Kite Aerial Photography: Controller
Since attending KAPiCA in Novermber 2002, I’ve been itching to repackage my radio transmitter. I immediately saw the advantages when I observed many of my European counterparts not having to juggle their kite and transmitter at the same time. I chose the HiTec Laser 4 Transmitter because of its simplicity and its relatively low cost. One important thing to note is that the Feather Micro Receiver that came packaged with the radio does not provide adequate range. HiTec claims up to 1000 ft. but I found it to be much less than that—as little as 100 ft.—in practice.
Now I can strap the transmitter to my waist, freeing both hands to concentrate on flying the kite. In the past, I was forced to drop the controller on the ground (freeing my second hand) to quickly haul in the kite when winds subside. Sometimes this was not enough, and I needed to run into the wind to keep the kite aloft until the wind stabilized. However, If I set the controller down first, it was often difficult to get back to it while keeping the kite up in less than ideal wind conditions.
Another advantage of repackaging a radio transmitter for KAP is that the controls can be made more intuitive: a flip switch for HoVer, a slider for tilt that doesn’t spring back to its center point, and a push button for the shutter. The panning channel can be a rotating potentiometer or a two-position toggle switch if the pan servo has been modified for continuous, 360° rotation. My rig uses a modified servo, so I chose a toggle switch.
Besides being able to strap the transmitter to my waist, the most important modification was to have two push button switches for controlling the camera’s shutter (in conjunction with the twin Schieppati Switch onboard my rig). One, a locking switch, will pre-focus the camera enabling me to press the second switch to fire the shutter instantaneously. This can be important for capturing ephemeral moments, and I’ve been frustrated on occasion not having this ability. Thanks to a custom circuit diagram that Peter Bults designed, I can still use a single pushbutton switch to fire the camera independently of the locking push button when exact timing is not important.
Schematics of the circuits I used (.pdf file)