The View Up Here

Random scribblings about kites, photography, machining, and anything else

Your Basic DSLR KAP Rig

Posted by Tom Benedict on 13/08/2011

Once the order from Brooxes came in, modifying my A650IS HoVer rig to take the Canon T2i took very little time.

T2i KAP Rig - Head On!

I still haven’t got it airborne, but I plan to this coming weekend. Meanwhile here’s the low-down:

My A650IS HoVer rig had a flying weight right around 945g. The all-up flying weight on the T2i rig (which does not have a HoVer axis) with the 18-55mm kit lens is 1129g, or just under 200g heavier. Just for comfort’s sake I looked at Cris Benton’s Flickr stream  and checked the weight on his Canon DSLR rig. He’s got a HoVer axis on his, which I don’t, but his is built using carbon fiber and wood, which is lighter construction than my aluminum rig. His overall weight came in at 1410g. Of even more comfort was his comment that when he built it, it was double the weight of any rig he’d flown, yet the weight really didn’t turn out to be a problem in practice. Just another KAP rig. I still plan to test this weight using a water bottle dummy weight, but it’s encouraging.

To make the T2i DSLR rig happen I made the following changes to my venerable A650 rig:

First, the tilt frame with its horizontal/vertical plan rotation axis (HoVer axis in KAP parlance) came out, and a Brooxes Utility Frame with the wide shelf attachment I mentioned in my earlier post took its place. The balance was dead nuts on, first try. Yaaay! (Love it when things work first time.)

Next, the Futaba S3003 servo I’d been using for tilt came out, and a Hitec HS-645MG servo took its place. I mentioned this in my previous post, and my reasons for doing it. I’m glad to say this also worked first time. No oscillation, no wobblies, and with the clean balance on the new tilt frame it’s not drawing a lot of current.

I changed out the GentLED-CHDK cable that triggered the A650IS camera with a GentLED-Focus cable with the 2.5mm plug to match the cable release on the T2i (and a whole host of other DSLR cameras, by the way.) Unfortunately it came with a straight 2.5mm plug instead of the right-angle plug I’d seen on this unit the one other time I worked with one. So I need to pick up a 90 degree adapter from Radio Shack. Minor problem, easily solved.

I still need to get a small diameter, wide rubber band. You get these on bundles of broccoli or asparagus at the grocery store. I used to keep a stash of them when I was doing 35mm film photography actively. They’re great for locking a zoom lens at a particular position, or locking a focus ring so it can’t drift. I’d like to run the kit lens at 18mm and lock the zoom. Nothing beats the band!

Here are some other photos of the rig:

T2i KAP Rig - Front

T2i KAP Rig - Back

T2i KAP Rig - Bottom Detail

The only real caution I saw is that unless the camera is horizontal to the ground, the lens can strike the ground before the legs do. Not a huge deal, but certainly something to be aware of.

T2i KAP Rig - Lens Interference

So now the plan is to fly tonight and tomorrow night using a dummy weight tuned to the 1130g of this new rig and camera, and to go out Saturday to find some kind wind and a photogenic subject so I can finally get it off the ground.

Things get even better! As I was writing this, I got word back from Getty Images. I’ve been given a list of things they’d like to see from Hawaii, most of which lend themselves well to this new rig and to its sister rig that I’m building for my 24′ pole. Time to get this thing airborne!

– Tom

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One Response to “Your Basic DSLR KAP Rig”

  1. Bill Blake said

    Great set up Tom, I look forward to high res photos!

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