How to configure twin 7's?

[nigel]

Ive got the sds latching on both sets of twins and it saves a lot of time and messing about best bit of kit Ive used in a long time.


nigel

[Justin Owen]

Digs, have emailed you back... Will email you again tomorrow after i've spoken to the guy at go-dive...

Just got back from Anglesey - had lots of fun explaining to the other guys at the club that the number of people using twin-sets was going to be doubling soon (there's only one twin-set user at our club) and got a fair bit of stick...

Most of the peeps who can sign the boat out do 2 half hour dives off a 15L with a pony for redundancy - after the usual comments about twin-sets being too heavy, i mentioned the fact i was probably going to get 7's - hence the comment about two half hour dives and the fact they have 18L of air in total - which is fair enough.

So, still going to do the calcs, but it may be a 10L twinset after all. I was told to run before i can walk too - but the way i see it it's time to innovate and not imitate - there's more than one way to redundancy...

A couple of things in favour of twins though - Main cylinders and ponys are bloody awkward - and - it would be hard to forget your twin set... Not that anyone forgot their pony!!

PS - if anyone from my club reads this i'm only messin' wit ya!

[Mdemon]

FWIW, I've modded my Buddy ABS backplate.

There are two indentations in washer-sized holes which are (obviously) the place to drill.  The plastic is surprisingly thick there, about 7 to 10mm.  Now, you could just use SS washers, a bolt and some nuts.  I am hanging 2*12s + 12Kg lead of these bolts, so I filled in the recesses with JB Weld (Epoxy steel) and put the washers on the outside of that.  I did also put a strip of galvanised metal (3mm thick) between the holes as a precaution. but I think that was belt and braces.

Whilst Buddy won't guarantee anything, they were happy to tell me several people have done this successfully and have also used a manifold with the cam bands.  I have spoken to a couple of divers who have also done the mod.

Easy to do.

Anyone know how much 2*full 7's@300bar weighs please?

HTH

[Dominic]

Originally Posted by [b

Quote[/b] ]Anyone know how much 2*full 7's@300bar weighs please?

Assuming Fabers, from 8.2 to 11.6kg per cylinder.
Each will hold 2.5kg air
So a full twinset will weigh at least 21kg...

[Justin Owen]

Mdemon - cheers mate! The mod does look relatively simple - but it's good to know how other people have done it! Only think that concerns me slightly is that one of the recesses on my jacket isnt very deep - wouldn't you end up with the wing-nuts digging in your back...?

[MartinS]

Hi Justin

Just to chuck a few more worms into the can...

I did this mod, but used the custom diver's mushroom headed nuts (these can be bought seperately), so you don't feel them at all. Didn't last long though as I have just changed to a s/s backplate but only because I found the buddy harness a little awkward with the weight of twin 12s and I just didn't think it would last very long (looked a little too stretched in places, and the harness is quite flimsy, especially when wet).
It just gets a bit more complicated with a s/s backplate as you have to either buy a harness (DW do a harness with/without shoulder clip for less than £60, or you can make your own one-piece for about (and this is only a rough estimate) £20-30.
HTH
Martin

[Mr T.]

bump

[wreckweasel]

Debump... its booooring :P

[Justin Owen]

I was very surprised to see this thread again! But it's quite apt as i've been scratching my head the past few minutes trying to figure out where I should post about my twinset/manifold/bands/wing/harness/weighting issues etc etc...!

God I was such a numpty back in 2003, seems very strange reading those old posts...!

Anyway, anyone interested in the latest...?

Thanks to lots of people on here, esp Digger and Dom (for his website), I ended up with twin 7's, combro backplate, digger-harness, tekwing, 2x apeks DST4's and a 1.5m hose...

After an hour in the pool last wednesday, my thoughts so far as follows, which may be useful as I know a few people were looking at a similar setup...

Weighting:

I only need 2kg for the pool, so will be looking at a weight in the channel of the backplate (v-weight?). It was very difficult to keep my feet down, i didn't have ankle weights on as i don't need them normally in fresh water. Might have to look at a tail-weight possibly...?

Hose routing:

I had the 1st-stages horizontal at first, but had a few problems... Using a hog-loop the hose was too tight and pulling my head to side, not very comfortable... Also the 1st stages got very close to isolator. Out of water have now inverted the 1st stages, which has given me a few inches on the problem hoses and tidied things up a bit, will post back on how things go...

Tek-wing:

The huge dumping elbow gets in the way... When the wings even partially inflated its pressed hard against cylinders. I know a few people have replaced their's with a non-dumping elbow. With that in mind i checked the blanking plate (where the other shoulder dump would normally go) and its firmly welding/glued in position... Also, whats with the GIANT corrugated hose...!? Currently working up the courage to take the scissors to it...

Backplate/harness:

No real problems here, but some did mention last week - is the backplate likely to damage a drysuit? Esp the zip...? I have a heavy cordura suit so that should be ok - but has anyone suffered zip damage...!?

Anyway, better do some work...!

[Dominic]

The huge dumping elbow gets in the way...

Yup, PITA isn't it?

When the wings even partially inflated its pressed hard against cylinders. I know a few people have replaced their's with a non-dumping elbow.

I did that. . .

Also, whats with the GIANT corrugated hose...!? Currently working up the courage to take the scissors to it...

Nah, use a sharp knife instead, cuts neater. . .