Backmount inspo dived.

johnmaneely · 11th June 2007, 23:13

This is some pics of my BMCL inspo that I have been putting together over quite sometime now. Its seen action in a pool, then a 6m lake and then straight onto a 70m cave dive.

The breathing resistance seems pretty good. It seemed on descent that a resistance seemed more noticably than usual. I'm guessing its just that the adv on my inspo was set up pretty stiff by its last owner(he did mention it)and when gaining depth quickly it proved a little uncomfortable. Once at depth with the correct loop volume the resistance seemed fine. I've adjusted the adv and will try it again. Used to use the lung button for dil addition before.

I had a few minor problems along the way. Where to package everything as I wanted it as small as possible for starters. I changed the cylinder valves to give better hose runs and had longer or shorter hoses where needed. Including the mouthpiece ones which ain't cheap. In all its cost me about £400 for all the bits, including a remote O2 add system from John Routley, the case material, the lungs and new hoses, valves.

Had the lungs custom made by chris at hammond drysuits, which came out very well and I'm happy there robust enough to see plenty of service. Had a couple of leaks with lung fittings but got those sorted.

I'm pretty happy with the unit now just need a bit more dive time for it to feel part of me. The trim is very good and I'm horizontal with a 3lb weight on the top of the unit and thats it. I need no weight belt with my membrane suit thanks to the stainless case, but may move on to make an ally case as well. I'll mod the design a little to iron out some niggles and the lighter case will make it easier to transport where I have carry it for a bit. Its pretty darn heavy as a fully built up unit.

Its great to have a clear chest area for stages and get the weight on my back where I want it. This has helped releave the back ache I used to get with the box.
Cheers
John

http://www.rebreatherworld.com/home-...+lung+question

colinicky · 12th June 2007, 07:14

Hi John
Glad to see you got there in the end

Looks like you changed the design of the lungs from the original drawings ? Are they sealed bags or just cases for the inner bags ?
You say you changed the cylinder valves but in the pictures they look standard ?

Be interested to know the weight of the ss box on its own

johnmaneely · 12th June 2007, 18:09

The valves in the pics are the old ones, I hadn't fitted the new ones when I took them. I did this project partly for my college course and needed pics for the write up.

The lungs are just a flat design, it was simple for chris to make and suited the purpose to. Nice and simple. There are no inner bags, the lungs are drysuit membrane material and taped on the inside. There pretty strong. With the o2 addition system stuff and an OPV my lung volume is around 4.5 ltr's with the lungs in the case. Very close to my own. Ideally I could do with another longer bag to bring the volume up a little and give me a spare bag.

The scrubber inlet tube is a bit exposed and needs a guard of some sort. It got some marks during the cave dive and with a heavy whack it could be damaged.

I don't really want to lay the unit on its back either because of the pipes position.

I think the case alone weighs 5 kg, with a stainless plate and 1kg block I'm good to go, no belt which is lovely.

Going to have another dive with it this week hopefully

.

John

colinicky · 12th June 2007, 19:40

Thanks John glad chris sorted you out

tony30 · 12th June 2007, 22:28

Quote: (Originally Posted by johnmaneely)

The valves in the pics are the old ones, I hadn't fitted the new ones when I took them. I did this project partly for my college course and needed pics for the write up.

The lungs are just a flat design, it was simple for chris to make and suited the purpose to. Nice and simple. There are no inner bags, the lungs are drysuit membrane material and taped on the inside. There pretty strong. With the o2 addition system stuff and an OPV my lung volume is around 4.5 ltr's with the lungs in the case. Very close to my own. Ideally I could do with another longer bag to bring the volume up a little and give me a spare bag.

The scrubber inlet tube is a bit exposed and needs a guard of some sort. It got some marks during the cave dive and with a heavy whack it could be damaged.

I don't really want to lay the unit on its back either because of the pipes position.

I think the case alone weighs 5 kg, with a stainless plate and 1kg block I'm good to go, no belt which is lovely.

Going to have another dive with it this week hopefully

.

John

Hi, Can I point out the position of the cells? They all point down when the canister is lying correctly, I think you may be putting cell 1's readings at risk by allowing any moisture to pool on the cell face

, might be fine for a short dive but difficult for any duration or repetetive diving. Hope this is helpful.

johnmaneely · 13th June 2007, 13:20

Not a point I had looked at to closely, thanks Tony. I'll have a closer look the the position of things in the head at this angle.

I did have a slightly lower reading on number 3, think it was a cell prob as they are getting on a bit.
Thanks
John

tony30 · 13th June 2007, 21:53

No worries, let us know how you get on.

12th June 2007, 07:14	#2 (permalink)
colinicky RBW Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Mar 2005 Location: uk Posts: 681	Re: Backmount inspo dived. Hi John Glad to see you got there in the end Looks like you changed the design of the lungs from the original drawings ? Are they sealed bags or just cases for the inner bags ? You say you changed the cylinder valves but in the pictures they look standard ? Be interested to know the weight of the ss box on its own __________________ Colin I trust my rebreather completely , I just don't trust the user onwards & downwards
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12th June 2007, 18:09	#3 (permalink)
johnmaneely New Member Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Classic Kiss Home Build Join Date: Aug 2005 Location: shoreham-by-sea uk Posts: 27	Re: Backmount inspo dived. The valves in the pics are the old ones, I hadn't fitted the new ones when I took them. I did this project partly for my college course and needed pics for the write up. The lungs are just a flat design, it was simple for chris to make and suited the purpose to. Nice and simple. There are no inner bags, the lungs are drysuit membrane material and taped on the inside. There pretty strong. With the o2 addition system stuff and an OPV my lung volume is around 4.5 ltr's with the lungs in the case. Very close to my own. Ideally I could do with another longer bag to bring the volume up a little and give me a spare bag. The scrubber inlet tube is a bit exposed and needs a guard of some sort. It got some marks during the cave dive and with a heavy whack it could be damaged. I don't really want to lay the unit on its back either because of the pipes position. I think the case alone weighs 5 kg, with a stainless plate and 1kg block I'm good to go, no belt which is lovely. Going to have another dive with it this week hopefully . John
(Offline)

12th June 2007, 19:40	#4 (permalink)
colinicky RBW Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Mar 2005 Location: uk Posts: 681	Re: Backmount inspo dived. Thanks John glad chris sorted you out __________________ Colin I trust my rebreather completely , I just don't trust the user onwards & downwards
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12th June 2007, 22:28	#5 (permalink)
tony30 New Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: May 2007 Location: sw Posts: 7	Re: Backmount inspo dived. Quote: (Originally Posted by johnmaneely) The valves in the pics are the old ones, I hadn't fitted the new ones when I took them. I did this project partly for my college course and needed pics for the write up. The lungs are just a flat design, it was simple for chris to make and suited the purpose to. Nice and simple. There are no inner bags, the lungs are drysuit membrane material and taped on the inside. There pretty strong. With the o2 addition system stuff and an OPV my lung volume is around 4.5 ltr's with the lungs in the case. Very close to my own. Ideally I could do with another longer bag to bring the volume up a little and give me a spare bag. The scrubber inlet tube is a bit exposed and needs a guard of some sort. It got some marks during the cave dive and with a heavy whack it could be damaged. I don't really want to lay the unit on its back either because of the pipes position. I think the case alone weighs 5 kg, with a stainless plate and 1kg block I'm good to go, no belt which is lovely. Going to have another dive with it this week hopefully . John Hi, Can I point out the position of the cells? They all point down when the canister is lying correctly, I think you may be putting cell 1's readings at risk by allowing any moisture to pool on the cell face , might be fine for a short dive but difficult for any duration or repetetive diving. Hope this is helpful.
(Offline)

13th June 2007, 13:20	#6 (permalink)
johnmaneely New Member Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Classic Kiss Home Build Join Date: Aug 2005 Location: shoreham-by-sea uk Posts: 27	Re: Backmount inspo dived. Not a point I had looked at to closely, thanks Tony. I'll have a closer look the the position of things in the head at this angle. I did have a slightly lower reading on number 3, think it was a cell prob as they are getting on a bit. Thanks John
(Offline)

13th June 2007, 21:53	#7 (permalink)
tony30 New Member Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: May 2007 Location: sw Posts: 7	Re: Backmount inspo dived. No worries, let us know how you get on.
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