Servo - December 2013

28 SERVO 12.2013

BaneBots Large Wheels

Diameter: 2-7/

8-4-7/8 inches

Tread Width: 0.8 inches

Weight: 62 g-143 g

Cost: $5.30-$6.80

Comments:

These wheels are often found on 12 and 30 lb robots.

The range of available durometers (Shore A 30, 40, and

50), size options, low cost, and easy mounting make them a fantastic option for large bots. The 30A wheels have the best grip, but tend to wear out very quickly if you're trying to put a lot of power through them. The 40A wheels have a bit more longevity without sacrificing much traction.

The 50A wheels (which can be bought at www. banebots.com) are the hardest of the bunch and are durable enough that even aggressively driven robots can often go a full event on a set of wheels. The ease of use and near disposable price range make them one of the better 12-30 lb robot wheel options. The large BaneBots wheels are available with a range of mount options including two hex bores, two keyed bores, and two plain bores.

BaneBots Small Wheels With Hex Hub

Diameter: 1-3/8-2-7/8 inches

Tread Width:

0.4 inches

Weight: 11. 4 g-28.4 g (wheel and hub)

Cost: $6.50-$7.69

(wheel and hub)

Comments:

The smaller BaneBots wheels are essentially the same as the larger wheels. The primary difference is that the small wheels are designed to use a separate aluminum hex hub. With bots weighing 3 lb or less, the 30A tread doesn't have nearly the issues with wear that it does on a 12 lb+ robot. You can use the higher durometer treads, but there's not much point.

These wheels give fantastic traction, but the design does have a drawback when compared to its competitors: The solid wheel and hub results in higher forces being transmitted to the shaft. If you use these wheels, make sure to support them well and — if possible — isolate them from the output shaft of the drive gearbox.

BattleKit Robot Wheel

Diameter:

4-10 inches

Tread Width:

1.5 inches

Weight:

1.1 lb- 3. 6 lb

Cost: $39-$49

Comments:

The Colson Performa is one of the longest used wheels in robot combat. It's a durable caster type wheel with a reasonable amount of grip, with a very long useful life. The BattleKits wheel provides the only ready-to-install chain driven wheel on the market. This wheel is designed to be mounted on a dead axle and driven by roller chain. This arrangement makes it easy to build a 4WD bot with only two drive gearboxes, or to build a drive system that protects the gearbox shaft from direct weapon impacts. (For example, the front wheels have the sprockets toward the robot body; the rear ones are away from the robot body with two sprockets on the gearbox shaft.)

One way to get extra life out of the wheel and hub combination is to buy extra casters and use a broach to cut the matching keyway in them. This can be done properly with an arbor press or (lacking that) a drill press and some creativity. Short of taking damage in combat, you can expect these wheels to last a long time.