Prototyping was the most exciting part of the first couple of years of this car project. A 3D model on a computer screen is nice, but it does not compare to actually holding the real part in your hand. Back in 2006 I received the first parts, which I could builld and look at, but they weren’t strong enough for anything else. I used them to get a better idea of what THE Car would look like, and to make sure everything would work right throughout the suspension movement.
The first prototype I had, was a pretty cool showcase of modern technology. How did people do it in the past? All of the plastic parts were made without any moulds. Moulds are expensive to make, and can only be changed in limited ways. When a mould for a part is made, the part is normally considered to be ready. Not one single part on this car was considered ready, so what to do? Rapid Prototyping, or 3D-printing in layman’s terms that’s what! What a great method to produce prototype parts. All that is needed is the 3D CAD file, and the machine that will make the part of course. No moulds or special tools needed, and the shape of the part is completely free. It’s possible to make parts that cant be produced in other ways, milling or moulding, although that wasn’t the case here, as these parts would have to be moulded or machined in the future.
The way it works, in this case Stereolithography (SLA), is that a flat plane is lowered into a special liquid resin, so that a thin layer of liquid covers the plane. A UV laser then solidifies the liquid in the appropriate places. The plane is then lowered so a new thin layer of liquid covers the newly solidified areas, and then the laser solidifies more liquid in the right places. The parts are built up in thin layers in this way. With this system it is possible to make all kinds of shapes, including hollow ones. Normally the finished part is very brittle, and not suitable for any testing on an RC Racing car. But just like everything in this world, rapid prototyping techniques and materials are developing fast, and I was lucky enough to be able to get hold of some new, stronger, more flexible material, that proved to be ideal for the gearboxes, radiotray, part of the 2-piece centre-diff mount, and front and rear hubs among other things. These parts were made by Selective Laser Sintering (SLS), where nylon powder is sintered (melted) layer by layer. The plastic was white so it made the car look quite cool I think.
Steering knuckles was a problem, because it would be so expensive to get them machined. My mate, who is a genius when it comes to prototyping stuff, calmly informed me that there is no need to worry. A new technique for moulding aluminium, Investment Casting, using Multi Jet Modelling (MJM), sounded too good to be true. First a rapid prototype of the part is made, like I explained before. This is called the master model, and it is placed on a wax tree, that is then cast into plaster. The rapid prototype and the tree are then melted and poured out of the new mould. Then aluminium is cast in vacuum into the mould and left to solidify. The last step is to simply break the mould, and voilà, THE Car has its first aluminium steering knuckles. I never knew that was even possible. Zero milling required. Just a bit of dremel work to get the knuckles cleaned up from the moulding process.
For the first proto, the chassis, diffs, enginemounts, centrediff mount etc were machined as the parts from other cars wouldn’t fit. Driveshafts, linkages, top links, and wheel hexes I took from other cars, and modified them to fit where needed. It was a lot of work but it was worth it. Zero moulds, (well two for the knuckles), but many parts on the car already looked like the production versions, only they were white.
The First Prototype being tested in Greece. Still not my body or wing.
The next step for the prototype made it even better for testing. My first partnership ended when the global economic crisis hit, but we had already produced some test shots of plastic parts, from the actual moulds. So I now had the wing mount parts, receiver and battery boxes, and chassis braces. Furthermore, my friend had found a better material for prototyping the parts, and I now had rapid prototype lower arms that were strong enough for driving normally! I couldn’t believe it, it was so strong, yet flexible like a real arm, that I could do all the jumps, and even have small crashes, and it wouldn’t break. This was really good, as I was able to test all different arm lengths and designs easily. This was the prototype I used for the most important step of testing, where I decided on which parts of my many variations to actually choose for production.
·What I believe to be the 2nd prototype generation, which I tested among other places in Venezuela.
This proved to be very difficult. Throughout the end of 2008, and all of 2009, I had a prototype car, where all plastic parts were rapid prototypes of my designs, and all the important metal parts according to my designs. I borrowed diffs off the Xray and Hobao, and had special crowngears made, so they would fit. I modified my own gearbox design so the bigger Xray diffs would fit. I didnt have my own shocks, so I used Losi, HN, and Xray, and mixed and matched parts to be as close to my design as possible.·
I had a ton of different ideas, and different versions of arms, arm holders, shocktowers, steering systems, everything you can think of really. It was really hard to pick the right parts, and settle on a direction to go in. I knew I needed to do something different to the rest, or else there was no point in making THE Car, because it wouldn’t be THE Car, it would be A Car. So I actively tried to find something that would make a difference. Finally I did, and I chose a few new ideas to pursue. Eventually I reached a stage where I couldn’t go any further. I had hit the wall. A prototype can only be tested to a certain point. To see if I had managed to create something great, or an epic failure, I needed to get the thing made. The actual car made out of the actual materials, with all parts just like I had designed them was the only way I was going to be able to move forward. I still had some things on my design I didn’t know if I could get to work perfectly on all tracks, but I wasn’t going to just make it the same as all the others, so I had to take that risk.
·So many different parts to chose from!
Because of all this work that I had put in, and all the help I had received from friends and fellow RC Racers, be it producing prototypes or helping to build them, there was no way I was going to give up on THE Car. I had started everything in 2006, it was supposed to be produced in 2008, then in 2009, and nothing happened with that. For 2010 I decided that enough was enough, and I decided to do it myself, like I explained in my first 2 stories.
So it became a joke, but I will have the last laugh….