Mounting Bailout Bottle to Draeger Shell

MDDiver

Besides using the bag has anyone found another way to mount bottles successfully to the Draeger Dolphin shell?

4ster

This solution requires drilling 4 holes in the shell:
New Products

This is a special flat base bracket that mates well to the relatively flat sides of the Dolphin shell.

I was worried about cracking the shell so I used nylon fender washers (larger outside diameter than standard washers) to spread the load where the bolts go through to screw into the bracket. I also used a flattish round headed phillips screw on the inside so that there would be no sharp edges against the counter lungs.

__________________
Steve
"My problem is that I have trouble reconciling my gross habits with my net income." Errol Flynn

camerone

Others work well, too - Reef Scuba makes the "Pony Tamer" which works great, if you drill the female side of it with a countersink bit and then bolt it to the Drager shell. I used this for an argon bottle for a while, and had much success.

Also, the _really_ cheap metal snap-mounts work really well, too. That place costs too much - they should be around $35 - $40 if you look hard enough. Again, they're not really curved enough to matter, and you just drill through the Dolphin case with a couple of SS screws; use a nyloc on the inside to hold things secure. There's more than enough clearance between the two halves to clear a screw head just fine if you look carefully when you drill for proper placement. I found one at a flea market for around $15 and used it for two years on my Dolphin to hold a 19cf on the other side from the argon bottle.

The shell is actually set up for just a pair of straps (sort of pseudo-cam-bands) through the slots in the side, by the way. The very early Atlantis units didn't come with a bag...they had straps, instead, with a cheesy rubber pad that was supposed to tension a little, and the usual fastex buckles.

In ANY case, the shell on the Drager is too weak to really support any of the above, inclusive of the stock "straps", without some reinforcement...unless you happen to really enjoy solvent welding the cracks back together again. The previous suggestion of large fender washers is a very good idea, or, you can do what I did: I machined (er, laser cut) a piece of 1/4" plastic with two holes in it for the screws to go through, and when I bolted things to the shell, I backed it on the inside with the extra inch thick piece of plastic. Appropriate sheet metal would also work and be thinner. Turns out there's just a bit over 1/2" spare, side to side, inside the shell, so it's not a problem to fit the scrubber in.

You can, for a while, get away without backing the hard mounts, but sooner or later, you _will_ be out there with solvent weld. I don't think I would risk clamping down cam-bands without some sort of reinforcement, as the pressure would probably crack the plastic immediately.

Obviously, depending on your mechanical skill level and desire, there are lots of other cooler designs; lately, I've been pondering some myself, too. I'm thinking of an mCCR conversion, as it seems a shame to leave it sitting in the garage gathering dust (which it's been doing for the last three years).

4ster

If on deeper dives, I dive with 2 13cf ponies. I have an early Dolphin that had the wimpy straps that didn't work, instead of the pony bag. Since it is only once in a while I didn't go to the trouble of mounting a second bracket on the left hand side but instead use the straps through the shell method. The key was to find a wide elastic strap with a tacky rubber surface that does not let the cylinder slip. It works surprisingly well.

__________________
Steve
"My problem is that I have trouble reconciling my gross habits with my net income." Errol Flynn

Divein

I have attached G snaps to each side of the shell with the male part bolted through the shell and the female attached to the cylinder. The male part did require an extra washer on one bolt to ensure that the cylinder was vertical when engaged.

tamorgen

Did you have to drill with the G-Snaps? I've been considering this, but I don't want to do any damage to the shell, should I want to sell it in the future.

Divein

Yes. Drilled through the g snap and used a hex bolt with a large washer between the g snap and the shell. Have to be carefull with the size of the nut on the inside of the shell as it could make putting the scrubber in difficult. I will try and post some pics tomorrow.

firemandiver

I've found a really good way to mount them. I bought a pair of Tiger mounts from another Rebreather World member and they're terriffic. I don't have the link handy, but I believe it's tigergear.com A quick Google search will get you there. They are paired machined aluminum brackets that slide together and lock in with a quick pin. The fit is really nice. No wobbly bag! You could simply use fender washers as a backer, or get a couple of pieces of 1/8 aluminum plate 3X5 and match up the four mounting holes and then you have a rock solid mount. If you take a look at my pevious post with my homebuild you can see exactly what they look like installed. Hope this helps. PM me with any questions. FD

Divein

Pics of the G snap fitting.

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tamorgen

Divein,
Did you get the mini G-Snap system, or the standard size. The reason I ask is that you have holes in it obviously for the nuts, and the picture on Oxycheq's web site for the standard size (about 11" long) does not have holes. I did a google search and found the mini G-Snap system (about 6" long), and it has holes in the mount to mount on rebreathers. It's also only about $35, as opposed to $90 for the regular mount.