setting up doubles

[Mike D]

I was setting up double 100's and everything was going smoothly.....I noticed however that when I put the bands on the tanks the crossbar did not move smoothly at all. Is this a problem? Stress on the crossbar or is it supposed to be like this?

Thanks for any feedback.

 

[Davidstealey3]

the manifold should not move at all when the tanks are completly finished, but need more info

the manifold has a lock nut on each side to lock it in place, did you tighten them down yet?

i know when i did mine the tanks were not evenly spaced because of the need to get the manifold in a position as to reach it when being worn.

also you might have the wrong bands but i find that unlikely.

i am not the formost person for this question as i have only put together one set of doubles myself, but i did make a jig for putting the manifold in and the tank bands on when putting them together.

hopefuly someone else will reply to this that has done a hundred sets or so over time and will know what you need to do. all i can comment on is what i have ran into on myown

 

[Scared Silly]

With the bands on but with out the lock nuts tightened the cross-over should freely move. It may only move 1/2 a turn or so but it should freely move. Further, it should freely move even under pressure.

With the sets that I have put together the free range of the cross-over is not always where I need the valve to be. For instance, I have the cross-over valve at about 45 degrees pointing forward. Yet the free range might be centered elsewhere. To get it to the correct position I might turn it one way or the other going which ever direction puts the least amount of stress on the threads.

When assembling the manifold you want to make sure both sides grab at the same time. Often this step can be the hardest especially if the surface the cylinders are on is not perfectly flat.

Edit - also asked here:

http://www.scubaboard.com/forums/ad...ns/304968-setting-up-doubles.html#post4725252

 

[SDAnderson]

Be very careful - it's easy to do irreparable damage to your manifold if you screw this up.

Assemble the manifold on the cylinders, then place the bands on the cylinders. Adjust (rotate) the manifold so that it floats freely before you start to tighten the bands.

As you tighten the bands you will change the distance between the cylinders and need to continue to adjust the manifold to ensure that it still rotates freely. It won't usually float a full turn - at least not easily - but float it should. If it doesn't, something is out of alignment.

It's tricky getting the two cylinders, bands and manifold all properly lined up in 3-space. Be sure you're on a truly flat surface, measure frequently and proceed slowly.

The first time up you really should try and do this with somebody who has hands-on experience at it.

 

[Scott]

I agree you should really try this with someone who has experience. If you don't have that luxury Dive Rite has a good tutorial.
Assembling Double Cylinders - Dive Gear Express