Wednesday 21 September 2022

Demag CC 2800-1 Blog update

Prototype perfection

In one of our previous blogs, we had a look at all our different builds and configurations. Most of these setups are tested in 3D design, in combination with hardware parts and previous constructed models, to calculate the strengths, weights and angles necessary for our ambitious CC 2800-1 project. But 3D only gets us so far. Today we will be looking at the other three major design stages, starting with the 3D printed prototype.


3D printed prototype


Modern 3D printing allows us for rapid prototyping of all parts into physical objects that we can touch, assemble, and inspect. While such an early prototype is not a true representation of die-cast metal connections and strengths, it does allow for visual comments and function design. Testing whether you can connect the crawlers without turning your hand in impossible angles, for example, is difficult to assess on a 3D model. This is where our printed prototype comes in.

Another example for its use is testing all hardware parts, such as the reeving of rope, nuts and bolts, cylinders, and photo-etch inlays. Hardware parts are pieces that are not shaped in our own molds, but are aquired by our purchasing department. The 3D printed prototype is a ‘live’ sample, meaning that we update it with every feedback round until we are satisfied. After a final check, we start with shaping our die-cast molds to form our first metal sample.


Metal sample

After several weeks of cutting shapes for our die-cast and plastic molds, we run a first ‘test-shot’. This is the first time we pour liquid metal in our molds to shape our ‘trees’:

These ‘trees’ are the frames that hold several pieces together. Some pieces are so large that they have their own tree, such as the boom part pictured below. Here you can clearly see how an unpolished piece comes fresh out of our molds. The excess metal needs to be trimmed and polished before we can start our decorating process.




When we trimmed and polished about 3.500 parts, we have enough to assemble two or three models. Especially our tracks take up allot of time to manually trim, polish and connect each individual pad. We apply a double layer of white paint to test paint thickness margins: