"Jet" Power Compressed Air Bladder

[mbauer]

How to Make A Compressed Air Bladder for a Papermodel Power Source!

This bladder works great for PaperModels because the paper doesn’t act like shrapnel if the bladder explodes!

Parental Guidance is needed for people younger than 14!

CAUTION:

Like all hobbies you must use care when dealing with any power source!

The bladder uses compressed air. This compressed air is a very high energy. It can explode and hurt you! Please use the following pre-cautions when filling or near a filled bladder:

1) Always wear heavy leather gloves when filling. Safety goggles to protect your eyes would be a wise choice too.

2) Design your models with a safety zone between the bladder and the paper wall of your model. At least a 1/2” air space will help protect your hand. This stops direct contact with the bladder!

3) Never use a “valve as a nozzle. A filled bladder sitting around can explode if Static Electricity comes in contact! See photo below of what is left of a F104 model that I used a valve on.

4) Anything that will cause a regular balloon to explode will do the same with these bladders. They are really high-powered balloons!

I have had 3-bladders explode on me. Two were made using super-glue. Using rubber bands to make them has really helped with the safety. The third was when the model was filled and sitting on a shag carpet floor. I walked across the floor in stocking feet, when reaching down to pick the model up, the contact made the bladder explode from Static Electricity that was built up!

Using a 1/4”I.D. x 3/16” wall latex tube can give 11-oz of thrust with a fiberglass tube! They grow about 3”-long for every inch of length unfilled!”

I’ve included a photo of an Elevator system that I made to counter-act the CG shift when the bladder is full. It worked but is very hard to adjust it. When the bladder is full it is designed to move the Elevator up causing the nose to climb or at least stay level. Once it empties the Elevator returns to the glide position thru the use of a rubber band attached to the rudder.
This photo is included to help give ideas on the use of the energy from the bladder expansion/contraction. Instead of a rubber band a small torsion spring (the kind in music box lids) can be used. They can be bought from McMaster-Car web site that is listed in the construction PDF.

Have fun and please be carefullif you make some!

Mike

[SCEtoAUX]

Oh the possibilities! Mwahahahaha :D

Looks good. Thanks.

[Don Boose]

The destruction of that airplane is even greater than that which I have achieved from time to time by turning the rubber band one too many turns.

Don

[mbauer]

Yes, destroyed, but some parts were re-usable; used the tail feathers and wings on a new model saving construction time.

Mike