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.