Servo - October 2008

Aluminium flipper arm components.

powerful, but heavier. I also experimented with and without

The rear armor plate is missing, showing off the thick titanium armor on top and on the flipper arm.

buffer tanks and with gaseous CO₂, but saw no real increase in performance over the simpler direct liquid injection. This may prove to be different in the arena, but the robot will be completed with the lighter, smaller ram and no buffer tank for now. It will be up to Tom as to how it develops.

See if you can guess what robot

An inspirational ship. Some of the design features are used in this robot.

inspired us so much with this near replica. You may be able to tell from the photos, or maybe you see possible inspiration from several machines. You will have to wait until Part 2 for the reveal, and a full review and performance assessment of the finished machine. I truly hope it does justice to the robot that inspired it. SV

MANUFACTURING:

Combat Rob

t Drive Systems

● by Mike Jeffries

There are many ways to move your robot around the arena floor. From the simplistic two wheel drive robot to the precision crafted complexity of a true walking robot, there are always different methods of movement to consider. When you are choosing a drive system, you have to consider the pros and

cons of each system that makes sense for your design and determine which one is the best fit.

Remember, with proper planning there is no wrong answer.

Two Wheel Drive

Apollyon is the classic two wheeled wedge design. It uses the dragging front wedge to get under opponents.

Two wheel drive robots are as simple as it gets. You’ve got one power source attached to one wheel per side. With only two wheels, there is very little turning resistance which results in a very responsive robot. One problem with two wheel drive robots is that if you don’t have the two sides of the drive system well balanced, it will have some difficulty driving in a straight line at high speeds. Another issue with two wheel drive is that more often than not, part of the

weight of the robot will be balanced over a non-powered component, reducing the robot’s ability to push and accelerate. Two wheel drive robots risk being hung up on uneven floors or arena debris due to the low number of powered contact points.

Many two wheel drive robots will have more than two wheels, using the extra wheel or wheels like casters to keep the chassis from dragging on the ground and to help with driving in a straight line. You should choose two wheel drive if: your design needs to have minimal weight in the drive system; it needs one part of the chassis dragging on the ground; or it doesn’t need a lot of pushing power.