DIY Strobe Arm

[Tommy2tone_1999]

I have an old Hanimex 35mm, and an Ikelite Substrobe S from the 80s. Well after fighting with that dinosaur in the Keys last year, I decided to go digital. I bought a second-hand Canon A570 IS and a matching housing from Canon - They marked down several of their housings really cheap around Memorial Day. I added CHDK to increase the capabilities, but I also wanted to incorporate the old Substrobe S. To do this I would need a flash arm. I like to tinker a bit so I thought I would make one myself based on some of the designs I've found online. Here is what I ended up with.

 

[Tommy2tone_1999]

Here are the build pics.

I cut the tray out of a piece of aluminum flat bar. To bend the aluminum more easily, you need to anneal (soften) it buy holding it over a flame (propane torch, gas stove top), and let it cool on its own (no quenching).
The cushion was made from a sheet of Fun Foam purchased at a local crafts store.
I went to Grainger Industrial supplies and purchased a Loc-Line Hose set fro less than $13
All screws, washers, and nuts are stainless steel.
The handle is made from PVC pipe and a wooden dowel.

 

[Tommy2tone_1999]

Continued...

I drilled the center out on my drill press
Then I ran the lag screw through the hole and tightened it down with the nut and washers.
Next I coated the dowel in marine epoxy.
The PVC pipe was a tad too small to screw the Loc-Line ball joint in place, so I reamed it out a tiny bit with my Dremel, coated the thread with epoxy and screwed it down tight.
After this I filled the void space top and bottom with marine epoxy.

 

[Tommy2tone_1999]

Even more...

I cut the top piece to attach the strobe from the same flat bar that I cut the tray from and shaped it on my grinder. I also tied a cord loop to secure a cord to in case the hose separated underwater.
I then tied another loop and epoxied it into the ball joint hole.
The top pieces were also epoxied in place.
I then ran a cord through the loc-line hose.
Holes were drilled at the bottom and top of the hose to allow the interal space of the hose to equalize.
I then snapped the hose together, and attached the strobe.
I bought some surveyors colored cord and wrapped the pvc handle with it using continuous half-hitch knots to give it a nautical look. I secured the cord with a little superglue here and there.
The weight of the strobe is a bit heavy, and causes the arm to collapse a little, so I may insert a small length of plastic tubing inside the hose to lend some rigidity.

 

[gert7to3]

Very nice write-up on your project. Remember the weight of the strobe will be neutralized, somewhat, in the water. It probably won't cause the loc line to sag when you're using the strobe.

 

[Tommy2tone_1999]

I saw your build pics too. Great work. Nice use of plumbing. Thanks for the advice on the Loc-Line.