In the Great War, America found itself with a muscular heavy equipment manufacturing industry that could have readily produced tanks; but it had no tank designs. The US ended up building licensed copies of the French FT-17 light tank, and the Mark VIII “International” heavy tank as the war ended. After the war, the US began experimenting with tank designs of its own. Walter Christie was a talented and experienced automotive engineer. He submitted designs and working prototypes of tanks to the US Army throughout the interwar period. In WW1, tanks were viewed as armored, self-propelled siege-engines for breaking through the trench lines at which point their job was done. They were slow, the speed of a walking infantryman, and mechanically unreliable. Christie’s 1921 prototype had a two-man crew, was small, turretless, armed with a 57mm gun and two .30 caliber machine guns. It was fast – 13 mph (20.9km/h). Christie solved the problem of getting slow, unreliable tanks to the battlefield by removing the tracks, storing them on the fenders, and running on the road wheels over improved roads. The downside of the Christie suspension design was its very rough ride. The US Army Ordnance Department requested that Christie improve the suspension system. Although only a single prototype was built, it laid the groundwork for future high-speed tanks.
Vargas Scale Models from California USA produces a nice mix of interesting and unique subjects from World War One and the Interwar periods in1:35th scale. All are CAD designs and 3D printed in resin. This is a one-of-kind subject – there is no other kit in any medium or scale of the 1921Christie.
The kit is packaged in a small sturdy corrugated cardboard flip top box. Inside are the instructions, and zip-lock bags with 14 3D printed resin parts cushioned in bubble wrap. The instructions are three pages printed in color. They consist of CAD renderings with circles and arrows to highlight the assembly. Text is in English only. There is no parts list or painting instructions. No decals or photo-etched parts are included or needed. No painting instructions are included. Period photos show a dark, assumed to be Olive Drab, vehicle with no markings.
This kit shows off the capabilities of 3D printing. The 3D printing process allows a surprising amount of detail to be represented on a single large part that might require dozens of parts if molded in styrene or cast in resin. The hull is printed as a single piece. The running gear and tracks are a single piece – no road wheels to clean or individual link tracks to labor over. The front suspension includes fully functioning coil springs. The fenders are thin and delicate.
3D printing does introduce a couple of new steps in the build process. To ensure that the resin is fully cured, lay out the parts in direct sunlight for several hours. The parts require thorough cleaning with a toothbrush in hot soapy water to remove any residue from the printing process. Some of the parts exhibit 3D print striations. These should be carefully sanded out. I use a desktop HEPA air cleaner to control the dust while sanding. A KN-95 mask would also work to avoid breathing in the resin sanding dust. Once the parts are cleaned up, the assembly is trivial using CA glue. The parts fit is good. The instructions are minimal but adequate. Dry fit everything and then use cyanoacrylate to glue it together. Use a sandable primer for the 3D printed parts. This helps the modeler in finding and removing the last of the 3D print striations. I have had good luck using Mr. Color 1500Black Primer in a rattle can.
This is a unique subject – no other kit is available in any medium or scale. CAD design and 3D printing are starting to fulfill their promise of making affordable kits of obscure subjects a reality. Vargas Scale Models is at the forefront of this revolution. The kit builds into a good replica out of the box. It is more appropriate for experienced modelers due to the sanding and use of CA glue. I highly recommend the kit and hope to see many more kits of obscure WW1 and Interwar subjects from Vargas. Vargas offers their kits for sale on eBay at vargasscalemodels