I've been collecting ideas for building a Mars Rover. This can easily cost a few thousand dollars so I'm not quite sure I'm willing to fund such a venture, but it's fun to dream (and plan).

Apparently lots of people have been inspired by the NASA Mars rovers, as there's lots of projects out on the Web. NASA has even created an "open source" robot project, with downloadable plans.

Design Notes#

Open Source Rover Patch (click to enlarge)

So far I've been scanning the cool robot parts at ServoCity for ideas for the steering mechanism and rocker arms. The scale and weight of the overall robot help decide the size/power of the motors and servos. It's a bit of a balancing act. I also want to, unlike most of the "civilian" designs, somehow tuck my motors inside the wheels or otherwise not have them hanging down near the ground as many/most of the rovers I've seen seem to do. There's a huge impact on ground clearance if your motors are down there banging into rocks and such. The difficulty seems to be locating some suitable wheels. I can't imagine simply 3D printing them, as plastic wheels wouldn't last very long on rocks or concrete. I want a robot that can actually roam outdoors.

Rocker-Bogie vs. Triple-Rocker Design#

The ExoMars (and ExoMy) robot uses a simpler "Triple-Rocker" design.

Specifications#

I'm going to (initially) steal the specs from the JPL Open Source Rover Project, as a point of reference. Their robot is a bit larger than I'm planning and has an estimated cost of around US$2500, and that's certainly at the upper limit of my budget. But it's a start.

AttributeValue [imperial]Value [SI]
Weight28 [lbs]12.7 [kg]
Footprint24x14 [in]60.96x30.48 [cm]
Battery Capacity5200 [mAh]5200 [mAh]
Battery Discharge Rate8 [A]8 [A]
Nominal Current Draw1.2 [A]1.2 [A]
Operating time5 [hrs] (continual use)5 [hrs] (continual use)
Approximate Max speed68.8 [in/s]1.75 [m/s]
Maximum 90 deg vertical scale12 [in]30.48 [cm]
Maximum height differential between sides14 [in]35.56 [cm]
Communication (in this guide)Bluetooth app (Android only) and Xbox Controller 
Cost (*)$2,500 


Tags:  Mars Rover