Any butt or top mounting experience...

Padowan

Excuse the title, but it DOES perfectly describe the nature of the question!

I've got my YBOD in it's yellow case, and have up til now been running my suit inflate of a 1.5L Ally bottle mounted on the side on a little Q/R bracket.

I've recently got hold of a steel Dumpy3L cylinder which is a perfect size (when compared to a normal 3L cylinder) that it could be mounted horizontally across the top or bottom of the rig - this will give me more gas that I can also use for bagging up spidge, without wasting bailout gas. Originally I was thinking about making a little cage to mount the cylinder at the bottom of the unit, but being steel, I am thinking that this will muck up my trim, and make me all ass heavy (specially with the weight of a bracket). So I then thought, "what about top mounting", that way, I could probably remove the 4kg weight I have in the pouch on the top.

So mounting on the top means firstly I don't need a cage, I can just bolt a bracket onto the shell and secondly I can probably remove some lead, and replace it with useful gas. It will be quite a lump on the top, but I don't think I'll twat my head on it...

I'll then have a spare 1.5L cylinder which I thought would make a nice redundant O2 source, but where would I put this? If I clipped it to the side, I've got a wider rig again. From purely a size perspective it would make more logical sense to butt mount the Dumpy 3 and top mount the 1.5, but I don't think the trim will be particularly good....

I've seen this,
but I think he's got all ally cylinders on it...

Any comments or experience on top or butt mounting cylinders, before I start drilling and welding up cages...

Thanks.

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jradomski

I'm not sure about the bottom cylinder but the top cylinder is a oms 2l steel made by faber.

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Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Crazyduck

Just out of curiosity have you considered scrapping that plastic case and go to a cage type cover? There is one in the gallery (for the point of discussion)- http://www.rebreatherworld.com/gallery/browseimages.php?c=30&userid=and

That way you mount a second set of tanks vertically between the scrubber and the other tanks?


Andrew

Padowan

I've been thinking about a cage. But the reason I'm not looking at cage is that the tanks are not paired up in similar sizes.

I suppose though that I could get another 1.5L instead of the dumpy 3, then run the 2x 3L tanks with Diluent for the unit, and Air for the suit and spidge, then have the 2x 1.5L tanks both with oxygen in, one plumbed into the solenoid, one into the manual injector. This would make the unit nice and symmetrical, and I'd have as much O2 as now, but with better redundancy.

I like the idea of a cage/box, but the ones I've seen look very deep, and I think this would make you potentially unstable in the water... specially with a set of tanks mounted so far away from your centre of gravity.

I'm thinking around a design at the moment which would be made from cut, then bent plate (stainless or ally) to minimise (I think) manufacturing costs as there'll be little or no welding used...

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Crazyduck

I know what you are saying about the backplate and making your own.

The big problem that my brain is wired for this side of the pond- sorry.

Steam Machines makes a plate, you might want to have a look at that, or

I would give Deep Sea Supply a gander http://deepseasupply.com/.

I think that Custom Divers (your side of the pond) might have something.

I really like the Mark Meadows backplate which is awesome- but its not going to be big enough to mount tanks and goodies too unless…..

Take a look at the Meg setup. If you could come up with a metal center section and bolt that to a metal backplate; then you could band two tanks to the backplate and two tanks around the metal center section. That would give you 4 tanks.

Just a thought.

Regards, Andrew

dive2dive2000

You might also want to look at Joe R's Avatar his frame is pretty stream line. just another thought?

Martin

jradomski

I can fit through anything an OC diver wearing twins can fit through (Originally the profile was a bit higher, and I had tbl with one passage in a set of grottos).. the "thickness" is just about 7 inches.. the rig is very well balanced, better than any rig I have dove, but it did take severaltries to get it right...

PLUS on deep stuuf I can use 7.5l bottles to have extra primary gas without any additional penalty.

This is enrique's original style, the second style has a similiar profile..

My unit is made out of titanium (about 15 lbs) after all the cutting.. at todays prices it would be pohibitive to make... Plus Titaniumis a bitch to weld..

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

Padowan

I've seen Enrique's chassis, and I must say, that the original version (the one you have Joe) I liked the best. In particular, I like the way that you can mount main tanks on the back, and smaller tanks kind of under the armpits, thjis means that the profile of the "pack" on your back is nice and slim and streamlined and the 3rd and 4th tanks are tucked away.

Cost and weight are the 2 biggest considerations, specially if I'm looking at making a one-off!!

Maybe I should just get a Meg, and be done with it!!!

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jradomski

Yeah but the meg doesn't swim as well!
The key reason my rig works well in the water is that the tanks are basically right on your back.. since the meg mounts it to the cannnister its just a few inches further out and you can feel it.. My rig is actually one of a kind.. It was used as the the titanium proto type,plus I had enrique make mods over the last few years.. My unit also uses thicker titanium material than the others he made (most of it is about 50% thicker than necessary), I probably could have saved at least 5 lbs by using the minimums, but at this weight I can dive dry with only adding a few lbs of trim weight at the top.. I also have a heavy base that replaces the wire stand you see on bottom.. It very sturdy but adds about 4.5 lbs.. I only use it in sw (locally) and diving dry..


I don;t dive with the tanks "mounted under arm" that much I actually prefer wearing slings.. what I do usually use those mounts ofr is on on side I put my battery pack for my cannister light, and on the other side I mount my argon bottle..

__________________
Joe Radomski
CCR Trimix Instructor Trainer
ANDI Instructor Trainer Director #10

All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.

trob09

Well, I guess that depends on how you configure your meg. Using G-Snaps, my O2 and Dil bottles are right next to my backplate.

And g-snaps are only slightly less expensive and slightly easier to source than a cutom titanium cage...