Building a Loc-Line arm for the Sunpak G-Flash strobe

[SeaYoda]

This is the "How I did it" tutorial on a Loc-Line arm for the Sunpak strobe. Each step will be in a separate post with pictures appropriate for that step. Loc-Line size is 3/4". Many parts will not be specifically identified (screw sizes, washer sizes etc.) - you can substitute what you have locally.

Step one: Transition from handle to arm

The supplied handle / tray is what the Loc-Line arm is attached to. I used a small "L" bracket to transition from handle to arm. Lock washers are important in all connections and rubber washers are needed to keep some points from slipping. The "L" is attached to the part of the handle where the strobe would normally be placed. The other end of the "L" is where the arm begins. Be sure to use a rubber washer between the "L" and the first segment of the arm. The first segment is a fixed mount (base segment). Above that are the regular segments, as many as you want for length. The first of these regular segments needs to have two small holes drilled into it for drainage. The holes should be approximately across from each other.

 

[SeaYoda]

Step Two: Transition from arm to strobe

At the end of the regular segments you may attach the strobe directly or, as will be covered in step three, attach a focus light. Step two will describe the strobe attachment to either of these options.

I used a modified shield system elbow segment to attach the strobe to the arm segments. The elbow comes with a short screw that needs to be replaced with one that is long enough to reach through the strobe's two attachment forks. The elbow's two plastic parts have "teeth" that need to be cut off (box cutter or similar tool will work) and sanded flat. I used plastic washers between the strobe attachment forks to keep them from squeezing in and breaking as the assembly is tightened, the screw goes through the middle of the washers. I used rubber washers on the outsides of the forks (inside the plastic elbow parts) to prevent slipping. I used washers on the "disk" end of the elbow to give it more strength for tightening.

 

[alcina]

SeaYoda -

Thanks for taking the time to post this! I'm sure it will be helpful to many

 

[SeaYoda]

Step three: Optional focus light assembly

I use a mini Q40 as my focus light. To add the focus light, a "Y" segment is added just below the elbow segment in step two. To the open end of the "Y" segment is attached a double female segment. Attached to the double female segment is a fixed mount (base) segment to which a hose clamp is attached. Be sure to use a rubber washer between the clamp and fixed mount segment to decrease the ability of the clamp to turn. The clamp is threaded through the Q40's handle and tightened.

 

[SeaYoda]

SeaYoda -

Thanks for taking the time to post this! I'm sure it will be helpful to many

You are welcome.

BTW, I am not affiliated with Sunpak, UK, Loc-Line, or any other product listed above. I receive nothing from these companies and therefore I charge accordingly. All instructions above are intended for private use, no warranty implied. Use of the above instructions indicates that you will hold me harmless if something should happen to your particular set-up as a result of using said instructions. YMMV.

 

[herman]

Nice job Yoda. I made a similar one to extend my Inon arm and D-180. I find it a little loose and floppy above water but underwater it works great. Instead of the thumb screws you used, I opted for SS wing nuts and standard bolts.
I would add that all the hardware needs to be either stainless or aluminum. Otherwise it's going to rust very quickly, esp in salt water.

 

[midwestdvr]

Thanks for the post. Might have to incorporate your system into mine. One question, do you have to turn off your focus light before taking the pic?

 

[SeaYoda]

... do you have to turn off your focus light before taking the pic?

No, it was not bright enough to show up in my test pictures. The strobe seems powerful enough to wipe out any hot spot from the light. Maybe at a lower power setting on the strobe, closer subject, or different camera settings it would be visible but not the way I took my test shots.

Here are the two tests I've done so far:

http://www.scubaboard.com/showpost.php?p=1569478&postcount=52

http://www.scubaboard.com/showpost.php?p=1569552&postcount=55

 

[SeaYoda]

After using the arm system above for 3 days and six dives, one of which the strobe was kicked and bumped by clumsy fellow snorkelers, some fine tuning of the attachment section will be in order. The arm twisted more than it should have and ate up the rubber washer which in turn made the arm turn even more.

I'll post my solution when I decide what works.

 

[SeaYoda]

I have experimented with the arm setup a little and here is what is working so far:

Change #1
The "L" bracket attachment had to go because it bent too easily with light bumping. I attached the base segment of the loc-line arm directly to the Sunpak handle as pictured here: