[dremu]

Thanks for the kind words! It's definitely a learning curve, especially if you're not coming from a programming background. But both are increasingly pervasive, especially the Arduino stuff. There's TONS of tutorials on the web, and the hardware is cheap. This truck has sixteen channels of servo control (and could do another ten or so), plus support for several hundred LED's, and the boards were less than 20USD total.

Plus, if you want to do something, chances are somebody else has done it, and Arduino being open source means that they've published it on the Internet for you to use, modify if you like, whatever. Lights are trivial, and even sound effects are simple with off-the-shelf cheap modules. I had one truck done up with an MP3 player that uses a little SD memory card like you use for digital cameras. You could put any number of sound effects on it, so you just google that you want an truck horn sound or the engine startup sound or the hiss that air brakes make when they release or whatever, and you can put all of those onto the chip, and then the Arduino plays whatever sound(s) you want when the throttle goes up or down or stops or whatever.

The CAD is a must if you're printing parts. Thingiverse and such are great to get started, download somebody else's parts, but you'll find very quickly that you want to customize them. Being able draw your own is priceless. OpenSCAD is free, and again, many tutorials on the web.

Some stuff does make sense to fab old school because it's easier/quicker/simpler/stronger, like the basic box for the conex. But doing the detail work is SOOO much easier with a printer; once you get it dialled in, you just keep pressing the "print another copy" button. The ribs for the conex are like that, all eleventy-bazillion of them.