1957 Maserati 250F (Pinewood Derby Car Shell)

Summary

Full 3D View

The Maserati 250F was a Formula One racing car that won several races in 1954 and 1956, and then won four World Championship Grand Prix in 1957, as well as 4 non-championship races.

The blueprint I used for this car was really bad, so the model isn't very accurate. Also, I chose to use the standard Pinewood Derby wheelbase, which is quite a bit longer than the real car (which means that the front and rear of the car don't extend beyond the wheels as much as they should), so that it would qualify for races where the standard wheelbase is required. But I think it looks nice, anyway, so hopefully some people will like it.

BONUS: The car is pictured with show wheels and tires, not legal for racing. Models are included (under Raw Model Files) for the show wheels and tires, in case you'd like to use them. (The larger tires obviously are intended for the rear.)

What is a "pinewood derby car shell"?

A pinewood derby is an event created by the Boy Scouts many years ago. Each scout is given a pinewood derby kit typically consisting of a block of wood with slots for axles, 4 wheels, and 4 nails to be used as axles. The scout (and his dad, usually) will then carve the block of wood into the shape of a car, paint it and apply stickers, install the wheels on the axles, and then race it at the "derby", which involves a sloped track with a timekeeping apparatus.

An official scout derby will usually require that the parts in the kit be used for cars entered in the derby. Other organizations (including workplaces) often hold derbies, too, and some of them require the use of the parts in the box, including the block of wood.

These "pinewood derby car shells" are intended to be used with an official derby wood block, cut down to size, along with the axles and wheels included in the kit. A printable model of the shaped wood block is provided (under Raw Model Files). You can either use the printed model or use it to accurately cut an official wood block down to size.

Printing

• Body: Requires normal supports on the build plate only. This is a VERY light model, so you may need to use a very high (60%+) fill to bring the weight up high enough to hit 5 ounces, even with tungsten weights. (You can always add weights under the car to hit the 5 oz. limit.)
• Mirrors and exhaust are pretty easy to print with normal supports.
• The gas cap, windshield and steering wheel are easiest to print with brims.

Post-Printing

Assemble the car using super glue. The seat and windshield are very difficult to get aligned, unfortunately, but I couldn't get the look I was after any other way.

Smoothing

You can find videos and guides online that describe the process, but here it is in a nutshell:

• Mix 1 part resin and 2-3 parts baby powder in an opaque container (so that it can be stored without hardening due to UV exposure).
• Using a paintbrush or cotton swab, spread a thin layer of the resin/baby powder mix over the body, wherever you want to smooth print lines and gaps.
• Use a UV flashlight (a cheap one--like the kind used to harden resin finger nail polish, which you can order from Amazon or buy in the pharmacy department of Walmart) to harden the resin.
• Sand the body smooth until there are no thick layers left.
• Repeat over any areas that are still rough.

Other Notes

You can add tungsten weights to the hole in the rear of the body. If you plan well, and use enough infill, you can maximize the weights and end up right at 5 oz.