Step 3: Virtualization & Coolness Enhancement
Using my drawings as a general outline, I start to build my first virtual prototype of the machine. I like this step because you get to see all the details of your general plan come together in the virtual world.
I get out my calipers, and I start measuring all the materials and pre made parts I will be using to the thousandth of an inch.
This can be extremely tedious and time consuming step. But it prevents countless mistakes and predicts many design flaws. For example, with the porting machine I was able to determine where I would have space to put the engine of the machine (a power drill). It allowed me to easily figure out the gearing for the power transmission. It allowed me to make sure I would have enough clearance between the punch and the blank to be able to remove the blank holder from the machine without hitting the stove blank into the punch every time. They all sound like simple enough problems to avoid as you build. But when you add all the numerous small issues together, it's so easy to miscalculate or make uninformed design decisions because you don't have the larger picture in mind. You change one thing, and it can effect every other aspect of your mechanical system. Even with the virtual model there will be plenty of opportunity to deal with unforeseen issues.
The important part is to view this step as a prototyping step. Don't get so stuck on a particular solution that you aren't willing to overhaul the thing entirely if once it's been built in the CAD program, you come across some obvious design flaws. This is one of the nice things about virtual models; they are so easy to rebuild from the ground up with little loss in money and materials. Anyhow, my main point is don't be afraid to start over if needs be.
Coolness enhancement time...
Another enjoyable aspect of the virtualization step is that you also get to finalize some purely aesthetic details of the machine. Things like unimportant fillet radiuses and chamfer dimensions. Often there are multiple ways to aesthetically execute the same idea. In the example of the porting machine, I got to pick whether I wanted to have the blank holder be parallel with the ground, or to have the punch assembly be parallel with the ground. Either way would have worked the same as far as the mechanical system was concerned, but each provided a different feel and look to the machine. I have a years worth of industrial design training from my university experience. To me I get excited about the aesthetics of a machine, and while in a build such as this one I was mostly focused on function and making a working prototype I would take as much time as I could to make it something I was proud of visually as well as functionally. Is it perfect in it's aesthetic appeal? No, but it was definitely worth it to me to spend time on.