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CARF-Models P-47
Both JET Tronics Valves must be Reset with NO throttling (the Default setting is 3 seconds of
throttling – this must eliminated). Reset the JET Tronics valves by turning off receiver, holding
both blue valve buttons down at the same time, then powering up receiver. This should reset
valves to no throttling of either output. You may need to repeat this procedure.
To set up the correct delays, plug both retract valves into the Receiver's Throttle channel. Make
sure throttle end-points are set to 100%, trims and sub-trims are at 0. Count the number of clicks
from zero to full throttle stick deflection such that a calculation of percentages can be estimated.
Example: IF throttle stick has 26 clicks from low to high throttle, then:
• 5 clicks = 20%
• 7 clicks = 25%
Move the throttle stick to 20% throttle. Press the green button of the Main gear valve. Move the
stick to 25% throttle, press the red button of the Main gear valve. Now move the stick to 80%
throttle. Press the green button of the door valve; move the throttle stick to 85%, and press the red
button of the door valve.
If programming of the switch points was successful, you will be able to test the functions by
moving the throttle stick slowly from idle to full throttle, and back to idle. The valves should
retract the gear first, then close the gear doors and TW; the slower you move the stick, the later
the doors will close. Conversely, throttling down should open gear doors first, then extend gear.
This "time delay" of the slow moving throttle stick can be simulated by setting a Channel Delay
function onto your gear channel. Plug the valves back into your original gear channel (make sure
the end points are set in the transmitter to +/- 100%) and set the function of your transmitter
Retract Channel reduce (delay) servo speed. On some radios, this can be independently set for
either direction. Set the servo slow function to approx. 3 seconds (or some percentage), then
activate the Retract switch. You will see that this simulates the slow moving throttle stick as you
observe the timed operation of the JET Tronics valves in both directions.
Maximum reliability can only be
achieved when maximum air pressure is
applied to both cycles (gear up, gear
down). However, slower gear and door
speed can be obtained with the use of an
Air Restrictor on the remaining nipple
(air relief) of the JET Tronics valves. A
restrictor on the output will slow the
EXIT of air from the circuit. Robart
offers Air Restrictors: P/N ROB189
DO NOT LIMIT the air pressure, speed or volume on ANY INPUT to gear or door cylinders.
This will compromise the reliable operation of retract circuits under reduced air supply pressures
and increased flight loads and. NOTE: It is highly recommended you DO NOT limit exit air
pressure on the Mains Valve – only the doors
100% air pressure to the Mains. Due to the weight of the gear and wheels, 'slow up' will be
naturally occurring. AFTER several flights, you may choose to limit Main retract air exit to slow
the retract circuits, but this could risk reliable, positive, repeatable, operation.
www.carf-models.com
• 21 clicks = 80%
• 23 clicks = 85%
SAFETY OVER SCALE
BETTER to apply
89
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