CAD Modeling

During my career I used 2D CAD occasionally for engineering and design work and I wanted to continue using it for personal projects after retirement. AutoCAD is too expensive for my needs so I chose TurboCAD Deluxe (2021 version) instead. This software’s capabilities have impressed me, especially considering its reasonable cost. I began by creating simple 2D drawings for woodworking projects and soon started exploring TurboCAD’s 3D modeling features.

As a kid in the late ’60s and early ’70s I was fascinated by model railroading and Meccano. Meccano was (and still is) a model construction system invented by Frank Hornby in Liverpool, England in 1901. His goal was to teach children basic mechanical engineering principles from an early age. Meccano is currently owned by Spinmaster, a Canadian toy company, but the parts are now mostly made of plastic rather than metal.

I realized that building virtual Meccano models would be a great way to learn and practice 3D CAD modeling and, at the same time, revive a childhood interest. So, I proceeded to create a CAD library of the roughly 300 Meccano parts that were available in the early ’70s and began computer modeling some of the more complex models I could only dream about as a child. Timothy Edwards’ Meccano website offers an extensive archive of original parts drawings and model instruction manuals. The New Zealand Meccano site (currently off-line) provides detailed information about the various parts and their history. Both have been invaluable references for my CAD work.

I’m still amazed by the mechanical ingenuity of these models—the motors, gears, sprockets, chains, pulleys, and belts—all working together in designs that often consist of thousands of parts. Using CAD lets me build with an endless supply of parts and saves me from the heartbreak of having to dismantle the models in order to build a different one. Still, I sometimes wish I could hold the models in my hands and see them in operation.

All of my Meccano CAD models are based on using standard, unmodified Meccano parts (except for bending or curving them to the required shape). I use steel or copper wire and printed paper to add details, or where they’re called for in the model instructions. Some of the parts, such as the train coupling, were produced by Meccano for only a few years before being discontinued.

Since I didn’t keep any of the Meccano from my childhood, building real versions of these models would first require purchasing all of the necessary parts. I was curious how much that would cost, so I calculated an approximate price for each model (based on the price list of a Meccano parts seller). I was surprised to learn that the cost is in the thousands of dollars for most of the models—and that’s not including taxes, duties, and shipping.

I also enjoy creating near-photorealistic renders of my CAD models and superimposing them onto photographic backgrounds to make them appear life-size and integrated into the original photo. To achieve this, I use fSpy, an open-source camera-matching software tool, along with a program I wrote in C Sharp, to synchronize TurboCAD’s camera position and perspective angle with the photograph. Using TurboCAD’s LightWorks render engine, I can fine-tune the materials, luminance, and environment settings to generate realistic reflections, shadows, and lighting that blend naturally with the background scene. I then use GIMP, an open-source image editor, to add details like steam and smoke—effects that are difficult to create directly in TurboCAD. I don’t use AI to generate any of my renders.

You can see examples of these renders under the CAD Models menu selection. Each image was saved as a high-resolution JPEG at 300 ppi. Clicking or tapping on a gallery image will bring up the high-resolution version.