KAP - Rig Two

Five Improvements

1. A better camera
2. A better shutter release setup
3. A better Suspension (some may disagree!)
4. A better pan servo
5. A better battery pack.

1 A Better Camera

A 2Megapixels photo needs to be downsized for the web and is fine for small prints, but for larger prints, a higher resolution is required. From the very beginning of my KAP adventure I knew that I would eventually want to put my better camera into the sky. Apart from the higher resolution it has much better facilities, like shutter priority and so on. Rig One needed only minor changes to accomodate my Olympus Camedia C-5000 camera.

2 A Better Shutter Release

I wanted to have a two stage shutter release so that I could operate the shutter in the way it is normallly used. A half pressure on the button allows the camera to focus and determine the correct exposure, then a further press fires the shutter. Those who are into electronics use a micro controler to do this job. If you are of that persuasion see the article on the KAPER E_MAGAZINE site /Articles/2001/ Two Step Trigger. Strictly speaking this is not essential, but the delay between a single press of the button and the opening of the shutter makes it very difficult to time the shot. If the camera is steady this is not a problem, but if it is swinging, you want the photo taken just as the camera reaches the end of the swing and stops, before swinging back the other way. The electronic method does not solve this problem but there is a much simpler (and cheaper) way that does.

Setting Up Your Radio Control For Two Stage Shutter Release

There are three positions for the actuator, fully off, half pressure, and shutter release. The middle one of these is the most critical. It therefore makes sense to concentrate on this function first, and let the other two take care of themselves. I have used the left lever for shutter operation, leaving the right hand lever for pan and tilt, but more on that later.

Mount the servo above the camera.

Make an actuator so that when the arm connected to the servo output is horizontal, the other arm is just touching the shutter button.

Remove the actuator.

Switch on the radio Tx & Rx and push the trim fully down. (Picture I)

Switch on the camera and replace the actuator, selecting a spline on the output shaft so that the shutter button is at the half pressure position. If you cannot achieve this (the button either remains off or fires the shutter), you need to make some fine adjustment. There are two methods. If your radio has adjustable throw volume, it is just a matter of turning the adjuster untill the shutter button is off, then turning it back till it reaches the correct position. If you do not have ATV then you will have to modify the actuator itself.

You should find that:
1. moving the trim fully up will give enough clearance to insert/remove the camera (Picture II).
2. moving the trim fully down puts the shutter button in half pressure.
3. a small dab of the lever fires the shutter (Picture III).

Picture I With trim fully down (top arrow) the shutter button should have reached the half pressure position. The Hitech Focus4 has Adjustable Throw Volume (bottom arrow) which makes this task quite simple.

Picture II With the trim fully up (arrowed), there should be plenty of clearance to insert/ remove the camera. (See photo above)

Picture III a small dab of the control will release the shutter.

3 A Better Suspension System

I had a few tangles and one near miss with the picavet system. When I was putting it away at the end of a session I noticed that the line was badly frayed. I have been unable to source small pullies locally and the rings I was using are obviously not up to the job. I replaced the line but my confidence in the system is shattered. The next outting was on a rather blustery day. Every time the rig swayed violently I could picture my camera heading for terra firma at maximum velocity. I packed up early and headed home.

I now use a simple pendulum that I made from available materials. (A piece of birch plywood, electrical conduit, 4 nuts & threaded bar and a bolt and lock pin).

The top end. Four nuts on a threaded bar are used to lock the conduit in position so that there is a little friction on the ply. This dampens the pendulum movement, otherwise once started it would swing for a long time. Two small karabiners are inserted through holes drilled at the top, several turns of the flying line are wound through each of these to attach the rig.	The picavet cross is replaced by a simple U bracket.	The rig attaches to the botom of the pendulum quickly and simply with a bolt and lock pin..

4 A Better Pan Servo

The dumb servo used on rig 1 worked fine, but since I was in the process of improving the rig, I decided that this too was a candidate for a makeover. I modified a servo by moving the pot outside. This was simply done by cutting a small slot in the servo wall to allow the wires through, and tapeing the pot in place. The stops were removed from the output drive to enable 360° movement.

On startup, the servo can be ajusted for the neutral (stopped) condition. A dab on the stick in either direction pans the rig. I now have a bi-directional pan. If I overshoot the pan, there is no need to 'go round again' as is the case with the dumb servo. I can now reverse the direction of pan to correct the error.

See KAPER E_MAGAZINE for different methods of modifying a servo. Use the site navigator menu:-
    Basics >     Camera Cradle >     360° Servo Convertions.

5 A Better Battery Pack

My old nicad pack had been modified and variously abused over a number of years and needed replaced. I thought carefully about what I should use for the replacement. (This is quite a departure for me. I usually act first and think later.) Part of the problem is a very irratic recharge program. In the days when I used the radio for flying gliders it was very straight forward. Charge overnight on friday. Fly on Saturday till the batteries were nearly flat. KAPping is very different. Charge overnight. Conditions not right so mission aborted. Some time later repeat the process. Great Kapping conditions and free time coincide. Grab the rig. Batteries flat!!

My solution was to use a batterybox. I can insert something more modern than NiCads - NiMh. These do not suffer from battery memory the way NiCads do. I can always buy disposable batteries in an 'emergency' or to extend my Kapping time..