Robot Bases


Everything has to start somewhere, and for robots it is the base. The base of the robot is like the foundation of a house. You want one that is big enough to hold your stuff, and stong enough that it will not break. Oh yes, you want it light so the motors and batteries will not have to be huge.

My first autonomous robot code named RADAR will have an octagon base. Half inch plywood will be used since it is readily available, reasonably inexpensive and light weight.

For a size, I need something to hold all the goodies, and yet not be too large to go through a standard door. 18-20" should be about right. The formula for octagons indicates:

LengthOfSide= 2 Radius sin(180/NumberSides)

= 2x10 sin(180/8) ; for 20" diameter

= 7.6537

Of course AutoCAD made it easier, but it was nice to know the math works! Using AutoCAD shows that the distance side to side is 18.361" so using the LengthOfSide we can start building!

I am going to cut two identical full bases so there will be two tiers. The lower level will be motor and battery housing. The upper level will be electronics, fridge, vacuum and sensors.

April 25 - Removed the drive gear that was press fit on the motors. Examined the selection of very inexpensive wheels to find the one most suitable to press fit on the motor shaft. Drilled out the plastic on my drill press to press fit. Then I used polyureathane glue to ensure a good bond (this glue sticks anything to anything, but is really messy to use). After setting up the motors with wheels, the base was cutout using a drill and jigsaw. Room for the wheels plus some clearance, as well as grooves for the motors was cut with a router. So far so good. Once the motors were in place a spacer was cut for the back swivel wheel to make sure RADAR will be as level as possible.

April 29th headed off to the do-it center and found some metal plates used to reinforce joints (called mending plates). These appear to be heavy enough gage to work as mounting plates for the motors. One per side should be ok.

Stay tuned to the saga of RADAR!