1942 Willys MB (Jeep) (Pinewood Derby Shell)

Summary

Full 3D View

The 1942 Willys MB is one of the most iconic military vehicles of World War II, often recognized as the original "jeep." Designed for rugged terrain and versatility, it was a lightweight 4x4 utility vehicle used extensively by the U.S. and Allied forces. Its simple, durable design made it ideal for reconnaissance, transport, and even battlefield communication. The Willys MB became a symbol of American ingenuity and mobility, and its legacy lives on in the modern Jeep brand.

During WWII, approximately 640,000 Willys MB and Ford GPW jeeps were produced. Willys-Overland built around 363,000, while Ford manufactured about 277,000 under license. 

What is a "pinewood derby car shell"?

The 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. You can either use the printed model or use it to accurately cut an official wood block down to size.

Please note:

• This pinewood derby car shell is not the full allowed length of 7". Including the bumper and spare tire, it is about 6.25". That reduced length could affect racing speed (although this model wasn't designed for speed, anyway).
• The wheelbase of this car is 0.5" shorter than the standard, so, if you plan to use the wood block that comes with the official kit, you will need to drill axle holes or cut a new axle slot.
• The wheels and tires that come with this model are NOT suited for racing, and are provided only for showing off the Jeep. You will need to use the wheels that come with the official kit for racing.

Print Settings

Notes:

• Car body: I printed the body of this vehicle at a 30 degree angle, as in the profile I created and uploaded. By printing it at an angle, the layer lines were reduced to the point that they're barely noticeable if you print it using a matte PLA OR if you paint it with a matte paint. I used Rust-Oleum Deep Forest Green camouflage paint.
• Some parts are really small, and may be best printed using a 0.2mm extruder. I did all parts with a 0.4mm extruder.

Post-Printing

Just super glue all the parts together.

Smoothing

By using matte paint, I didn't have to smooth the body, but I could have gotten it a lot smoother using 3D printing resin and baby powder. 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.

Weights

You can add tungsten weights to the holes in the rear of the body to end up right at 5 oz. There is only room for 1.5 oz. of tungsten weights in the holes behind the rear axle, so you may need to print with more infill to get to the full 5 oz., or add more weight. (You can fit some behind the back seat.)

Patreon/Commercial License

I just do this for fun BUT if you insist on throwing a couple of bucks my way or if you'd like to sell prints of any of my designs, see my Patreon page.