R2D2
This is a story about how I made an R2D2 in about 5 weeks and with about $100
This project is one I started because of the theme for my church's VBS in 2007. The theme was "The Spirit Is With You". It was based on the StarWars phrase, "May the Force Be With You." Our skits and centers were StarWars based. Therefore, I was asked if I could build an R2D2.
I said sure, then promptly forgot about it for 8 months. Then about 5 weeks before the event, I was reminded that I was supposed to build one. My first questions were; what is he supposed to do, and what is the budget? Well ,his purpose was to be on stage during the skits, be there to take pictures with, and roam the halls to talk to kids. The budget was about $100.
I started thinking......
- body
- head
- drive motors
- control
- batteries
- sound
Body
I was still looking for an idea for the body and head, while working out in the garage, I looked over and noticed a white 35 gallon barrel sitting around waiting to be a trash can. I whipped out a tape measure, and found out the barrel had a diameter of 18-1/4". "I think this just might work....."
Head
While searching frantically for a bowl or something large enough to use as a head, a friend suggested a ball. I first disregarded it, because I needed a half a sphere, and it needed to be solid. I decided to give up on trying to find something that large, and decided to make my own out of fiberglass. I ended up using one of those large blow-up balls in the large racks at WalMart, slightly over-inflated to match the barrel size. Cut a strip of cardboard to make it slightly taller than hemispherical, and started fiberglassing away.
After about a week of planning, and another week and a half of working on the head and the body, a couple coats of aluminium spray paint, he started to look like something. I also forgot to mention that I had been working on the electronics during this time as well, but more on that later. Next came the feet. I didn't have all of the necessary hardware to gear or belt drive the motors to the drive wheels, so I decided on a friction drive. I built a couple of boxes in the shape and size of his feet, mounted a (scavanged)lawnmower wheel on a bolt, used a small caster wheel mounted on the motor along with a bracket, and then used a spring to hold the 2 wheels tight against each other. I ran some jumper wires over to a battery, hooked it up, and the foot sped nicely accross the floor. Sucsses!!! build another just like it for the other side, and then it was off to the legs. This was one of the harder design decisions I had to make, and in hindsight, I don't think I made quite the right decision. But let's move on.
Legs
I ended up using about 3 layers of particle board (another donation to the project) for each leg. It should have been a little thicker, but the legs were getting rather heavy and they look OK unless you stop and compare them to a picture of the real R2. I mounted the feet on the legs at the pivot point, mounted the legs to the body(more particle board for the stand-off's), and then built and mounted the middle leg with a freespinning caster. Stuck the head back on, and now he's really starting to look like something....