GMC Clubmobile

During World War II the American Red Cross worked with the Army to modify about a 100 GMC CCKW trucks into the “Clubmobile”. These trucks were mobile units operated by the ARC, staffed with 3 volunteer women, and were designed to bring comfort, entertainment, and morale-boosting services to American troops stationed overseas. The program began in 1942 and became a hallmark of Red Cross efforts during the war. The Clubmobile Girls were recruited for their ability to connect with and uplift the spirits of soldiers.

The Clubmobile program remains an iconic example of wartime volunteerism, highlighting how small gestures—like a hot cup of coffee and a doughnut—could have a profound impact on the morale and well-being of soldiers during World War II. I’ve always been fascinated by the sociology of war. Away from the battlefield, away from the stories of heroic taking of a hill or saving of a foxhole buddy, there are so many things that go into maintaining an effective fighting force. And the Clubmobiles were an example of that.

I’ve been reading “Goodnight, Irene” as I’ve been working on this project and it’s interesting to see the impact on these volunteer women…and the impact of their work on the troops they encountered.

CAD Design

For this project, I’m designing the entire Clubmobile “box” (as I’m calling it) from scratch with Fusion 360. This has required a great deal of research since this vehicle isn’t documented very well. There are a decent (although surprisingly small) amount of exterior photos, but the interior photos are nearly non-existent. I’ve reached out to museums, restoration/reenactor folks, and searched for hours online to find good photos. I’ve found a few which has allowed me to move forward with some data and some assumptions.

Starting the CAD work: Exterior body design

Before we start talking about the CAD work, let me first share that this project has been on my project wishlist for years. A number of years back I picked up a CMK Clubmobile conversion set with the intention of building it straight from that conversion. In the years since then, my desire for Reasonable Accuracy has grown significantly and of course, I’ve learned CAD. I knew I had the CMK conversion set in my stash, but I also knew that however good it was, I’d want to spice it up.

When I finally got excited to get this project started a few months back, I popped open the CMK set… and discovered that the resin parts were warped as hell. My now-marginally-competent CAD brain said “Don’t worry about fixing this stuff, you can design your own!” So that’s what I did. I first started with the overall body shape.

I used the CMK kit as a basic set of dimensions and design ideas. This was a very helpful measurement fast foward, even if I ended up tweaking a bunch of dimensions to get things more accurate. In a little over a week of working a few hours a night, I had the basic body shape laid out.

As a side note: I used my Bambu P1S filament 3D printer to spit out a quick test model, just to be able to try it out on my GMC Conversion Mule (the old beat up 1/35 Tamiya CCKW model that I use to test my various GMC CCKW conversions). In about an hour, I had a tangible test model in hand to help me dial in the overall dimensions. Without any surface detail added yet, it was surprisingly pretty. And STRONG. I could have stood on this thing and probably not broken it.

Now was the time for the details. This is when the reference photos came in super handy. Given that there were ~100 of these made, I assumed they’d all be factory line consistent in how they were constructed. Mostly true, but some vehicles had some details, others didn’t. So I had to make some decisions. I also oversized the rivets a bit to give them some more obvious pop once painted. The restoration vehicles have much smaller ones than the ones in the historical photos. I think. It’s honestly hard to tell, so I am doing what feels right.

In a few more days, I had the various external details mostly done.

Then I went back to the Bambu to print a test model, mainly to see how good the tiny detail would turn out. Short answer: Not great. As amazed as I was by the smooth printing, I was really disappointed by the detailed test print version. I even swapped my .4mm nozzle for the .2mm nozzle and waited 22 hours for that version to print. It was better but nowhere near the quality of a resin print. So… resin for sure.

I ran another test print, this time in resin, to see if a box shape like this would actually print worth a damn. SUCCESS! It printed surprisingly well. Even if it just BARELY fit in my printer. This “barely fits the printer” has become a theme, so I was driven to order a large build plate printer. Hey, you do what you need to, right??

Time to switch to the design of the interior

With a solid amount of the external work done and the basic shape of The Box dialed in, I needed to switch to the interior. I needed to get a sense of where everything was and make sure it would fit… and that I didn’t need to make adjustments. For example, my roof detail work is way off so I need to fix it. But I can’t do that until I have the interior further along.

The interior reference material is TOUGH to find. I probably found less than a dozen helpful images of how the GMC Clubmobile (vs. the initial London Bus version) was laid out inside, or what each of the interior equipment/cabinetry elements actually looked like. I spent hours googling and generally figured out the elements of the interior. At least close enough. (I’m sure I’m going to stumble across a cache of great images as soon as I’m done with this project…)

Here’s an example of the London Bus layout

Once I had a sense of what I needed to create, I started laying out the various equipment/cabinets with post-it notes cut to “size” and used those to refine and layout all the things that sat on the floor. I created them each as dull boxes on the interior just to get the sizing and placement right. Once I had that dialed in, I started creating external files for each piece of equipment (like the donut fryer machine) and the cabinets. This will allow me to work on each one of those individually and just import into the main CAD file. I want to add a lot of detail to each element, so being able to work on them individually is much easier.