Well great...

Kim , running bladder pressure is easier than most think. It's not voodoo magic. Simplicity is key aside from a few other important factors. The example that's shown on Texas Timer's website is over the top. All the crazy fittings and gizmos that are shown are just airleaks in the making. An air leak is going to not want to needle properly. All of my 1/2A bladders have nothing more than a knot in the rear and generally I use on fitting which is a long 1/8" pop rivet with it's center knocked out. I then place the rivet with it's rim side into the bladder material and use a small piece of fuel tubing stretched over it for retention ( snap ring pliers work great here). I make up dozens of them. I've gone away from the transparent latex that you show due to many failures usually in the sunlight. That tubing will discolor when it ages and failures are quite common. The next most important thing is prop choices, when running bladder it's easier to needle using a smaller than usual prop and also pitch. This allows easier needle settings and allows the engine to unload.

Experimenting is most important which is more than likely due to engine condition which allows some to have a little more grunt. I've used many pinch off devices, line clips, hemostats, wire loops bent which I slide the tubing into which pinches it off. Last week I made another pair of my pinchers. A very simple tool AND SMALL  I made from maple which uses a sewing bobbin for a pivot.  I prefer these due to their light weight and simplicity. I leave the pincher on the plane until I get the engine running on prime and I quickly pop them off. If they fall in the grass the colors quickly make them apparent.

I've made venturi's from used glow plugs and drilled out the center post. You can drill a 3/32" hole into one of the flats of the plug and solder in a piece of 3/32" tubing. I run a remote needle using these. I use a wheel collar with the Cox 128 TPI threaded spraybar soldered within the wheel collar. The hole in the spraybar lines up with the setscrew hole in the collar. You can solder in tubing into the threaded set screw hole. This makes a banjo fitting with the spraybar incorporated into it. I can provide pictures for you if you would like. THis is a very cool setup. Not only does it work well it looks good. The glow plug venturi's allow you to play around with different sizes and it costs virtually nothing. 5/32" is the largest you can go on the stock TD venturi without breaking out of the sprinkler internally. The glow plug allows for larger. Ken

I don't use end caps on 1/2A's  but .22 rim shells will equally work well for bladder end caps, the HELP! section in the auto store can yield some even simpler and interesting fittings for bladder useage. I always wire tie my bladders onto their respective fittings.  The green floral arrangement wire works very well here due to being able to wind it tight without breaking. BE SURE NOT LEAVE A TAG OF WIRE PROTRUDING, this will puncture your bladder. I've pictured from the top to bottom my examples of bladders. On the top is the 1/2A which is a surgical membrane tubing, second is my speed limit bladders which is medium wall and on the bottom is fast bladders for .36 size engines which utilizes an extremely thick wall bladder, the tubing is almost 1/8" wall thickness. Ken