TEST BENCH
tried • tested • tortured
Tekin RX4
Tekin steps up the speed control game
In recent years, the crawler scene has grown in popularity, and Tekin jumped into that market with speed controls that were capable of running brushed
or brushless motors, applying drag brake, and
so on. After time on the trails, Tekin has taken
what it has learned and developed a speed
control specifically designed for trail riding and
rock racing. It’s called the RX4 and it comes
in a thick waterproof case (which is a first for
Tekin), and it’s designed to do everything that
the trail-riding and rock-racing scene needs
it to do. Let’s open this thing up and see what
makes it tick.
Features
When you open the box, you are greeted by
a good-looking dark gray plastic case that
houses the speed control’s electronics and heat
sink. The case extends above the heat sink
and provides a mounting place for the included
brushless fan if you choose to use it. The case
is also waterproof (which is new feature for
Tekin), and included in the package is a tube
of Dielectric Tek grease to waterproof any
open ports. Protruding from the case are five
gold-plated solder posts; two are used for the
battery wires, while the other three are where
you solder the motor wires. The speed control
is designed to run brushed as well as sensored
or sensorless brushless motors. If you choose
the sensored brushless route, a port on the top
of the speed control can be used to attach the
sensor wire. A second port on top of the RX4
specs
Controls: Forward/brake/reverse
Input voltage: 2S–6S LiPo
BEC: 6.0v/7.4v 8 amps
Motor limit, brushless mode: 2S—5700Kv
4-pole; 3S—3500Kv 4-pole; 4S—2300Kv 4-pole;
5S—1800Kv 4-pole; 6S—1350Kv 4-pole
Motor limit, brushed mode: No limit
Max current: 240 amps per phase
Timing profiles: Seven choices
Brushed modes: F WD only/FWD-REV/
F WD-REV delay
Brushless modes: FWD only/FWD-REV/
F WD-REV delay
Dimensions: 1.6 x 2.0 x 1.4 in./40.6 x 50. 8 x
35.5mm
Weight: 2. 65 oz./75.5g
is used to connect to Tekin’s Hot Wire and/or
power the cooling fan. In the near future, it can
also be used to connect the speed control to
Tekin’s BLE unit, which will allow an open channel on your radio to be used to adjust drag brake
on the fly. Setting up and programming is done
through the two buttons on top of the speed
control. On the electronic side of things, you’ll
find a high-voltage adjustable BEC, dual-drive
mode technology, onboard temp sensing, self-test diagnostics, and digital glitch filtering.
InstallatIon and setup
The RX4 is rather large for a speed control, so
before you pick one up for your rig, you may
want to check the space that you have available to make sure that it will fit in your vehicle.
I decided to mount mine in my Axial Bomber
project truck; it has a large carbon-fiber
mounting plate on which I had an RX8 mounted,
so I knew that I’d have plenty of room since the
RX4 is slightly smaller. Before mounting the
speed control, I installed the fan; I had a little
trouble getting the plug installed into its port
on top of the speed control. The opening is only
slightly larger than the plug, and that required
me to spend a little more time than it should
have to line up the plug properly and set it into
place. Installing the RX4 onto the mounting plate on my truck was easy; I cleaned the
mounting surface and bottom of the RX4 and
connected them with a large piece of double-sided tape. Before soldering the included wires
The RX4 from Tekin comes
with a gray waterproof
case and easy-to-use
solder posts. A fan is
included, which you
can install or leave off,
depending on how hard
you’re going to push the
speed control.
