Two issues with substituting 304 stainless for 4130:Hi everyone out there! I have a question is 1.4301 austenitic stainless steel usable for the hundreds of brackets and connections in a wooden aircraft construction - in this case a cub? The reason I ask is that I can find specs for the chrome-moly tubing everywhere, but not a mention of the ‘requirements’ for these parts. My job involves this material almost exclusively and since I’m running the 4kw laser-cutter at the moment and can use a 70-ton brake for the bending; I’m otherwise actually employed as a TIG-welder, so it would be very ‘convenient’ for me if this material is allowed in aircraft construction… just a thought!
Look forward to your expert opinions! Peter
I think he's referring to the usual amount of metal stuff in a wooden airplane. Wing, strut, and tail attach parts, control surface hinges and bellcranks, control stick and rudder bars, and so on. There's an amazing amount of welded steel stuff in a wooden airplane.What brackets then ?
Different cultures but you might ask...it is not like the two look alikeMy boss would kill me if I brought 4130 in to cut or work on!...
No....you only need that when you start to assemble, all your ribs and fittings probably could fit under your bed. You could spend a long time building before you needed to rent the larger space which would save enough money to buy the the 4130 and or the spruce.First off, I have to find a space upwards of approximately 8m x 4m for the build! Without that, this is all just so much pie in the sky! thanks for all the input so far, all very interesting…
I knew a guy that took the plans for a J3 Cub copy and substituted titanium tubing for 4130 tubing but I have no idea about the diameters or wall thickness changes or what exact titaniumAs a general rule of thumb: more austenitic the structure, the more it is prone to work hardening and intergranular / stress corrosion cracking (thus the fatigue issues). I know just enough phys-met & NACE stuff to know when I need to seek professional advice before challenging the status quo. The thought of watching my wing fluttering down while looking up through a spinning canopy powers these thoughts. And YES: these are subjects directly related to aluminum alloys as well (ref: deHaviland Comet).
I will try to be careful writing this:...there was once a motorcycle race shop that sold snowmotwitty machines to keep the doors open in the winter. A certain DC3 captain had a kid who was a pretty decent snow rider, so some "friends and relatives" who worked in a nearby...uh...BUSINESS that did a LOT in unobtanium fabricating took apart a relatively common small displacement snowmo chassis and duplicated most of the parts in said exotic alloy. These parts and sub assemblies, well, uh...SOMEHOW made it to the DakJock's home and turned into what looked like a fairly pedestrian production machine - with a VERY high performance motor. His kid won a lot of cross country races (under sponsorship of afforementioned shop) but let's just say very few people ever knew just why that darned thing was so bloody fast and strong.I knew a guy that took the plans for a J3 Cub copy and substituted titanium tubing for 4130 tubing but I have no idea about the diameters or wall thickness changes or what exact titanium
alloy was selected. He did say the result was lighter and stronger. He was a welder for an aerospace company that fabricated a lot using titanium and he knew how to do it.