Tow Truck

Conventional Tow Truck

I created one of these for the Men At Work diorama. I started with the GHQ Ford tow truck kit, and built it per the instructions. Then I started over. First, I created a ski rack, but before that, I opened up the filled-in space under the roll-over bar. Next, I added front and back parking lights, plus work lights mounted under the corners of the roll-over bar. Finally, I scratchbuilt a totally different lift, as the one that came with the kit was quite uninteresting. Using reference images, I modeled an integrated tow rig, a.k.a. lifter-wrecker. It includes a wheel-lift*, plus a wrecking boom, outriggers and a variety of other accessories. Mine is admittedly on the chunky side, but given there are hundreds of different variations, I'm not too concerned. (I think it would make an excellent accessory for 3D printing, by the way.)

The model will be positioned on the diorama with the visually interesting "business end" facing front, which has the added benefit of hiding the model's solid windows, as well as the lower half of the bulky ski rack. As for the animation, it's a simple crank mechanism. The mail truck only moves up and down a small fraction of an inch, but the large gear was necessary to achieve the properly slow travel time. It has no indexing, which means the user must hold the button down until it reaches the desired height.

A C-shaped spring steel wire mounted at the mail truck's rear axle keeps the truck in place: it pulls down and pushes forward at the same time. Meanwhile, the rod that lifts the mail truck has a tiny hook at the top that fits into a relief just behind the mail truck's radiator; the forward push from the spring keeps the chassis engaged on the hook. This makes it easy to remove the mail truck, if necessary (I wish the same could be said of all of the other vehicles on the diorama!).

As for finishing touches, the tow truck sports a yellow ski rack, and the mail truck has a set of four-ways that includes a green dashboard blinker, just visible through the door window. Originally the tow truck was going to get four-way flashers as well, but I thought that two sets of four-ways, plus the ski rack, would be too much blinky-blinky. The ski rack can be seen working in the video:

*Wheel lifts are very common these days, but I chose a frame lift style instead for a very particular reason: I'd already animated the tow truck with its original sling gear. This picks up the vehicle by the front of the frame, leaving the front wheels dangling. When lifting the vehicle, there's a subtle effect that takes place: the front suspension goes slack, which means the front wheels rise up after a short delay as the body is raised; then, when lowering, the body keeps lowering for a bit after the wheels have already touched down. This does not happen with a wheel lift. I went through some trouble to reproduce this effect, and really wanted to keep it, so my tow truck has a frame lift, even though the rig is styled like a wheel lift. Only tow truck operators would spot the difference.

In order to create the slack suspension effect for the mail truck, I had to extract the front axle from the chassis using a jeweler's saw. Since the axle was cast into the chassis, this was tedious and slow-going, but worth it. Once free, I reattached the front axle by slipping a short segment of fine brass tubing onto a piece of fine steel music wire, then bending the wire roughly into an inverted V-shape. Then I bonded the free ends of the wire to the front axle, and the tube to the chassis. The final step was adding a retainer strip; see the image below left. Gravity is sufficient to drop the front wheels as the tow truck raises the front end of the mail truck; see photos below right.

Cosmetic work was done on 27 July 2022. This also included a complete rebuild of the overly-bulky and poorly-designed lift gear on the tow truck. Note that the view below is not "normal"; the normal viewing angle is square-on from the back of the mail truck, so things like the wires under the tow truck and the lift pin under the front of the mail truck would be out of sight. 30 July 2022 marked the day the tow truck was permanently grafted to the side of Spano's Service Station and installed on the diorama.

Flatbed Tow Truck

We've all seen those flatbed tow trucks picking up disabled cars, so why not model one? I've wanted to, but haven't had the opportunity yet, and may not have the time left to try. It would be one of those background animations that runs every so often, or on demand, as opposed to continuously.

Depending on your level of ambition, the animation could range from just the flatbed tipping up and down to a full cycle of the car moving onto the flatbed before it tips into place. A linear drive would likely do the job.

Of course, the process would have to be reversed, but that's not necessarily undesirable.

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