DIY, low profile STA

[JimC]

I finaly god fed up with the usless integrated STA in my Halcyon wing, so I decided to think up something to replace it. I didn't want a cludge from the hardware store, I wanted a real STA. So I opened up my CAD program (MS Paint!) and started jotting down a layout.

10 minutes later I had a good idea of what would be involved. So I took advantage of my mothers work having a full machine shop. Lucky me!

Laser cut, machine bent.. here are the results. It clears the t-nut by less than an 1/8th of an inch, fits on well with my homeade channel weight.. and its rock solid.

[el-ninio]

can you post the exact desighen for this? what size tanks work with your desighn? dont you have a problem with the STA turning around?

I'm very interested, as I need a very light wight STA, as I'm rather dense (litraly), and only need about 2# with an AL80 tank (12L for metric people) and a dive skin.

[JimC]

The picture is an AL 80. I designed it to fit an the diamiter of an 80 as close as I could. The main goal was for larger E8's, which will clear the t-nut a wee bit more. An old 72 might fit, but it would be damn close.

The STA's are on very tight and don't spin. To tighten them I finger tightened, then spun the STA into place. Took a few times to get them to tighten down in the right spot. If they slip I'll shoot some locktight in.

Pictured above is an AL80.

Things I like about it more than versions you could buy online:

- It works with my channel weight.
- Its super low profile. The tank sits closer than it did with the integrated cludge from Halcyon (now removed).
- Its wider than any I have seen, for incredible stability.
- I made it my self. :)

My design was unfortunatly lost via a HD crash, but I'll mesure STA and stick some drawings up later.

[Soggy]

JimC once bubbled...
I finaly god fed up with the usless integrated STA in my Halcyon wing, so I decided to think up something to replace it.

How is it useless? I dive with both a weighted STA and the integrated STA depending on if I am wet or dry and I don't notice any difference between the two except my tank is further away from my head with the STA.

[JimC]

The bolt heads get in the way and prevent even a reasonable seating.

The thing is to narrow to provide a solid rest, even without the bolts in.

If your not carfull you can put the backplate on crooked. With the tank resting between a bolt head and one of the rods.


All in all, it just dousn't do the job very well.

[Soggy]

JimC once bubbled...
The bolt heads get in the way and prevent even a reasonable seating.

Perhaps you have the wrong hardware or something. My bolts are actually recessed and definitely don't get in the way. I have put the backplate on slightly crooked before, though.

[nickjb]

I've dived my single wing and backplate for about a year withouth any kind of STA. Once the cam bands are tight everything stays in place. It is possible to fit the tank crooked but it is easy to avoid. I've been meaning to a cable tie to make it impossible but it isn't a big enough issue.

Nick

[JimC]

I dove the integrated STA for a year too.

I might have gotten the wrong hardware, who knows. All I know is this STA is more solid and easier to use. :)

[Soggy]

JimC once bubbled...
I might have gotten the wrong hardware, who knows. All I know is this STA is more solid and easier to use. :)

And...ultimately...that's what counts!

I also like my STA because I can easily take my wing off to rinse it rather than having to deal with the 6 lb backplate also.

[Mo2vation]

nickjb once bubbled...
It is possible to fit the tank crooked but it is easy to avoid. I've been meaning to a cable tie to make it impossible but it isn't a big enough issue.

Nick


I don't have the DIY gene... houw whould you fashion a cable tie / zip tie / tie wrap thingie to "make it impossible..."

I have the integrated STA - couldn't be more pleased. Never a slippage issue, but sometimes I need to reset to get it straight, If I'm snoozin' at set up.

Enlighten me.

Thanks -

K

[nickjb]

Mo2vation once bubbled...



I don't have the DIY gene... houw whould you fashion a cable tie / zip tie / tie wrap thingie to "make it impossible..."

I have the integrated STA - couldn't be more pleased. Never a slippage issue, but sometimes I need to reset to get it straight, If I'm snoozin' at set up.

Enlighten me.

Thanks -

K

I've not had a close look at the Halcyon wing so I'm not sure how they are set up. I was going to put a couple of holes in the cam bands (with a soldering iron) and some corresponding holes in my backplate and wing. Once a zip tie is looped through the lot everything should stay aligned while the bands are tightened.

HTH
Nick

[JimC]

Here are the mesurements.

[el-ninio]

I've noticed that some BP have more then one set of holes for bolts. are they close enouth to pass two if then through the 2.5" sta? could give you some aditional stability.

[ShoalDiverSA]

el-ninio once bubbled...
... are they close enouth to pass two if then through the 2.5" sta? ...

From what I can gather/surmise, the distance between the holes is about 1.5", so you should be able to fit two bolts in on your STA. AFAIK, the two holes allow you to adjust your trim by mounting your tank higher or lower on the backplate, so you would lose this "feature". Judging from backplate phot's I have seen, some manufacturers have added another hole between the two holes most other bp's have. So with that bp, you could drill two holes .75" apart on your STA and still have two mounting positions with two bolts holding the STA in place. Having said that, there is probably no good reason why you couldn't drill the holes yourself if your backplate doesn't have them. If you wanted more range to set your trim, there might be enough space below the bottom hole (where you head is at the top) to drill another hole spaced .75" from it. Do the same on the top set of holes and you should now have four holes per group and three adjustment positions.

I have just realised that I have warbled a lot now and it still doesn't make sense to me. For the sake of clarity, I have scribbled on the Roger Lacasse design to indicate what I am getting at. Your STA would have to be drilled with holes .75" apart for this to work.

I don't know how much of an advantage additional bolts would be. If you are really concerned about the bolts coming undone - use SS Nylock nuts. I must be honest, I can't imagine the bolts coming out if they were properly secured.

One of the STA designs gets around the problem of the STA rotating by making the first bend on the STA down towards the backplate, i.e. the STA wraps around the "spine" of the BP and then bends up and away towards the cylinder. This could also be achieved on a custom unit, with a bit of effort.

WARNING: All measurements expressed in inches were first converted from millimetres to cubic furlongs per BTU-foot and then to the final measurements via a complex algorithm :confused: - measure (your b/p) twice, cut once!

And all this from someone who doesn't even own a bp/wing setup yet (but I am working on it). :D

I await corrections... :notworthy:

Cheers,

Andrew

[ElectricZombie]

Nice STA, well done.

I have not had any problems with the integrated STA in my Pioneer wing. Seems to work great.

[ShoalDiverSA]

Kinda related, so I did not feel it justified a new thread.

:off:

Can anyone help with the dimensions for a tri-glide? I would like to make some (can you say drill and file!?), but no examples...

I have attached a drawing of one with my own ideas of the dimensions. Any confirmations/better ideas? This is for 2" webbing. I have marked the dimensions with letters for easy reference.

Thanks for the help!

Cheers,

Andrew

[polkster13]

I bought my Halcyon wing the year that they came out with the integrated design so you did not have to use the seperate STA - single tank adaptor. The bolts I received with my wing had round heads on them that would cause the tank to sit crooked (the tank was runbbing against the head of the screws) and these would also mar my tank. After trying several different things, none to my satisfaction, I contacted Halcyon and they informed me I had been sent the wrong screws! They then immediately sent me three replacement screws (one spare) at no cost. These have a flat head and when tightened down they do not stick up and mar my tank. I still have to be careful when putting on the straps or I will end up with the tank crooked but it is my fault and not the fault of the screw heads sticking up too far.

If anyone else is having this problem, I would encourage them to contact Halcyon immediately to get replacement hardware.

[ElectricZombie]

ShoalDiverSA once bubbled...
I would like to make some (can you say drill and file


It would be a lot easier just to buy some. They are only $2.00 - $3.00 each. It would take you forever to make one with only a drill and a file.

[ShoalDiverSA]

I agree, drill and file sounds too much like hard work. I submitted the drawing with my guess-timate dimensions to a laser cutting place and can get them cut from 3mm 316L SS for about R8 (about $1.15 at today's exchange rate). This also saves me shipping as all our Scuba accessories are imported. By the way, the price to cut a D-ring is about the same.

I am still going to get the price for them from my LDS for interest's sake.

Cheers,

Andrew