Here we are adding an extra joystick to our 9X that we can control with a spare finger at the back of the transmitter.
Some ideas for what it could be used for.
Pan and tilt for an FPV camera.
Thrust vectoring control.
Crow brakes and reflex. (with some mixing)
A gun turret.
Difficulty: Easy. Basic soldering and drilling skills required.
A very quick video demo and explanation.
Read on below for the details on the mod:
Here we have the PS2 thumbstick. It includes two 5k pots and a push button switch.
I bought this one from Ebay for a couple of dollars. Entire controllers can also be had for around $5. Just search for 'PS2 joystick' or 'PS2 controller' The same method could also be used for other small analog joysticks.
This is where I have chosen to mount the thumbstick.
We are going to be working with the back of the case. First thing to do is to remove the circuit board, switches, pots and dc socket and put it aside. No need to de-solder anything just yet. Also remove the handle while you are at it. In hindsight I would probably place it 5mm further towards the top of the 9x.
Pilot holes first to make sure they are in the right spot.
Once drilled fully we can make marks for the other pins.
I use my favorite dental tool to marks the spots.
All drilled out.
Fits flush now.
Not quite enough clearance to solder.
Some dremel work and we have room to solder.
Rough up the underside so the hot glue takes better.
A small dab of hot glue and press it in place. It would be nice to recess this more into the body, however there is not much clearance inside. To make the installation neater you could cut away part of the controller and stick it over the joystick but this will not add any strength or functionality.
You can see above that I have relocated the handle so that the PS2 stick does not rest on anything when placed down.
Simply remove the handle and drill new holes as shown.
Dip switches glued together. It is important to have the 'ON' sides facing each other. That way we can make it into a DPDT switch. Some of the photos below I had it the wrong way around.
You could also use any commercially made DPDT (Dual Pole Dual Terminal) switch. Drill a hole and place it elsewhere on the unit. I had these on hand and wanted something out of the way that would not get accidentally switched while in flight.
I used part of the old battery case to join the switches.
Marked and ready to cut. Yes dirty finger nails again, I have been gardening.
I mucked up the hole on the left but it will still work.
Cut off and glued in place. However it is easier to do this after the switches have been glued in place. Without this piece of plastic we run the risk of switching both sides to ON at the same time. Not desirable as this will cause a short circut from 5v to ground. If you are really paranoid I would use a purpose built DPDT switch.
Roughing up our mounting spot.
And the switches.
Glued in place.
And with the switch cover on.
Time for the wiring, John asked me for a curcuit diagram. It should help to get your head around what I am trying to do.
Look at the pictures below to see where the board connections go. If you cannot understand this don't worry just do exactly as I have done below.
Time for some soldering, I used kynar wire but any type will do. The right two pins are connected to the center pins on the PS2 stick pots.
To complete the DPDT switch we need to solder these two pins together. The circuit board will be press flat against this spot so the pins need to be bent flat. Also cut away a spot for the wires to get out at the top.
Pins on the left go to the center pole of the original pots. Center pins will be connected to the board.
The wire lengths need to be roughly so. Dab some hot glue at the top of the switches to hold the wires in place. We are now ready to replace our board.
Before we do on the left side cut the top wire. In this case it was yellow but the color may differ.
On the right side cut the middle wire, here it was red.
Board back in place and pots and switches put back in. Remove the cut wires from the center pins of the pots and solder the new ones in place. The other two wires go to the pads on the back of the board as show.
Next step is to solder 5v and GND to the PS2 pots.
We also need ground on the bottom pin of the push switch.
Finally the wire for the top of the push switch connected to the second pad shown here.
And the other end here.
All done, some final dabs of hot glue to hold the wires in place and you can re-assemble your 9x.
Last step is to re-calibrate with the PS2 stick turned on. In the mixer the pot is P1 and P2 and the switch is THR. To use the thumb switch the THR CUT switch needs to be in the up position.
All done. You are ready to control pan/tilt, a gun turret, crow brakes or whatever you can imagine.