Six position switch modification for use with ArduPilot or anything else.


This should also apply to the new 9XR as well as the Turnigy 9X. Even any radio that has a knob on it.

Credits to Paul Mather and Max Levine who wrote the original articles on this mod. You can see Pauls article on DIYDrones here.

What I have done here is not different at all, all I have done is is taken a few more photos so hopefully it is a little clearer.


Difficulty: 

Easy. Basic soldering and knob knowledge required.


Stuff list:

  • 6 Position Switch (knob). You can get them from ebay for about $8. Simply google "SRRN162 alps".
  • Resistors: 1x68Ω, 6x1.5KΩ and 1x750Ω
  • Your radio.
  • Soldering iron and tools.


Instructions:

First, up open your radio. You can replace any knob on your radio you like. I chose the one on the front as the others are now used for my PS2 Joystick mod. Remove the existing pot and de-solder the wires, You should have Black, Brown and Red wires. Being GND, signal and 5V respectively. If your colours are different test them to be sure.

turnigy 9x

Remove the offending plastic by bending back and forth with a pair of pliers.

turnigy 9x 9xr 6 position switch knob

Now remove the knob on your new knob. I used a pair of side cutters, be careful you dont want the knob hitting you in the eye.

turnigy 9x 9xr 6 position switch knob

Sorry lots of knob references here.

Remove the mounting bolt and test fit it. It will require a bit of pushing to get the thread through the hole but it should fit without drilling.

turnigy 9x 9xr 6 position switch knob

Take it back out and start attaching the resistors. The end result should look like this.

turnigy 9x 9xr 6 position switch knob

Also refer back to this image for the final wiring.

turnigy 9x 9xr 6 position switch knob

I chose to thread all the resistors through first before I did any soldering.

If you have a 768Ω resistor great, if not you will need two resistors for the ground side.

turnigy 9x 9xr 6 position switch knob

This is the five 1.5KΩ resistors soldered in place. Be careful that the leads do not short on the body of the switch.

turnigy 9x 9xr 6 position switch mod knob

A little trimming of leads and we are ready to put the switch in. I plan to use the unused terminals to hook up some LEDs so indicate what mode I am in.

turnigy 9x 9xr 6 position switch knob

Again refer above for the annotated image which shows what goes where. 
Remember you can click any of these images to get a closer look.

turnigy 9x 9xr 6 position switch knob

I added some heat-shrink over the resistors and wire to make it strong and prevent shorts.

turnigy 9x 9xr 6 position switch knob

Screw the nut on and all you need to do now is find a knob for your knob.

turnigy 9x 9xr 6 position switch knob

I could only find this great big knob in my box. Search around there are knobs all over the place.

turnigy 9x 9xr 6 position switch knob

Not strictly necessary, but you may prefer to calibrate your new knob before use. I certainly dont like my knob going off in the wrong position. End result should be six positions that will give fairly evenly spaced PWM signals.

If you are using ArduPilot you can now set this up for use in the Mission Planner software. I have some other uses in mind such as a camera switcher for my FPV setup.

Happy hacking.