Over the last few months I’ve had a couple of groups of students playing with the Sainsmart 4WD Robot Kit, with quite mixed results.
The Robot Kit is designed as a platform. Once built it’s something you can extend and build upon by adding in additional sensors and so on. It’s not designed to be a rounded finished product in the way LEGO Mindostorms is; it’s more of a development platform. That said, it is designed so that once you have the kit completed you have a functioning robot; it’s just that you can then extend it to wherever your imagination takes you.
First the good parts. The kit isn’t terribly expensive, and gets cheaper still if you get copies from Ebay rather than the original Sainsmart version. It’s well-made and solid, with some nice individual parts. For about $70 you get the metal parts to build the chassis, the wheels, four motors, an Arduino UNO clone, a sensor shield, a motor controller shield, an ultrasonic sensor, and a bunch of wires, screws, etc. That’s all good.
What you do not get for your money is half-way useful instructions. The provided instructions are virtually impenetrable and don’t align with the parts. For example the wiring instructions assume you have a rechargeable battery that requires plugging into an external power supply, while the kit comes with a normal disposable battery pack.
There are a few sets of instructions available on the Internet but they’re a long way short of what you really want to be throwing a set of kids at. So putting this together requires a fair bit of adult oversight and a large degree of willingness to workaround what you have. We found for example that nothing we did would have the batteries power all four wheels and so we had to convert to 2WD. Now there’s a learning experience in that, certainly, but it wasn’t the one we were targeting.
Overall I still think the Sainsmart 4WD Robot Kit is good value for money and I’d happily recommend it to someone experienced with electronics and Arduino. But there’s no way to recommend it as something to get a bunch of kids working on to make their own moon-rover.