Servo - April 2010

PARTS IS PARTS: FingerTech Robotics’ Spark M tor Series Finger Tech Robotics ( www.finger techrobotics.com) has a new line of motors. Following my policy of only using this space to feature combat tested products, I delayed reviewing them until the head of Finger Tech, Kurtis Wanner, had some combat data under his belt. Kurtis assures me, “January’s Kilobots XVI and the University of Saskatchewan’s Sumo competition put almost 50 of these motors through their paces. There were only a couple mechanical failures that weren’t caused by direct combat damage or overvolting the motors.” Since then, Finger Tech has instituted a 100% testing policy for each motor, under load, before shipment.

● by Kevin Berry

assembly is a little over 1.5 inches long and 0.6 inches in diameter. The shaft adds up to another 1.5”. Torque specs are shown in Figure 1.

Fingertech worked with the manufacturer to battle-harden the gearbox. Figure 2 shows a beta version of the added support plate. According to Kurtis, “the indicated plate did not exist in their standard gearhead. The main shaft has one large gear pressed on, but also another gear that spins freely on it. Without the new plate, the thin shaft would snap between the two gears when any large sideload was placed on the shaft. Now it is supported by: 1) the faceplate bushing; 2) the new support plate; and 3) the old

FIGURE 1

FIGURE 2

Spark2 Original.

carrier (end of the shaft).” Responding to my questions about testing and toughness, Kurtis supplied the photographic evidence (Figure 3) of how effective the three point support system is. He says, “This is a test I did with one of my modified motors; 20 lbs hanging off the end of the 1.5” shaft. The motor ran afterward without even a hiccup.” Even though I personally haven’t used these motors yet, I’d say the jury is in. Good ‘nuff! SV