SCOTT GRAY REACTOR HVX REGULATOR SYSTEM
Chris Mulcahy [email protected]
A simple system for more consistent performance
There are many choices to be made when selecting the power setup for your helicopter. I’m not referring to motor power — I mean servo power. In the helicopter world we want speed, torque, and consistency. Until this review I ran a simple 2S (7.4 V) LiPo plugged straight into my receiver to power high-voltage servos, which is common. That worked well for me, so I was curious when I started reading about Scott Gray’s Reactor HVX.
Before I jump into the review: who is Scott Gray? Scott is an accomplished helicopter pilot who has competed in and won many contests worldwide. He’s adept at F3C precision flying and 3-D flight and has been competing since at least the late 1990s. He knows a thing or two about helicopter setups.
Features
- Capable of 25 A continuous output.
- Optimized for use with 3S LiPo packs, but accepts up to 4S.
- Two independent servo buses that can be set to separate voltages (5.2 V to 9.0 V).
- Built-in telemetry port to report pack voltage to a compatible transmitter.
- Push-to-start (PTS) failsafe switch — defaults to on if it detects a problem.
- Quick-charge plug (Deans Ultra Plug with heavy-gauge wire) for field charging without removing the receiver pack.
- Solid aluminum body with machined cooling fins for heat dissipation.
What’s in the box
- Reactor HVX regulator
- Several servo extensions
- PTS switch (push-to-start)
- Instruction sheet
Installation
The HVX is essentially plug-and-play. Plug your servos into one side of the regulator and use the supplied extensions from the other side to connect to your receiver. If you want some servos on one bus at a particular voltage, run the cable from the corresponding channel on the opposite side of the regulator to the receiver.
There is a dedicated servo port for the PTS switch, but you can use a bind plug instead if you prefer. The last port is for the telemetry output.
On my Raptor E700 I have four high-voltage servos — three Futaba BLS255HV on the cyclic and one Futaba BLS256HV on the tail. All are rated for 7.4 V, so I set one bus to 7.4 V and left the other at the default 5.2 V, then plugged the HVX extensions from that side into my receiver.
Mounting and wiring: routing the wires and avoiding chafing against the side frames was the hardest part. I mounted the regulator on the side of the heli, leaving it partially exposed out of the canopy, and used industrial-strength foam tape to secure it to the side frames without wrapping tape around the unit. It’s important to allow airflow over the cooling fins, especially at higher voltages. I mounted the PTS switch toward the rear along with the quick-charge plug; turning the heli on/off and quick-charging the receiver pack became easy without removing the canopy.
JR DMSS users can simply plug the HVX cable into their DMSS receiver and read pack voltage directly on their transmitter screen. Other brands with telemetry may require additional setup or tinkering to use the telemetry output.
Setup
There is a single recessed button at one end of the regulator used for setup. Use a tiny screwdriver to press the button:
- Hold the button for a few seconds to enter setup — the first bus’s blue LED will flash.
- Tap the button to cycle through voltage settings (the settings are indicated by a series of flashes; see the manual).
- Once the first bus is set, hold the button until the opposite LED flashes to configure the second bus.
- Continuing holds/taps allow selection of PTS versus bind-plug operation. Long press to exit setup.
I also switched my receiver battery from 7.4 V (2,000 mAh) to an 11.1 V pack to take advantage of the HVX’s higher input capability.
Flight impressions
I wasn’t sure I’d notice a difference since I had been running 7.4 V already. The first immediate practical improvement was being able to start everything without taking off the canopy.
In flight I noticed the tail felt snappier and quicker after a few quick kicks, and the cyclic and tail felt slightly crisper overall. The more notable benefit was consistency: the controls felt the same throughout each flight in a way I hadn’t noticed before using the HVX. It’s not a night-and-day difference for my skill level, but the helicopter felt livelier and more consistent.
Pros and cons / Conclusion
Pros:
- Consistent, reliable power delivery.
- Two user-settable buses allow mixing high- and low-voltage servos on a single unit.
- Convenient PTS switch and quick-charge plug make field use easy.
- Built-in telemetry is useful for compatible setups.
Cons:
- The unit is somewhat bulky, which can make mounting challenging on smaller airframes.
Overall, the HVX is a great solution for those who want a regulator. It’s easy to set up, offers useful features, and provides the flexibility needed for most setups. My one wish is that the regulator were smaller, but for larger helis and pilots who prefer a separate receiver battery, the HVX delivers the needed flexibility and consistent performance.
—Chris Mulcahy [email protected]
MANUFACTURER/DISTRIBUTOR
Scott Gray Products (519) 208-0361 [email protected] www.scottgrayrc.com
SOURCES
HeliDirect LLC (877) 439-4354 www.helidirect.com
International Radio Controlled Helicopter Association (IRCHA) www.ircha.org
Transcribed from original scans by AI. Minor OCR errors may remain.
