This year I think I have finally located the outer limits.
Modifying Barbie Jeeps is actually a complicated task. The wiring needs to be done properly (kids are not good at crimping and soldering), and if you do any mechanical alterations you will be working in cramped quarters and with lots of constraints.
It can be done with a small, motivated group who are willing and able to work together. With a larger batch of, shall we say, Free Spirits.....the amount of actual teaching as opposed to crowd control has started to tip.
The section working on Ninja Jeep has nevertheless made progress. I don't always have time to line up good pictures so I missed the shot where a half dozen kids gave a "thumbs up" the first time the Jeep powered up and ran. But here's what I did capture.
A reasonable coherent control box.
The kids are big into flashy lights. The front police style light and the rear strobe lights work great. The rear wheel motors are wired into the control system. We have three sessions left to remove the front wheels and convert to 4 wheel drive. If that effort fails we just put some kind of roller skate under the front and go with what we've learned. A few actual good decisions were somehow made on the design and layout of this beast. And we have a buzzer/horn that we'll add next week.
The other class section has the advantage of fewer excitable members, and has two students that I've worked with on advanced projects in the past. They also have fewer build sessions. I figure it will be a wash. So lets get underway with Princess Jeep....
Or not. We dug out the innards of the other Jeep and found...problems. The wire gauge was not big enough to handle 24 volts without heating up. And one of the gearboxes had stripped gears. Efforts to get access to this resulted in glitter everywhere, frustration and no success.
So we'll abandon the Evil Princess Jeep and have both classes work on the Ninja. They are at this point mostly interested in bling and a functional water cannon so we'll try to oblige....