ACTION ELECTRONICS P105 Manual

P105
SINGLE STICK STEAM/WATERJET REVERSER
Throttle stick
forward
Throttle stick
back
P105 is a microprocessor-based unit which connects to the throttle channel of your radio. It has two outputs for
controlling either a model steam engine steam regulator and reversing valves via two servos, or an electrically
driven water-jet via a speed controller and a reversing bucket servo.
Open the throttle slightly in either direction and the reversing servo 'snaps' instantly from one end of its travel
to the other, to operate either the reversing valve lever of a steam engine or the reverse-thrust bucket of a
water-jet. At the same time the engine speed will increase gradually with the stick movement, irrespective of
whether forward or reverse has been selected. This makes the model as easy to operate as a conventional
forward-and reverse electrically powered model - push the stick for forward and pull it back for reverse. You
don't need a third channel to change the model's direction from ahead to astern.
P105 can be used with a second servo instead of an ESC to control the throttle of a model with a water-jet
powered by an I/C engine. You can also use it to operate brushless electronic speed controllers. We strongly
recommend that you fit a spring return lever to the throttle stick of your radio. This makes it very easy to find
the "stop" position you just let go of the stick. We do NOT recommend a ratchet-type stick mechanism -
because, of course, the stick needs to be at its centre position simply so that you can signal "reverse" to the
P105 by pulling back on the stick.
Installation
The unit is supplied fully built with a custom 3D printed ABS enclosure. There are two sets of pin headers,
labelled R (for reversing servo) & T (for throttle) these will accept standard Futaba or JR/Hitec style connectors.
The case is in 2 parts, which are designed to be a tight clip-together fit. Do not try to open the case, you will most
likely damage it. Fix the P105 to the inside of the model in a suitable position, avoiding long extension leads and
making sure it is clear of the bottom of the hull in case of any water ingress. A good idea is to use self-adhesive
Velcro for this job see Component-Shop website (www.componentshop.co.uk) -
The P105 will work with any receiver voltage from 4.8V to 12V
C Action R/C Electronics
www.action-electronics.co.uk
Reversing servo (steam engine reverse lever
Has only two positions, as shown in diagrams below
Steam regulator servo or electronic speed controller
Case size 53mm x 42 mm x
01248 719353
or waterjet thrust bucket)
Moves proportionally with throttle stick
11 mm (approx).
Page 1
Reversing
servo full
forward
position
Increase
motor speed
Reversing
servo full
reverse
position
Increase
motor speed
Original Drawing by Dave Milbourn
updated 2024 by I a in Lewis