I was asked by Brian Bunger, the proprietor of one of the finest independent hobby shops in the USA (Scale Reproductions, Inc., Louisville, KY) to create a Cletrac M2 in 1:48; one for him and another for his brother who’s into 1:48 armor. At the time, I didn’t think there were any on the market, but after starting the design I did find a 3D printed resin version from a fellow in California in 1:35. I decided to continue working on it. The drawings were based on one profile drawing and a number of photos of existing units all on the Internet. Drawing took a while (weeks), and 3D printing on my Elegoo Mars original model took a while since many parts needed reprinting to get them right, but I am not very patient, but very, very persistent.
3D resin printing, while able to reproduce very fine details, has its limitations. Self-standing structures must have enough thickness to: a) stay intact while removing from machine and subsequent post-cleaning and b) be robust enough to have something left after the supports essential to the printing process are removed. For that reason, some of the details, e.g., the headlight guards, could not be made in scale thickness. Photo-etched would work better in this application. Regardless, the results are convincing and the client is very happy. I finished gluing up one yesterday and have one more to make.
Here’s an exploded view of the parts I had to draw in SketchUp. Each is a separated printed component. I did make one change. I was able to print the frame, winch and bumper as one part. The engine is a great little model in itself, but, alas, is very hard to see with the covers on.
And here’s the finished product…. still missing its fire extinguisher. I can’t make white decals that don’t have a colored background so Brian’s going to have to do that himself. Although if I could match the o.d., I could print them on white background decal paper with the o.d. background so you would have to cut out each tiny letter… just think’n.
Still have to add some glazing to the windshield.
It’s possible to print an entire model as one piece…. possible, but not practical. The supports needed to capture all the details would be overwhelming and their removal would destroy half the model in the process. Using a different kind of printer that doesn’t require supports would do the job. Laser machines using plastic powder do not need supporting like the liquid LCD Matrix resin machines do. But they are very expensive.
