Pneumatic Control Unit-PCU
The JMP Pneumatic Control Unit is
designed to control the brakes, retract gear cylinders and landing gear
door cylinders of the most complex r/c model aircraft. The goal of the
PCU is to eliminate the complexity and disorganized nature of model
pneumatic systems. Most installations have many t-fittings which cause
unavoidable pressure drops across the entire system. This is eliminated
with the PCU. Also included with the PCU are individual servo linkages
and quality 1” readable pressure gauges for each of the three air
circuits. The overall size of the completed PCU is 5.5” in length and
3.5” in width. From the top face of the gauges to the bottom edge of the
brake servo it is 2.0” tall.
Either standard 1/8” OD or 4mm
fittings can be ordered. Large models with increasing air cylinder
diameters often now use 4mm size air lines. When ordering, let us know
the number of retract gear cylinders and gear door cylinders and the
proper fittings will be installed. Additional unused ports on the PCU
lower side manifold are plugged, but can be changed later for some other
model with different cylinder counts. Many combinations of fittings and
control possibilities can be imagined.
The PCU can use three individual air
supplies which will divide the retract gear, gear doors and main wheel
brakes into separate air circuits. A manifold air fitting point for the
JMP Failsafe Sequencer is also provided. This Sequencer senses a low air
supply in the retract gear air circuit and shifts the retract gear and
gear doors to the down position. Robust servos control the High Flow
2-Way Valves and proportional Brake Control Valve. Precision 1-Way Fill
Valves are mounted to the PCU and feature a very neat and quick Tapered
Filling Adapter. Also available is a more standard 1-Way Valve with a
screw in fill fitting.
Single point control units have been available for
some time. Their miniature control valves are fragile and unreliable.
These valves are controlled by very weak actuators. Difficult and
painful programming is found on nearly
every one of these units. They are also produced offshore with no real
way to deal with manufacturing and programming problems. Multiple
manifold type air line attach points are not found on these digital type
units. The “Old School” nature of the PCU makes it easy to use and deals
directly with air line and plumbing challenges found in easy to complex
2-Way Valve 59.95
The new JMP 2-Way valve is the
finest and most robust servo controlled valve built for RC models. The
spool design uses quad seals with definite end stops. Its vertical
design allows the air lines to remain hidden. It is truly a high flow
valve and may be ordered with hose barbs for 1/16" i.d. air line or 4mm
The new JMP 1-Way Fill Valve is a
precision machined check valve. It uses a checking concept found in
expensive demanding aerospace equipment. Mounts to the model's control
board using a washer and nut. The JMP
Adaptor provides easy
connect and disconnect to the air supply. Available with hose barbs for
1/16" i.d. air line or 4mm air line.
1-Way Fill Valve 39.00
Tapered Fill Adaptor
A simple but
effective way to couple your air pump to the 1-Way Fill Valve. Just push
the tapered nylon fitting into the valve to create a temporary seal. The
air line automatically recoils, stays neat and out of the way.
NEW JMP Air Trap
The JMP Air Trap uses a proprietary
fiber membrane to filter fuel to 10 microns and virtually eliminate air
from entering the final fuel pump suction line. Smoke systems are also
improved with use of the Air Trap. This design is extremely robust with
properly designed end caps that deal with positive and negative
pressures often found during fast fuel filling and draining. Either the
vertical or horizontal versions have CNC machined mounting tabs with
Laser printed front caps pointing out the correct fuel tube attach
points. The JMP Air Trap comes completely assembled, leak checked and
ready for installation.
The Air Trap has positions for two
“Fuel In” hose barb fittings that can be used for twin main fuel tanks.
One of these “Fuel In” fittings can be blocked if there is a single main
fuel tank requiring only one fuel inlet fitting. A center hose barb
fitting attaches to the fuel filter membrane. This is the “Fuel Out”
position which delivers fuel to the turbine fuel pump. Also, a
drain/fill line is provided.
Hose Barb Fittings: The JMP Air Trap
is available with hose barbs to fit either 1/8” i.d. or 3/16” i.d.
tubing sizes. Many combinations of the two are also possible.
Construction: The Air Trap is
constructed from aircraft grade aluminum and the finest West Systems
Epoxy with a main body that is translucent. It is easy to visually check
for system air leaks and overall fuel system performance.
Proper Filling: The fitting with the
smaller hole is for the fueling/de-fueling line. Do not allow any air to
enter this line when removing the fill line from the fueling station.
Fold this fill line over in your hand when the tanks are full and
install the plug. Very little air should show in the Air Trap when the
fuel tanks are completely full.
Proper Operation: Typical clunk
style fuel systems found in model jets do not deliver fuel perfectly,
especially when the model fuel tanks are near empty. Some air is normal
to see in the Air Trap. An amount of air that would leave the Air Trap
half full is not good. Either the main fuel tanks were run very low or
there may be a leak upstream in the fuel system. This should be checked
Proper Orientation: The vertical
design Air Traps are normally mounted straight up and bolted to the
model control board. The horizontal design Air Traps are normally
mounted with the mounting tabs bolted down to the model control board.
On the horizontal design, this keeps the “Fuel In” fitting to the top.
If you decide to mount the horizontal design Air Trap upside down to the
bottom of the model control board, you must reverse the “Fuel In”
fitting and the “Drain/Fill” hose barb fittings. Drain/Fill must always
happen from the lower side of the Air Trap. Just remember that air in
the system must be forced up and out during the filling cycle leaving
the Air Trap completely full of fuel.
in 4 sizes and 2 mounting options!
Please specify when ordering:
Horizontal Mount-1.5”x 3.25”-2.9 ozs.
Vertical Mount-1.5” x 3.25”-2.9 ozs.
Horizontal Mount-1.75” x 3.75”-4.66 ozs.
Vertical Mount-1.75” x 3.75”-4.66 ozs.
Horizontal Mount-2.25”x 4”-8.8 ozs.
Vertical Mount-2.25”x 4”-8.8 ozs.
Horizontal Mount-3”x 5”-19.5 ozs.
Vertical Mount-3”x 5”-19.5 ozs.
option for each line:
1. Number of “Fuel In” hose
fittings 1___or 2___
2. Size of
“Fuel In” hose fittings 1/8”___or 3/16”___
3. Size of
“Fuel Out to Pump” hose fittings 1/8”___or 3/16”___
4. Size of
“Fuel/De-Fuel” hose fitting and fuel line plug 1/8”___ or 3/16”___
Large Fuel Tank Fittings
These large fuel fittings are
designed to minimize tank and pump pressures during fueling-defueling and running of the
turbine. For 3/16" I.D. Tygon fuel tubing.
Machined arms and mounts are available
for the HiTec 5755 metal gear servo.
These parts are designed for heavy-duty applications requiring power and
holding strength. The servos are somewhat larger than standard sizes and
feature an extremely large and tough gear set.
MACHINED SERVO ARM....... 75.00
twin vent overflow tank is designed for models with one or two
fuel vents. The extra-large fuel fittings and tubing help to
lower the pressure caused by fueling at a high rate.
VENT OVERFLOW TANK 50.00
JMP’s HUSTLER 100 oz. CENTER
fiberglass tank will deliver either turbine engine fuel or smoke fuel
engine. A JMP Accumulator is embedded into the tank to save valuable
fuselage space and deliver a bubble free fuel supply to the engine or
smoke pump. The center baffle controls rapid fuel weight shift. A
machined aluminum truss provides for easy mounting in the Hustler
airframe or other similar model designs. This JMP fuel tank comes fully
assembled and leak tested for the perfect fuel delivery system.
SMOKE TANK 250.00
Please visit the "Accessories" page for more great products.