JR Racing: SC-1 forward/reverse speed control

Radio Control Car Action, Apr 2004 by Miller, Nathan

the latest gear tested here

ONE OF THE FIRST UPGRADES many of us make to our vehicles is to swap that clunky mechanical speed controller for a nice, smooth electronic speed controller (ESC). With its SC-1 reversible speed control, JR Racing offers a simple-to-use ESC that's small in size and price but big on performance.

FEATURES

ONE-BUTTOH SETUP. The SC-1 requires only one button to be adjusted to your transmitter. Like many ESCs, the SC-1 requires three presses of this button to set it up: once to set neutral, again for full throttle and a third time for reverse. A flashing LED signals when the throttle should be moved to each setting. The process takes only a matter of seconds, and when it's complete, the SC-1 is set perfectly. The SC-1 doesn't have reverse lockout, but it does require that the throttle return to the neutral position for reverse to engage. This feature is intended to prevent the drive train from being damaged.

INSTALLED WIRES AND PLUGS. Because this ESC was designed with less experienced drivers in mind, it comes completely wired. It includes a Tamiya-style battery plug and bullet motor connectors that make it a drop-in replacement for a mechanical speed control. A universal plug allows the SC-1 to be used with any radio system.

COMPACT SIZE. The SC-1's black case measures just 1.5x1.7x0.9 inches. Its 12-fin heat sink is large enough to help keep things cool, but not so large that it's obtrusive, and that makes the unit easy to install in just about any 1/10-scale car. The power switch is also small, so it's easy to mount out of harm's way.

THERMAL-OVERLOAD PROTECTION. If the SC-1 gets too hot, it shuts off automatically. Once it has cooled to a safe operating temperature, the SC-1 switches itself back on.

HIGH-FREQUENCY OPERATION. With a 1500Hz drive frequency, the SC-1 offers quick forward takeoffs and smooth throttle response in both directions. High-frequency drive also allows more efficient operation, and that, in turn, means cooler running and longer run times.

OTHER FEATURES. The SC-1 can handle 7.2 to 8.4 volts (6- or 7-cell sub-C battery pack) and can take modified motors down to 15 turns. A thorough instruction sheet is included with the SC-1, and JR backs it with a 3-year warranty.

TESTING

After a quick perusal of the instructions, it was time to see whether the SC-1 would be up to the task of an afternoon of backyard bashing. After installing the SC-1 in a Traxxas Rustler, I adjusted it to suit my Futaba 2PCKA. Power came from Orion 24oomAh sport packs, and because the SC-1 can handle mild modifieds, a Trinity 19-turn Caliber provided the propulsion.

The SC-1's high-frequency operation was obvious from the first pull of the trigger; the Rustler shot forward with a vengeance. The throttle response was also very smooth through the entire speed range-no hiccups. The brakes worked flawlessly; the Rustler came to a quick halt. After a quick second tap of up-trigger after I had let the trigger go to neutral, the SC-1's reverse engaged. Reverse was not as quick, but this can be chalked up to the fact that the Caliber's 27 degrees of timing act as negative 27 degrees in reverse.

The fast reaction between reverse and forward made for some slick stunt driving complete with sliding 180-degree turns. Going from reverse to full throttle on high-traction surfaces yielded awesome wheelies.

With just enough downtime to change batteries, I subjected the SC-1 to almost 13 straight minutes of no-mercy run time on a steamy, 80-degree day. If the throttle wasn't mashed, the SC-1 was backing away from trouble or being used to do slides and other stunts. After this punishment, the motor was uncomfortable to the touch, and the battery pack and the SC-1 were hot. Nevertheless, the SC-1 never faltered, and it never got hot enough to activate the thermal-overload protection. For good measure, I put several more packs through the SC-1, and it did everything I asked without hesitating.

THE VERDICT

Although it isn't flashy, the JR SC-1 reversible ESC is a tough customer. It's easy to operate and also sports easy operation and installed plugs that make it perfect for newcomers to the hobby. But because it's a strong performer with a low price tag, anyone who is looking for a reliable reversing ESC should give it consideration. -Nathan Miller

JR Racing SC-1 forward/reverse ESC-item no. JRPSP100; $65.

JR Racing; distributed by Horizon Hobby (217) 355-9511; horizonhobby.com.