Put the thermostat inside something with insulation to damp the temperature change locally? IE, put it in one of those 55 gallon drums you mentioned, or something much smaller if possible.
probably a variation of the double wedge, but run a threaded rod down the center and have the cylinder cut into 3 pieces with opposite angles at the interfaces so that when you tighten the threaded rod down there is compression.
If you are tapping into aluminum, you can put the screw in one time to a sufficient torque to prevent the bolt from vibrating loose. But If you remove that bolt then try to tighten it again you will find that the threads will most likely be damaged beyond use.
If you want to do it well, then...
My corvair has an Aluminum to Steel interface in the combustion chamber. Gm saw fit to put .032in. Copper Gaskets between these 2 surfaces way back in 1960. If you could get good reliable metal on metal sealing that doesn't destroy itself with heat cycling, then we would have dispensed with...
Tire companies who make Pneumatic pressure vessels that rotate at high speeds always burst test tires with Water.
As for the energy stored in Steam vs Air. That is a no brainer.
We have had tires explode and send pieces through concrete barriers. What happens if one of your rolls explodes...
Make the wheels out of very hard plastic so when you take a corner too fast the wheels slip to relieve some of the cornering force that might make it slip.
Can you design it in a way that there are counter-balancers in the root of the hub that can be pushed out in the case of high inertia to shorten the turbines?
Or just have some fluid that will fill the internal passages of the blades if they get out of control?
Or, how about it pivots itself...
From my experience, Shock loads are death to Ball screws. I couldn't speak on roller screws. There are other options out there for linear motion. Roller Pinion, Linear Motor, just to name a couple options.
I worked at a bike shop for 8 years while I was getting my degree. If you want some information about bicycle testing, I would call up Cannondale, which is a bike manufacturer in PA. They have moved all of their production overseas but still do testing in the states. They had open tours of...
Do you require constant velocity?
I have had good luck with Flexible drive shafts similar to this.
http://www.mcmaster.com/#flexible-drive-shafts/=evkgsx
If you want to actually drive it with a motor per your statement. Then you need an actuator. I would search screw jack for pretty inexpensive version that a motor will attach to.
We do alot of weld-ments and we usually just put extra material anywhere we need to locate something precisely and have post welding machine processes to get it there. But if you put a tolerance on a drawing it is up to the fabricator to meet that tolerance for the cost that they quoted you.
I...
