Doubles Question

[Otter]

I have assemlbed my first set of doubles. The crossover still moves, but clearly its has become more difficult to move as I tightened the tanks bands.

How difficult should it be to move the crossover piece?

Thanks.

 

[WarmWaterDiver]

Laterally or axially?

 

[Leadking]

I have assemlbed my first set of doubles. The crossover still moves, but clearly its has become more difficult to move as I tightened the tanks bands.

How difficult should it be to move the crossover piece?

Thanks.

Have you tightened the jam nuts? (the thin nuts on each side or the crossover)

 

[Whitelightnin]

The crossover should be able to turn. It doesn't have to be "free spinning" loose but it shouldn't be "real hard " to turn either. You might need to adjust it a little as you tighten up the bands to keep it free. Also, watch that the bands aren't trying to "roll" the tanks towards each other & bind them up that way.

After you get them set up, you can tighten up the nuts on the crossover if you want to. I leave mine loose. It's fine either way.

James

 

[simbrooks]

Laterally or axially?

Or radially - which as many others have said you should be able to slowly spin it around for optimal positioning, but it should be firm enough to stay there. I hope not axially or laterally, then i would worry about stress on the manifold due to your bands being too loose. Assemble the tanks on a table, dropping the ends off side alternately to get the bands on easier and keep everything flat and inline.

 

[Otter]

I think radially. I can move it one handed, but it definitely more difficult than before I tightened them down.

The tanks lie flat...as for rolling, I am not sure HOW to check that. Eyeballing them, they look fine...

 

[matt_unique]

I think radially. I can move it one handed, but it definitely more difficult than before I tightened them down.

The tanks lie flat...as for rolling, I am not sure HOW to check that. Eyeballing them, they look fine...

Tough to tell from the written description. You should be able to move the isolator as you described. It's OK if it's snug but that is such a relative term. It sounds OK if you can move it with one hand. A key step once you have the complete manifold/valves into the tanks is to lay the tanks down on a flat floor with bands loose. Press down on the top of tank 1 while pressing on the bottom of tank 2. Then press the top of tank 2 while pressing the bottom of tank 1. Know what I mean? This helps ensure the tanks are in alignment. Once this is done, carefully tighten the bands without moving the tanks at all. If you have access to a tech shop they would help ensure you are setup properly.

--Matt

 

[Otter]

Tough to tell from the written description. You should be able to move the isolator as you described. It's OK if it's snug but that is such a relative term. It sounds OK if you can move it with one hand. A key step once you have the complete manifold/valves into the tanks is to lay the tanks down on a flat floor with bands loose. Press down on the top of tank 1 while pressing on the bottom of tank 2. Then press the top of tank 2 while pressing the bottom of tank 1. Know what I mean? This helps ensure the tanks are in alignment. Once this is done, carefully tighten the bands without moving the tanks at all. If you have access to a tech shop they would help ensure you are setup properly.

--Matt

Matt, they lay flat on the concrete now so I don't think I am getting any wobble/tweaking on them. I am less confident about them rolling and therefore binding just a bit...I wish there was a reasonable tech shop around here. SoCal doesn't have many tech divers, so its largely learn on your own...unless I head down to San Diego...or up to Malibu....

 

[matt_unique]

Matt, they lay flat on the concrete now so I don't think I am getting any wobble/tweaking on them. I am less confident about them rolling and therefore binding just a bit...I wish there was a reasonable tech shop around here. SoCal doesn't have many tech divers, so its largely learn on your own...unless I head down to San Diego...or up to Malibu....

If you do the steps I mentioned above with your doubles already banded you would see right away if they were not aligned. If there was almost any movement at all they would not be aligned. (You would see them moving and possibly bumping the floor a bit). If this is not the case, then it sounds like they are aligned from that perspective.

You mention you were less confident about them rolling and binding. As I reread I don't follow what you mean.

--Matt

 

[Otter]

...
You mention you were less confident about them rolling and binding. As I reread I don't follow what you mean.

--Matt

So that the valves are not facing each other anymore. The only thing keeping the valves in alignment is he crossover, so I was wondering if the binding might be because of the tanks 'turning' inside the bands as the bands are tightening down that last little bit.

How important is it to 'stretch' the bands before installing them? Thats a step I skipped.