The Bradley GT II Electric was equipped with a defroster but not a heater. The defroster unit was positioned under the dashboard in a fiberglass plenum that was integral with the firewall and molded into the body of the car. Fresh air was drawn by a fan thru a hole in the forward face of the plenum (the car’s firewall), was warmed by a set of three resistance coils and was ducted to a pair of outlets on the top of the car’s glare shield. One relay controlled power to the blower motor and a second relay controlled power to the heating coils. Switches on the instrument panel controlled the relays.
When I received my car, several modifications had been made to the system. The air inlet hole in the firewall had been blocked off with, of all things, a round amber lens from a school bus’ turn signal. Hey — it was the right size! A smaller inlet hole was drilled into the plenum on the passenger-side of the firewall, reducing the fresh air feed from outside the car. Two trapezoidal holes were cut into the plenum cover. You can see these in the photos above. Adding these holes had the effect of recirculating cabin air thru the defroster. Presumably, the cabin air would have been warmer, making the defroster more effective. There were no valves or dampers in the system, so the relative amounts of recirculated and fresh air were determined simply by the sizes of the holes thru which the air flowed.
The outlet side of the system was also altered. One of the outlets in the plenum chamber cover was ducted to both defroster outlets with hoses and a tee fitting. The other outlet in the plenum chamber cover had a small louvre. This had the effect of directing some of the air from the defroster down towards the driver’s feet. Again, there were no dampers in the system but by closing the defroster vents, all of the air would have been directed towards the floor of the car under the instrument panel. The modifications were really quite clever and probably aided in improving the comfort of the occuppants.
The photos show how the whole thing was assembled. I’m toying with the idea of adding a few further modifications. I’d like to put dampers on the trapezoidal holes. I’d also like to re-open the original hole thru the firewall and add a damper there. Finally, the smaller hole thru the firewall — the one added by a previous builder — would be sealed off. This would have the effect of controlling the relative mix of inside and outside air — similar to what you find in most production cars. I don’t know if I can do this, but I’m going to start thinking about it.
It’s been a while since my last entry, so I figured I’d better at least make an attempt to update the journal. Most of the last few weeks have been spent painting and cleaning parts. I made a decision a few weeks ago to powdercoat those parts which will be exposed to road grime and the weather, and to paint parts that wouldn’t be exposed to too much grime. The painting job is done except for the front beam assembly. I want to spend a day removing welding spatter from the front beam assembly before I paint it (and from the rear diagonal arms, before they’re powder coated). All of the parts that need to be powdercoated have been sorted out, media-blasted and are just awaiting the funds to do so.
For the past few weeks, I’ve been standing in front of a wire wheel, de-rusting nuts, bolts, washers, screws and all of the small miscellaneous parts that go into making a car. It’s amazing how many there are. If I had a spare $300, I could buy a vibratory tumbler and get the job done in a day — but then I’d have to figure out where to store the darn thing untl the next job came along. So, I’m just doing it the old fashioned way. I made the mistake of backing into the rotating stone on the other side of the grinder’s motor two days ago and discovered that it doesn’t take long for a stone rotating at around 8000 RPM to take a chunk of your elbow’s skin off. Ouch. That’ll leave a mark!
I’ve also set aside a group of parts that will need to be buffed and polished. These include things like door hinges, aluminum moulding strips, key latches, “Bradley” badges, etc. Once all of the hardware has been de-rusted, buffing out parts will be the next job.
In the meantime, I received the new seat sliders a few days ago. The old ones had rusted tight and couldn’t be disassembled because of the way they were constructed. By having the sliders available, I’ll be able to incorporate mounting structures into the sub-chassis instead of just bolting them to the floor pans as the previous builder had done. Mounting the fiberglass seat buckets to the sliders will require the fabrication of some custom mounts and I suspect that that’ll be a job coming up shortly. The seat pans apparently had at least two previous sets of sliders mounted to them and, as a result, they have a lot of unnecessary holes in them. Patching them up will be a job that comes up in the near future.
I took the roll bar (T-Top support) to a racing shop a week or so ago and asked them to weld on a pair of 1/2-13 nuts to act as mounting points for a pair of shoulder harnesses. The original Bradeys didn’t have shoulder harnesses. They suggested a different approach as they were concerned that welded nuts might not hold in an acccident. Instead, they drilled and mounted a pair of 1/2-inch high-strength steel bolts thru the roll bar from the back side (outside) of the roll bar. This is probably a better approach, although I’m not sure that I like the pair of 1/2-inch holes that had to be drilled thru the bar on each side. Seems to me like the welded nuts might have been better.
It hit 108 yesterday here in Las Vegas. That will pretty much kill a landscaping project that I’ve been working on in our back yard until September or October. It’ll also give me the opportunity to work inside on the Bradley a bit more. Oh, the advantages of having an air-conditoned garage…
Work continues, in sort of a hodge-podge fashion. I spent yesterday sorting thru all of the metal parts that came with the Bradley kit car — things like bumper brackets, the accessory battery tray, the T-top post brackets, the roll bar (if you can call it that), seat slider brackets, etc. — and sorting them into piles. One pile is going to the sandblaster (these parts will get painted), one is for the powder coater and one pile needs to be sandblasted, inspected and modified before I cart them off for powder coating. One of the modifications that I want to perform is to weld a pair of 3/8- or 1/2-inch nuts to the insides of the vertical portions of the roll bar — to act as anchor points for shoulder harnesses. There were also a bunch of VW parts that got sorted into these piles — things like the steering column, spring plates, diagonal arms, bearing retainers, brake backing plates, etc… Once the sorting was done, I carted off the first category (75 parts in all) to the sandblaster.
I’ve also been sanding a lot of the smaller fiberglass parts — mostly to get the old upholstery glue off them and to prepare them for making fiberglass repairs. The sanding literally made my fingers raw. 40-grit will do that! To reward myself, I spent two days digging a ditch in the back yard for a new landscaping project — a stone-lined dry wash. Digging with a pick shovel doesn’t seem to bother raw fingertips but it sure is good exercise.
I’ve also been working out a preliminary wiring diagram for the car and a preliminary design for the instrument panel. Some of my background is in designing wiring systems for experimental aircraft. As a result, I’ve decided to wire my car more like an airplane than a car. There won’t be any fuses — instead, I’m going to install a breaker panel with Tyco pull-type circuit breakers that I’ll obtain from Aircraft Spruce & Specialty. The Motor Volts and Speedometer gages will be moved off the gauge panel and will be placed on either side of the steering column. I’m used to having the speedometer in front of the steering wheel and I want to change the design of the instrumentation to permit that. Additional indicator lights will be added to verify that the motor blower is functioning and to indicate an overtemperature condition on the traction motor. The motor has a built-in over-temp sensor — might as well put it to good use. The heater blower switch will be split into a fan (only) switch and a heater switch, with both switches relocated to the main portion of the dashboard. In addition, I’m going to add a battery master switch and battery solenoid for the accessory battery — similar to the one you find in general aviation aircraft. This allows me to disconnect the accessory battery from everything, in case of an electrical problem. A new Accessory Battery Ammeter and Voltmeter will be added to the gauge panel as will a Pak Tracker battery condition monitor.
Once the design is finalized, I’ll fabricate the dashboard and gauge panel out of 1/8-inch aluminum, paint them flat black and then silk-screen them with the appropriate labeling. The original gauge panel was made from some sort of phenolic-like material and it warped badly under the summer heat. I’m also toying with the idea of fabricating a small overhead console out of fiberglass and aluminum. At a minimum, I want to put two reading lights up there. If I need additional space for low-current switches, that’ll be the place where they get added.
Over the next few days, I’m going to start refurbishing all of the nuts, bolts and other hardware that came with the Bradley kit. The VW hardware is finished at this point. I’m shooting for about one more month to finish the chassis and then I can begin the redesign of the sub-chassis and battery boxes.
I’m now two months into the project, and the only unresolved concern is still the rubber parts (gaskets, seals, weatherstripping, etc.) — especialy for the sliding windows in the doors. Virtually none of the rubber that came with this car is salvageable.
Over the last few days, I’ve been working on a variety of small projects. First off, I picked up the traction motor from the local rebuilder. The owner checked everything out and powered up the motor to demonstrate it for me. It ran like a charm — no bad noises. The brushes and bearings are good and there is no problem with the wiring — even after havimg sat out in the Las Vegas summer heat for 15 years. In the next few days, I’ll disassemble it so that I can have the case media blasted and powder coated.
I’ve also been studying the electrical diagrams for the car, in anticipation of designing a new instrument panel. I need to understand how the car is wired before I can decide how many switches, circuit breakers, instruments, etc. I want to put on the panel.
I got stuck when I was reviewing the circuit for the headlight motor. I had assumed (in error, as it turns out) that some kind of reversing circuit was needed to raise and lower the headlight buckets. It turns out that the reversing is actually accompliahed by the mechanical linkage between the motor and the buckets’ torque tube. The motor actually runs in one direction only.
To figure this out, I needed to disassemble the motor to see how it works. So, I figured that I might as well rebuild it at the same time. It turned out to be a good thing that I did. The motor is mounted under the left side of the hood, right near the gap between the left side of the hood and the car body. There wan’t much of an attempt to keep water from leaking between this joint in the body panels and, as a result, the interior of the headlight motor had some pretty bad rusting. It took a while with a Dremel and a wire brush to clean up the inside of the motor. Also, one of the springs that keeps pressure on one of the carbon brushes had rusted in half. Luckily, I had another that was similar in size in my Hell Box.
My motor has two wires — a red one and a green one. It doesn’t have the black, black, red and green ones indicated on the car’s wiring diagram. After a bit of experimenting with a battery charger (used as a 12-volt power supply), I determined that the motor needs to be powered between the green wire and ground. One of the motor’s brushes is grounded inside the motor’s case. Powering the motor between the red wire and ground makes it run at a faster rate, so the red wire is not used. Powering the motor between the red and green wires (not using the ground connection) makes it run erratically. The motor also has an internal limit switch in the gear head which is not used.
At 12 VDC, the motor draws about 0.61 amps and runs at about 25 RPM. This seems a bit fast to me. A 180-degree rotation of the output shaft on the motor’s gear box is enough to raise (or lower) the headlight buckets. That puts the actuation time at just over one second. Granted, my speed test was with the motor unloaded. Once the motor is connected to the linkages, it will probably turn somewhat slower. Still, it looks like the headlights pop up and down pretty fast.
I also spent some time painting some of the smaller chassis parts yesterday (grease caps, U-bolts for the sub-chassis, washer plates for the CV joints, etc. The nice thing about living in Las Vegas is that the summer sun (it was over 105 degrees yestrday) gives a nice baked enamel finish to any parts that you paint outside.