Almost a disaster

I spent most of today working on the new KAP rig and would have finished but for a minor disaster, which led me to spend the last hour of the day reworking. Let me explain...

As I've already mentioned, the camera is a Canon G9 with CHDK loaded, and the shutter will be released by USB, which becomes available under CHDK. I had ordered a GentCHDK connector this week so that I could release the shutter via radio control, which arrived on Friday.

I spent today working on the rig finishing off various parts, like mounting the camera cradle into the upper U and forming the cutout for the USB connector. Having almost finished, I decided to "dry mount" the camera one final time. Up to now, I had mounted the camera into the cradle, and checked that the cradle would comforably fit into the upper U. So now, with the cradle firmly mounted, the camera cushioning fitted, etc. I mounted the camera. Then Tried to fit the USB cable. With the camera oriented straight down, the USB cable fitted snuggly into the connector on the camera, but as I moved the cradle towards horizontal, disaster, as the strain relief on the cable fouled the upper U. How was I going to overcome this one then?

Well after much umming and arring, the solution appeared. If I changed the bends in the upper U from 90 degree to 45 degree, and added another bend about a centimetre down then I would gain some additional width. My biggest concern was that doing this would move the camera to one side, which would significantly alter the balance. But I figured I could overcome this by swapping the battery pack with the receiver. So it was time to strip down the rig and make the necessary bends. Well it is no longer pretty, but it does work, so the upper U now has shoulders!

Time to refit everything. However, having signinficantly increased the gap on one side of the rig, I no longer had a 4mm bolt long enough. this isn't a problem as I have lots of 4mm studso just cut off a legth of that and fit a self locking nut on the end. This done, I remounted the cradle into the upper U. time to check that the clearance was sufficient - it certainly looked plenty. At this point disaster number 2 struck.

Because the locknut is significantly larger than the panhead screw, the camera would no longer fir into the cradle. Now when I say that, the camera actually still has plenty of room, but the hole for the tripod mount no longer lined up with the hole in the cradle. So out came the rats tail and the hole in the frame was widened in one direction until the holes lined up again. With the camer fitted I fitted the USB cable and it now just fits snuggly. So finally, time to refit the pan servo and axle box.

Well that was time up for today, so next weekend, I need to modify the electronics and mount the battery. Unfortunately the battery connector won't now reach the switch, so I'll have to figure out a way of extending the cable run, which will probably involve robbing a cable from somewhere else!

Hopefully we'll finish next weekend and be ready for testing. Not often I ask for bad weather, but on this occasion I'm willing to make an exception.

More progress on the new rig

Another hour or so work this afternoon on the new KAP rig. Today, work centred on forming the lower U.

For those not familiar with the terms, the upper U is an inverted U made out of aluminium strip in this case. The upper U is suspended by an axle at the center of gravity from the kite line. Gears and a modified servo are used to allow the rig to rotate continuously around the axle, giving the rig a pan capability. The lower U is again made from aluminium strip in this case, and sits within the upper U. It is not inverted and incorporated a hole through which a tripod bolt can be screwed into the camera's tripod mount holding the camer in place. The lower U is fixed via an axle to the upper U. At one end the axle is formed by a servo, giving tilt capability. At the other the axle is allowed to rotate freely within the upper U.

Well today the strip for the lower U was cut out of the aluminium stock. All was going well until my nibbler gave up the ghost!, so rather than spend time tryuing to fix the problem, and as its work was largely done, I resorted to a junior hacksaw to finish the job.. With the strip cut and cleaned, holes were drilled to take the axle and camera fittings, and cuts made to allow a lip to be formed to add rigidity. Then the strip was bent to shape and the lips formed. Finally a trial fitting of the camera took place, just to be sure that it would all fit together nicely. Fortunately it worked!

So there is now lots of finishing to do, cleaning up rough edges, knocking off sharp corners, adding all of the electronics, fitting everything together, finishing off the picavet cross, etc., etc. But with a bit of luck, if I get some good time next weekend, I think I should have the servos fitted, the rig parts assembled and tested. I just need to source a Lipo battery, a battery saver, some boxes and make a voltage regulator and sort out some switches and I'll be done!

Progress on new rig

Well I finally got the chance today to do some work on my new KAP rig. So far I have cut out and shaped the top U and cut out the holes for the pan and tilt servos, drilled various holes for fixing the servos and for the axle for the lower U. Looking good. It will be interesting to see the all-up weight once everything has been fitted.

Little progress

Christmas and new year saw me battling against the combined armies of my wife and manflu, so I've made precious little progress to date. About the only thing I have achieved is to successfully download and instal CHDK onto my G9 camera. Being a complete CHDK virgin, I will probably spend a little time palying with the settings.