Servo - March 2009

to the robot’s chassis through screws or welded joints, these types of wedges are generally more durable and less likely to be torn off of the robot. Shock mounting fixed wedges has also become popular in the 12 pound and up weight classes. This process involves mounting the wedge to the robot’s chassis through rubber sandwich mounts. This isolates the robot’s chassis from shock and allows the wedge to take more of the impact from the blows.

Beyond the way the wedge is mounted, there are two final variables I’m going to mention: angle and material. Both of these aspects go hand in hand. A wedge can serve different purposes, depending on the angle. A shallower wedge can slide under spinners and other robots with ease, and hits from the

FIGURE 6. Antweight “Misdirected Pedestrian’s” steep anti-spinner lifting wedge plow shows how wedges can be used effectively in other designs. This robot’s wedge plow takes about 95% of spinner hits directed at the robot, and only a few small scratches can be seen on the rest of the robot’s body.

aforementioned spinner will simply bounce off of the wedge because of the shallow angle. Wedges with steeper angles are meant to be much more of an attack method against spinners. Instead of sliding under the weapons, the objective is normally to simply slam into the weapons and have them bounce off in a dramatic manner — possibly causing damage to the spinner instead of its intended target.

As stated previously, the thickness needed for the wedge’s material is directly proportional to the angle of the wedge. A shallow wedge that is designed to simply slide under an opponent will take many less solid hits than one intended for use as a much more offensive wedge with a steep angle. Thus, the steeper wedge would require much less thickness from the same material.

In conclusion, I’d like to say this — I hate slow, boring wedges — even the brightly colored ones — just as much as everyone else, but

contrary to what it may seem, there are a good amount of fast wedges that can be just as exciting as any good spinner. I know this for a fact, as I personally own one that has actually damaged the arena and disabled spinner’s weapons on occasion.

If you still think that wedges are bad for the sport, why not add something else to the table? Wedges can be effective with clamping arms, lifters, and spinning weapons mounted to the robot, usually in which case the wedge will help lead the opponent up to the weapons. Also (as stated earlier in this writing), wedges always make an effective backup weapon when constructed reliably. When your robot’s main weapon fails during a fight, it’s much more effective to be able to get under the opponent and bully them around as opposed to simple pushing.

Finally, I’d like to note one tip that’s constantly overlooked by many builders of dragging wedges — Sharpen your wedge and do your best to get it as close to the ground as possible! The robot with the lowest wedge always wins ... at least in wedge fighting. SV

MAN UFACTUR IN G:

Attaching Wheels to Your

Rob t’s Drill Motors

Drill motors are often used in 12 and 30 lb robots. One of the hard parts about using them is finding a way to attach a wheel, since the shaft is threaded and uses a lefthanded screw to keep the chuck from coming off. Here, I will show you a simple way to make press fit hubs to mount Colson wheels to your drills.