Build an Oleo Strut: Tips, Instructions & Max Energy Absorption

[ElementsnStuff]

I was wondering if anyone could assist me in building my own oleo strut or lead me to some detailed instructions, as I'm new to the metalworking concepts that I presume will be involved.

Also, out of curiosity, how 'absorbant' can an oleo strut be built - that is, what is the maximum energy one can absorb theoretically? I've only ever seen results in the single-digit joules for hobbyists - not too thrilling, to be honest.

 

[Danger]

what is the maximum energy one can absorb theoretically

That is essentially limitless, since no size restrictions are given. That absorption will be through whatever you use as an accumulator or blowoff valve, not the cylinder itself (unless its structural integrity is less than the other 2). If you have only the cylinder with no valving, then back to answer #1.

 

[DaveC426913]

You are building something out of ... margarine??

 

[ElementsnStuff]

That is essentially limitless, since no size restrictions are given. That absorption will be through whatever you use as an accumulator or blowoff valve, not the cylinder itself (unless its structural integrity is less than the other 2). If you have only the cylinder with no valving, then back to answer #1.

Alright then, I guess I can dig up some size restrictions, although these aren't really set in stone. Max dimensions would be 2.5 inches tall by 1.56 inches wide by 1 inch deep.

What is an 'accumulator'?

Also, I thought oleo struts stayed at a constant inner pressure with no load applied - why would a blowoff valve be necessary?

 

[Danger]

Max dimensions would be 2.5 inches tall by 1.56 inches wide by 1 inch deep.

In that case, the limits would be upon the structural integrity of the seals and the cylinder components. If those walls are 1/2" thick, it will take more than if they're only .1".

What is an 'accumulator'?

An accumulator is a "reservoir" into which excess fluid is routed and/or stored under pressure.

Also, I thought oleo struts stayed at a constant inner pressure with no load applied - why would a blowoff valve be necessary?

An oleo strut is not just oleo (meaning "oil"); it's actually an air-over-oil hybrid. That should be obvious from the usage, since oil is a liquid and thus not compressible. The pressure is constant while under static conditions, as you say, but those don't exist during use. Blowoff valves are like fuses in an electrical circuit; they let the fluid/air out before it can rupture the working parts.