together and then the connectors snap securely into the housings.
They’re impossible to connect incorrectly, are easy to grip and use, and
provide good protection from electrical shorts.
XT connectors are bullet connectors that are molded into a uniquely
shaped yellow nylon housing. XT60s have 3.5mm bullet connectors
with a rating of 60A, while XT90s have a 5mm bullet and 90A rating.
Since the connectors are molded into the housing when manufactured,
wire is soldered to them in place and covered with heat-shrink tubing
to insulate the bases of the connectors. Some XT connectors have a
molded cover that snaps to the base of the plug and provides insulation
for the wires. They’re easy to assemble, are well polarized to prevent
connection mistakes, and have good gripping surfaces.
Polarized Cas Tle ConneCTors
Castle Creations has a green plastic connector housing offered in a
couple of sizes. The smaller one uses 4mm bullet connectors and is
rated at 75A. The large size carries 6.5mm bullets and has a 200A rating.
Both sizes are polarized, are easy to grip, offer great protection, and use
Castle’s solid pin contact design instead of a spring design. To assemble
them, the wires are passed through the housing and soldered into the
cups on the base of the connectors. Then the connectors snap securely
into the housings. Castle also sells bare bullet connectors in 4mm,
5.5mm, 6.5mm, and 8mm sizes, which are well suited for connections
between the speed control and motor.
Fla T Blade
A second type of contact
utilizes flat connectors.
Electrical connection is
made by two blades of
conductive metal sliding
together that are held in
tight contact by a spring
in the housing. Like
bullet connectors, these
connectors have good
connection properties when
The Optipower Ultra Guard 430 is small, only weighing about 40 grams. It’s
simple to install and easy to maintain, as it charges itself from the primary
The original red Deans Ultra connector and an improved version of the Star Plug. The Star Plug has grips molded into the plastic and a
segmented cover for the solder connections that helps prevent wire contact.
The EC5 connector is a polarized housing for 5mm bullet connectors used by
Horizon and E-flite, among others.
The XT60 plug is fast becoming the standard for multirotors and racing quads.
Some charger manufacturers are using them in place of the commonly used banana
jacks and plugs.
OptipOwer Ultra GUard 430
One of the things we learn as RC fliers is that eventually everything
fails. I checked a 2S A123 receiver battery just before a flight
recently and found that it had done just that. As I packed up and
headed home, I decided I was pretty lucky that it hadn’t failed in
flight and cost me a plane. But the more I thought about it, the
more I wondered if there was a good way to safeguard against that
happening to me. As it turns out, there is.
Optipower’s Ultra Guard 430 is a battery-powered smart backup
system for RC receivers. Its purpose is to give a pilot enough power
to land a model in case of a failure in the primary power supply,
whether that’s a battery or a BEC (battery eliminator circuit). One
of the biggest advantages it has over other similar products is that
it charges and maintains the 2S 430mAh LiPo battery as you fly on
the main power source, so it’s not yet another battery to monitor
and maintain. If the main source voltage drops more than a half-volt,
the Ultra Guard takes over and flashes a bright LED to let you know.
There’s an extension LED so that you can mount it in a more visible
Small and light, the Ultra Guard senses voltage from 2 to 8.2 volts
and is rated to provide 5 amps continuously and 10A intermittently.
It plugs into the receiver via a universal connector and uses the
JST-XH balance tap from the LiPo to power the main board and LED.
Available from optipowerbattery.com, the Super Combo includes the
Ultra Guard and additional LED for about $55.00.