The Mk.2

For the past few months I have been working on my second version of a mini-magellan rover. The first version I built was too large to comfortably fit in my Jeep, so I had to downsize a bit. The Mk.2 is a three wheeled “tail dragger” robot that uses proportional skid steering.

Rover Mk.2

Rover Mk.2

This pic gives a good overview of the robot. My design philosophy for this ‘bot is overkill, durability, and reconfigurability. The main body is 1/2″ Pine, with a nice coat of stain and a few coats of polyurethane. Building the body out of wood is easy, cheap, and gives the ‘bot a funky retro look. Plus, if things go horribly wrong, I can recycle it into a breadboard or something. 🙂

Durability: I expect this robot will be encountering some rough terrain as it does it’s job, so durability is a priority. I am using terminal strips and connectors for everything so nothing bounces loose. The motors are kiddie car “PowerWheels” motors from a local surplus store. The 12v batteries were intended for use in a UPS, but another local surplus store (Gateway Electronics) had them on sale for $10. Everything is bolted and lock nutted, and this thing is strong enough for me to stand on.

Overkill: The 12v batteries are wired together for a longer run time. I would like to get an hour out of each charge, but that has yet to be tested. The PowerWheels motors are designed to haul around a small kid, and are designed for kiddie abuse. The wheels/tires are utility tires from Harbor Freight, and are rated at 300 lbs. of load each. The handheld GPS is far more powerful than I really need to drive a mini-magellan course, but it has some nice features that might come in handy later.

roverwheel

Reconfigurability: One thing that I have found is that things change on robots. A new sensor, different batteries, new motors, etc. I don’t want to be locked in to a particular setup, so everything can be easily disconnected and reconfigured. Terminal strips and connectors make it easy to access the pins on the microcontroller, 12v power, sensors, etc.

Advertisements

One Response

Comments are closed.

%d bloggers like this: