7 replies to this topic

[uwxplorer]

This is a multi-part post.

Inspired by this thread by wydeangle, I decided to solve one of the problems I have, which is that the Big Blue VL1300 lights, as nice as they are for video, are negatively buoyant and therefore tend to make light adjustment (especially forward) quite a challenge for my arms. Just as a reminder, here is a photo of my current setup.

I purchased exactly the kind of foam he recommended ($28.67, tax & shipping included) and received it the next day. Based on his calculations (which I confirm!) I shot for 20 square inches (~ 4.5 x 4.5). Unfortunately, the way the VL1300 is designed does not allow putting two pieces, let's say 3x7" each, on both sides of the light, as he did for his Hartenberg light. One of the main reason is that you need to have access to 3 or 4 locations:
- 1" ball to attach it to an arm (and have some flexibility to tighten or losen it)
- intensity control ring
- front part (to disassemble the light to recharge it)
- rear part (to open it up it you need to change the battery - which should never happen)
In addition, the body of the light has a non trivial shape (it is slightly narrower in the center), so for stability, it it necessary to carve the foam somewhat.
I decided to try out a 3 part float which would cover only part of the body. The best I could come up was three identical 2x3 5/16" parts.
I'll describe how I made them in the next post.
Let me add that after I tested the floats, I realized that the light was head heavy (and not quite neutral), so I had to design another part which I slid around the front part of the light (I will describe this in a third post).

The final result looks like this:

[uwxplorer]

Design of the main body floats.

I cut out 3 identical parts from one corner of the 1x10x12" foam block using a hack saw:

The line 11/16 from the top defines where the block will be slightly carved to account for the wider diameter of the head (The blocks will stop just before the rear part of the body widens):

On the outer part, I defined two 3/16 wide shallow grooves for the two cables ties which will hold the foam blocks together. I used 24" long cable ties ($5 for 10 at Home Depot). I carved the edges of the grooves using a knife. This foam is very easy to work with.
The assembled parts look like this:




As you can see, there is good access to all the parts I mentioned in the introduction.
The 3 blocks rotate as a whole around the light (over ~ 30 degrees) if needed, but they are not freely roaming around (the cable ties are tightened).
Now as I said, the light is still front heavy in this configuration (and is still not neutral, at least in fresh water).
So I went on and designed a front float as described in the next post.

[uwxplorer]

Design of the front float.

I did not have much choice for the front float, since I needed to be able to unscrew the light head (to recharge it), and as far as possible still be able to slide in the red filter I use as a protection for the lens when not diving. After some sighs at the idea of having to cut out such a part, I went ahead and decided for a 4x4" square slid around the head:

I just used followed the contour of the head to draw those circles, and yes, I know, they are not centered...
Anyhow, after some efforts with the knife (again this is a relatively easy job, although you need to be careful not to cut yourself) and a hack saw blade to get smooth edges, I manage to force fit the head part and use the float to screw it back on the main body. A quick test showed that the light thus equipped was now too buoyant (in fresh water) so I sawed of the corners to get an octagon:



As shown in the first post, the filter fits nicely in the front (I forgot to mention that I had to remove one of the external O-ring, which play no obvious role, except for the first one, which helps holding the filter in place).
I still need to test this contraption in salt water and possibly adjust the size of the front float, but since my Fathom lens makes the housing negatively buoyant, that may not be necessary.

Edited by uwxplorer, 08 October 2011 - 04:57 PM.

[peterbkk]

You should have just bought the L&M Solas and saved yourself a lot of trouble...

[uwxplorer]

You should have just bought the L&M Solas and saved yourself a lot of trouble...

I tried, but this was too early in the production run and I could not put my hand on a pair...

[wydeangle]

Uwxplorer,

Well done!

If you don't mind a small suggestion, I'd recommend putting the zip tie buckles at a corner so they don't present a snag point.

I predict you'll enjoy the results!

Peterbkk,

Evidently you didn't look at my original writeup - the Solas are enough negative they require some compensation.

Tom

[uwxplorer]

If you don't mind a small suggestion, I'd recommend putting the zip tie buckles at a corner so they don't present a snag point.

Good point. I actually cut them shorter. I don't think they will be more of an annoyance than the lights themselves, which I have to watch carefully when navigating through the kelp forest...

[uwxplorer]

Late update on this system: I eventually discarded the ring-shaped parts I had so painstakingly carved out, as my rig was too buoyant with them. Other than that, this works like a charm.