we had one at our club that was built on a high tension tower the local power company sold us. they had changed the line over to larger towers.
We didn't have nay plans,just put the tower up and built a shack on top. Built a staircase up the inside and entered through a trap door in the floor. I have to say the target opening (automatic trap) was about 30 feet up or so.
Then we had to put a cyclone fence around it because it was an "attractive nuisance" that kids might fand appealing and injure themselves falling off.
It was a lot of fun but eventually got old and we gave it to a sportie place about 4 miles from here.
Our club was gifted an old construction material hoist that goes up about 30'. We built a house for the trap machine and mounted it to the forks. They run it up to whatever height they want. The thing is basically a forklift with no wheels.
We looked at replacing it (it dates from the 50's and is old, ugly, some safety issues). The basic proposal was for a 30' piece of 8" square structural tubing for a column, a good concrete base, a winch and pully system, and a platform for the machine. It started getting kind of pricy so we just repainted the the material hoist and fixed the safety issues.
Our club has a 75' tower. It is a 36" tube, 75'+ long, set about 8" in concrete, with 3 guy wires running off about 120 degrees apart. There is a 5' square roofed platform on top with a hoist raising a machine on a platform up 2 rightangle guides to the top. At one time it had a spring loaded dog type of arrangement for setting the height and to stop it from falling from the set height, but it just folded up when a loaded machine had a power screwup, and powered down. It needs an elevator type deadman lockup on the guides to stop it falling in the event of a power interuption, and a dog type arrangement to hold it at the required height on crossbars between the vertical guides. It can be lifted off the crossbars, dogs retracted, and lowered to be refilled or put into storage.
We have thrown regular birds, minis and battues from it. Minis and battues can be a challenge, I'll tell you!
Thanks for all the suggestion, the last seems most appropriate. The utility pole is probably the most cost effective. I was hoping for some kind of platform plans and pulley system design that was out there. guess not. seems that everyone is using whatever they have to get a machine up 30+ feet. A 30 foot high pole barn with stairs up to the platform seems to be the most cost effective.
We are probably going to settle on a electrical scissor lift. The platform type with wheels on the bottom. they are everywhere and functional but beat up one can be had for a few grand, and can be easily moved to change up the location of the thrower.
The scissor lift seems to be the common solution for a tower at most clubs these days. Look for a large wide one so it is stable. There a bunches being sold at auction each week, look at Richie Bros Auctions, I believe you can even bid online once you register. Maybe there's a Richie Bros near you?