Legal Eagle XL Has Anyone Bulit The Fuselage With Aluminum Tube?

[rbrochey]

Just curious... I'm also building an Airdrome E III with aluminum tube... before I order all the 4130 I thought I'd ask... Thanks

[Vince Carucci]

4130 is a steel alloy with an exceptional strength to weight ratio. 
It is easy to weld with gas or electricity. 
It is reasonably priced.

I here Aluminum is a bit more complex when it comes to welding. 
It suffers cyclical stress faster than steel. 
It cost more. 

None of these are absolute deal breakers when it comes to using aluminum. But the current design can be built by nearly anyone out of a basement or garage with simple hand tools and equipment. And I can't help but wonder if weight and balance changes by using material with different properties. 

If I am wrong about any of this, others on the forum can clarify.

Vince

[scottiniowa]

Vince is not wrong-  and as he almost pointed out… you certainly can’t replace a 3/4” 4130N tube, with a 3/4” Alum tube without engineering of each cluster and strength properties.

That would be like saying that 6061-T6 alum   is the same as 6063-T5 or is the same as 2024-T3  all different…in so many ways…

[rbrochey]

Yeah I know it's apples and oranges but I was just wondering, and I have seen a chart that shows basically how to convert the properties each way but in the end it's probably just easier to stick to the original plans... usually the case