-to-back tests, the Karmann Eclectric has delivered the same 200 Watt-hrs per mile efficiency when driven on the same route in the same manner (and that was on big sticky performance tires!).
Prior to putting the cells into the car, a 'bottom balance' was executed, which consists of placing the cells in parallel, for a 6000 amp-hour, 3.2 Volt pack, and deeply discharging them, then recharging while still connected in parallel.  That ensures an equal start on life.

Here's the front pack layout, 2x11 cells.

And here's one of the two rear subpacks, each holding 19 cells.  It always amazes me how much work it takes to figure out how to fit stuff in there in a matter that looks obvious in the end...

Monday, June 16, 2014

Is this thing on?

I just noticed that the Google overlords have actually updated some of the blogger features, and am just running a quick test.  Neglect of the user interface has made insterting new photos on Blogspot difficult for some time.  The Karmann Eclectric is currently undergoing a battery rebuild, but the end is near.  I've reinstalled four of the five original subpacks.  The fifth, which was behind the driver's seat, is being eliminated because it prevented full seat travel, was most at risk of a short circuit, and allowed driver weight to imbalance the car (which rarely carries a passenger).  I've cleaned the cells and hardware, beefed up the hold-downs, and configured the cells into buddy pairs, effectively giving 60 amp/hr cells rather than 30 ah.  I'm also adding 48 cells in the rear compartment to offset those lost from behind the driver's seat, and these are being contained in aircraft battery boxes for greater safety and serviceability at the expense of some added weight.
This pack rebuild came about because Karmann Eclectric was selected as a beta tester for J1772-enabled charging from Manzanita Micro!  This means that our classic EV will be able to hook up to the newfangled 'idiot-proof' public charging stations without any adaptors, switches, or twiddling of knobs!  Manzanita is giving some new guts to ye olde PFC20 while I install the new vehicle inlet and rejigger the cabling...
The first version didn't quite work with most public charging stations, but I've just received version 2 from Manzanita, and am eager to get back on the road!

Thursday, January 17, 2013

Tow a what with who?

An astute observer may notice that all of my vehicles get hitched.  That's right, though I believe in plural vehicular marriage, all of these vessels should be capable of carrying more than their fair share.
Sometimes, a hitch might be retasked for something other than traditional trailer towing.  Load platforms are one excellent example,

bicycle carriers are another;

and the previously mentioned pusher trailers are another.  Of course, pusher trailers don't have to be petroleum-powered.  For some designs, chicken nuggets will do just fine.

Sometimes, there really is a trailer that needs relocating, and it's just the tow rig that needs substitution.

And you thought I was joking?  After all, my buddy needed the Burley, and it's very cold and foggy tonight! 

With such capabilities, who could blame an EV for copping a little attitude?

Thursday, August 23, 2012

Gearing up for Friday

Stephen Johnsen created this fine design for Friday's little get-together.  No great expectations, as I know that Karmann Eclectric's battery pack is the weakest link, but I haven't had a timed run on record with the motor wired in parallel.  I've also picked up a pair of 205/75R15 tires, which will add 6.7% to the tire circumference, and requires 50 fewer revolutions to the mile (or 12 fewer to the quarter-mile).  At a minimum, it should improve trap speed from 78 to 83 mph.  If we get into the 14 second range, it'll prove a rousing success. 
Last item before the race is trying to add a remote to the differential locker, as it's a pain to keep crawling under the car to reposition that pin! 

Update: It's apparent that the batteries are doing all they can, and tinkering with the other pieces is doing little to nothing.  HowEVer, the car ran reliably and consistently, with all four runs within 0.5 mph and 0.4 seconds.  79.9 mph and 16 seconds is where she'll be until new batteries can be installed.

Saturday, August 04, 2012

Gettin Rangy

When recently EV-aluating my lengthy list of projects and want-lists, it suddenly became apparent that only one would offer maximal benefit to both the Karmann Eclectric and the iMiEV for minimal cost and risk.  Most EVery EV'er would want to have his range and eat up the track too, but those are usually exclusive attributes.  For me to build a battery or genset-based range extension trailer for the Mitsubishi would involve serious hacking of OEM systems and a near guarantee of a voided warranty.  The genset trailer has already been proven on Karmann Eclectric, but EVen at a steady 3KW into the pack, it only adds a max of 10-12 miles of range to any single trip.  HowEVer, a pusher trailer would give nearly unlimited highway range to the Karmann, and could also operate behind the iMiEV with the factory controls none the wiser!  When being pushed, the i should simply think that it's on a downslope, and allow coasting or regen, whichEVer I command.  In order to make the pusher easily transferrable between vehicles, I plan for wireless accelerator control via an aftermarked cruise control by Rostra that also features vacuum-free electric throttle actuation...
For safety's sake, I'll use one hardwired switch in each vehicle to enable/disable the ignition.
So for those of you who haven't followed this SEVEN YEAR dream, the basic idea is to use an aircooled VW drivetrain to push the EV down the highway, with very simple controls that will leave the tranny in 4th gear and clutch depressed until one is at highway speed, and then energize the ignition and dump the clutch, which will make the pusher roar to life, with remote throttle control.  For safety, one can kill the ignition at any time, adding full engine braking to the vehicle and trailer's service brakes...  Otherwise, when taking an off ramp, one would throttle down the engine, energize a linear actuator that disengages the clutch, and then shut down the engine in a civilized manner...

I'd been hesitant to hack up a Ghia pan to launch this experiment, even though the donor car was terminal, because it would be difficult to do without looking like a hack, and probably have more tongue weight than desired.  Then it struck me that a Type III VW (Notchback) rear subframe was made for the job.  The thing even already includes a tongue that gracefully finishes off the wishbone which holds the engine and tranny.  Now I can add a trailer coupler in place of the original rubber front body mount, possibly even without welding...(or just use a pintle hook).
Has a subframe ever been nominated for a beauty prize?
And of course, my favorite parts scrounger from the Samba, ProjectVW would have one a a great price! 

Thursday, April 12, 2012

Staying planted required triangulation, and can lead to Gettin Hitched!

I've meant to add some detail on the mighty fine truss bar set that was provided by Lanner Khan of V-Dub Engineering.  It was a complicated job that involved a lot of trimming and fitting to weld four mounting tabs to the wishbone thta holds the tranny and motor, and four more tabs to the upper shock mounts.  This was made possible by the welding skills of Roger Wright, along with the loan of a wire feed welder from Good Neighbor Tom. 

The five truss bars were installed in the spring of 2010, but the rear end was not finally finished until the trailer hitch took shape in the summer of 2011.  A TRAILER HITCH, you say?   Why of course.  Who would waste such colossal torque on a subcompact commuter that has only modest drag-racing ambitions without also ensuring that one can also tow a boat, a boatload of extra batteries for range extension, or even another half a ghia
So, since the Gene Berg bus-to-bug transaxle adaptor was already over-beefed, that was a logical mounting point, and since the original front transaxle mount was no longer in use, that made for a nice forward mount.  Most trailer hitch receivers add at least 25 lbs of dead weight to the car when not in use, even without a ball mount, so I wanted to eliminate that penalty.  The final solution was to drill a couple of holes through the beefiest point on the tranny mount, and pin on a step-bumper-styler 2" receiver that had been modified with a couple of angle iron brackets on top.  Then I passed a 5' piece of 2" square tubing forward and inserted it into a "duckbill" bracket that prevents both horizontal and vertical torque on the rear mount, but still lets the rear mount handle all of the pushin and pullin....  take a moment on that...

Friday, March 30, 2012

The more things change, the more they stay the same.

So after wishing I could throw in the towel on this bb600 pack aftermultiple incidents of spewage, ground and interpack shorts that melted holes through a dozen cells, and apparent loss of capacity down to about 16 Ah, Karmann Eclectric didn't get a lot of use after a fall recommissioning of the pack, but I cycled it a few times over the winter, took a few short drives, and got the Onan range extending genset trailer working, due largely to a lack of confidence in the pack. The car seemed to be sulking, especially when I added a 2012 Mitsubishi iMiEV to the fleet! Well, it seems that the pack was actually ready for prime time once again! Tonight, with a pack temp of 50 deg and outside temps a few degrees lower, I topped off the charge and took the car for a diciplined 45 minute drive, covering a 27 mile loop with only 4 stops at intersections, for an average speed of 34.8 mph and a peak speed of 68 mph (climbed up and coasted down a 127 foot incline twice at speed, with many other smaller climbs). The 200 cell pack came off a peak charge of 333V and rested at 305V after about 15 minutes, with 0.1 Ah of parasitic consumption before takeoff. I set off with headlights blazing and pulled into the garage 45 minutes and 27 miles later, having consumed a total of 31.1 Ah, or 6.82 kwh. That's 1.148 Ah per mile, or at an estimated average V of 230, a battery-to-wheels efficiency figure of 264 Wh per mile. Next time I'll reset the EMeter to report kWh instead of Ah, and then it'll be time for some data collection with the range trailer hooked up!

Not bad, considering that this was at night in a car with a very heavy-duty transaxle and series motor, while my iMiEV consumed 257 Wh/mile during a 51 mile conservative daytime drive (though it's the current king of regen, that trip was mostly highway). Hey, guess it's time to hit the road again and drive that same loop in the i!

Back on the road, and the iMiEV made the same run in the same time with apparent consumption from the pack of 7 kwh. Sorry, the guessometer doesn't get any more accurate than the nearest kwh per bar on the graph. That would match the Ghia's performanceof 6.82 apparent kwh. (I minimized regen by shifting into neutral and coasting or braking as required to better match the Ghia driving style.)

So Mitsu, whassup with that? You produce the most efficient vehicle ever rated by EPA, and it's no better or maybe EVen a bit worse than a homebuilt drag racer cobbled together out of surplus and rebuilt castoffs and a heavy truck tranny? Time for more tests and better instrumentation!

Tuesday, March 27, 2012

To Make a Jelly Bean Fly.....

The iMiEV may look smooth, but with a Cd of 0.35,  it ain't exactly streamlined.  That round rear is not optimized for aerodynamic drag, and the slotted wheels aren't necessary when there's such little braking heat to dissipate, due to strong regenerative braking.  So, the DIY community has long cooked up little modifications like salt flat discs, fender skirts, air dams, belly pans, duckbills, rear visors, and even boat tails!  Here's a rendering of what some of those mods might look like on an i.  Here's also a link to a Dutchman who made the best DIY removeable boattail that I've seen. 
This quickie drawing shows what an iMiEV might look like with disc wheel covers, rear fender skirts, and two different options on the rear.  In black, I echoed the rear passenger window profile.  This could be done nicely in black lexan, and be semi-permanently affixed to the hatch.  A sharp rear edge would make better aero, but for the sake of buildability and artistic license, I chose a curve. 

In grey is the outline of a possible Kammback boat tail.  For you sailors, you'll recognize the concept of 'waterlining'.  Stretch out the same or even a bit more mass into a longer, more streamlined shape, and you'll reduce drag.  This one follows the rear body curves as closely as practical without actually touching, and has a sharp rear cutoff as dictated by good old Mr. Kamm

Here's a graphic of one of the few spoilers scientifically designed for drag reduction rather than downforce.  Too bad they're not commercially produced.  Time to start whittling!

And the Texas Mile winner in October 2011 chose a simple duckbill for drag reduction rather than a downforce spoiler.  If a high po Corvette doesn't lift at 245 mph, d'y'all rice boys really think that a wing's gonna help your Civic

So, the easiest among the above winners would be to simply add discs to the rims.  I went a notch up from JC Whitney's offering, but not quit Mooneyes pricing, and got the Taiwanese-made CCi brand, and am very pleased with the heavy gauge metal (yeah, adds a bit of rotating mass but doesn't dent when I push 'em on), excellent finishing, and positive lock on the wheel..  Still don't know how difficult they will be to remove, but I've got the right nylon pry tools. 
I'm thinkin it looks EVen better at night.

Thursday, February 23, 2012

Ever wonder why they don't make gasless donuts?


What you can't see in the vid is the gleeful face of my passenger; a mom from Ruthie's 5th birthday party who after hearing a burnout on the last demo drive said, "Yeah sure, let'er rip!"
But this one was sorta loose, as I didn't even engage the locker. That's for when you wanna pirouette on the front axle! ;-p

Service- my i!

All proper homebuilt EV's have some manner of emergency disconnect that the driver can use to mechanically disconnect the battery pack for either emergent or prudent purposes, such as when servicing the car. Not so with the OEM EV. My i has a 'service plug' to interrupt the high voltage system, but it resides in cramped quarters below the driver's seat, beneath a wing-nutted metal cover.

Not something one can easily access when the pedal sticks at highway speed! (at least our cars have one failsafe in the EVent of 'unintended acceleration'- you only have to avoid obstacles for 20-30 minutes at speed before the car runs out of juice!)

Being undeterred by the multilingual warning label, I removed the safety disconnect's safety cover.
Below here, one operates more on feel than sight, pulling forward the orange lever and lifting up the plug.

The insert has two not-oversized pins for the traction power, and two little signal pins that probably carry 12V. It snaps back in position as easily as it comes out, and the car comes back to life, memories intact.
Happy Motoring!