RC Transmitter mod

I mentioned in a previous post, Proportional pan servo, about changing the transmitter control sticks for dial pots or variable resistors.

That meant I could set up the rig so the camera orientation directly related to the position of the pan and tilt controls. You always know where the camera is pointing by looking at the dials.











This video shows how it was done.

It was surprisingly easy with all the components unplugging and plugging back in. I just needed to cut the plugs off unused levers to reuse on the pots. This RC set is 4ch and I only needed 2ch.

I first measured the resistance of the lever pots and got values ranging from 1k to 2k. Folks on the KAP Forum had used 5k successfully so I bought 5k and 1k. Both worked and gave the same range of servo movement.





I got sick of trying to juggle the reel and transmitter at the same time so decided it would be better to move the control knobs off the transmitter to a hand held extension cord. Now the transmitter stays in my pack and the controls dangle over my shoulder within easy reach.

This was easy, really just adding longer wires to the pots.

KAP rigs - RC Canon S100

The Lumix LX3, a superior compact camera, was soon to be reclaimed by it's rightful owner (wife) so it was time to find a replacement.

Using the camera feature search on DPReview I looked for any compacts with 24mm wide zoom and intervalometer to replace the shutter servo. The only camera currently available fitting the search was the Lumix LX7 weighing 298g, a little too heavy for light weight KAP.

An alternative option was to add intervalometer function to a Canon compact using the CHDK firmware hack. The Canon S100 looked interesting, with GPS, only weighing 190g and A$100 less than the Lumix.

DWI  had the S100 for A$280 which was fine by me. I tend to think of KAP cameras, like underwater cameras, as expensive disposables.

Canon Powershot S100 RC rig - 460g

I am finally happy with this setup.
- CHDK/SDM intervalometer (explanation coming soon)
- Proportional pan and tilt using Turnigy 380MG mini servos
- Brooxes compact picavet and tripod bolt from the KAP shop
- Fibreglass face plant protection bar
- Safety leashes on the camera and tripod bolt

Proportional pan servo

A more logical method for pan is to use a larger gear on an unaltered servo with a smaller gear on the pan bolt. With the correct ratio (5:2 in my case) you can achieve +/- 180º rotation (=360º)  from a +/- 45º servo.

Also by changing the transmitter pan lever for a rotating pot or variable resistor (more about that later) you can make the rig pan position match the transmitter pan knob position.

This means you always know which direction the camera is pointing by looking at the transmitter pan knob.

A note of caution. Small movements of the pan knob give large movements of the rig. You need to be prepared for a sudden rotation of the rig when it is turned on. It's a good idea to turn it on to align the rig before hanging from the kite line and with no tension on the picavet. This way the picavet will spin on start up rather than the rig.