Servo - December 2013

Sabertooth 25

Dual Motor Controller

Voltage: 6V–30V

Current: 25A continuous, 50A peak

Dimensions: 2. 6 x

3. 2 x 0.8 inches

Weight: 96 g Cost: $130.99

Features: Regenerative braking, current and overtemp protection, LiPo protection mode.

Comments: The Sabertooth 25 is a versatile controller, with many options for inputs and dip switches that allow a range of parameters to be quickly and easily changed. While versatile, the Sabertooth 25 can be fragile; a common recommendation is to coat it in a thick silicone adhesive (Shoe Goo and Goop are common options) and to shock mount it to reduce the risk of shock induced failure.

If you don’t expect high shock loads in your application and you need the versatility the Sabertooth offers, it’s worth considering.

Robot Power Scorpion XL

Voltage: 4.8V–28V

Current: 12.5A continuous,

45A peak

Dimensions: 2. 7 x

1.6 x 0.5 inches

Weight: 28 g

Cost: $104.99

Features: Current and overtemp limiting, dual channel, flip control, channel mixing.

Comments: The Scorpion XL is the smallest dual channel ESC intended for 12 lb robots. With the low continuous current rating, this controller is best suited to weaponed robots with mid to low powered drive systems (if it is being used in the 12 lb class). The small size also means it is possible to put it into something as small as a

1 lb robot. However, trying to use it in anything below the 3 lb class is excessive. In the case of a 3 lb bot, it would be best suited to a rammer or wedge with a very demanding drive system. The small size and light weight make it a good candidate for 12 lb robots that are tight on both space and weight.

Robot Power Scorpion XXL

Voltage: 6.0V–28V

Current: 20A continuous,

45A peak

Dimensions: 3. 27 x

2. 27 x 0.5 inches

Weight: 52 g

Cost: $159.99

Features: Current and overtemp limiting, dual channel, flip control, channel mixing. Comments: The Scorpion XXL is the larger cousin of the Scorpion XL. With the increased weight, size, and current limit, this controller would pair well with many 12 lb drive systems and may be capable of running lower powered or weapon focused 30 lb drive systems. The small size and light weight make it easy to fit into 12 and

30 lb robots that are tight on space and weight.

FingerTech Robotics TinyESC

Voltage:

6.5V–36V

Current: 2A continuous,

3A peak

Dimensions:

0.53 x 0.90 x

0.19 inches

Weight: 4. 5 g

Cost: $33.99

Features: Undervoltage protection, overcurrent/temp protection, BEC.

Comments: The Finger Tech TinyESC is — in effect — the default controller for the 150 g and 1 lb classes. Its small size, light weight, and wide voltage range make it a great option for most robots in those classes. The TinyESC has also seen use in the 3 lb class, though it hasn’t gained the same grip here as it has in the 150 g and 1 lb classes. The TinyESC has been tested and is proven to work with some of the common drive motors used in 3 lb robots, though it is suggested that you solder the included 0.01 µF capacitor between the motor leads when using TinyESCs in a 3 lb bot. These ESCs are tiny, highly reliable, and offer smooth control.