Author Topic: Rivets, Tin Snips, and Files (Read 4142 times)

Vince Carucci · « **on:** April 16, 2019, 07:35:30 PM »

Elevators, rudder, and vert stab finished. Just need to assemble the horizontal stabs and the tail is formed. Only thing left after that is hinges and covering.

I coped all ribs and tubes where they met 3/4" tubing for a snug fit. 2024-T3 sheets were used for nearly all gussets. Where ever two different tube sizes came together, I needed to shape gussets too complex for the stiff -T3 aluminum. So I purchased a sheet of 2024-T0 and formed the gussets from that. It was as easy to form as putty. Once formed, they were heat treated to -T3. It made for a very clean, very strong fit.

jrbirdman47 · « **Reply #1 on:** April 16, 2019, 11:58:30 PM »

Very nice, clean looking build!

Jack Lilley · « **Reply #2 on:** April 17, 2019, 03:57:39 PM »

What is the process for heat treating the aluminum?

Vince Carucci · « **Reply #3 on:** April 17, 2019, 05:27:28 PM »

I didn't do it myself. I had access to a shop capable of this process. Otherwise I would have had to find a shop who does this for a fee.

What I do know, is that the parts have to be heated to almost 1000 degrees F' They have to "cook" for a specific period of time. Then they have to be quenched and cooled a certain way to achieve the correct level of hardness. Mine were heated in an oven about 1 cubic foot in size. Not a difficult task for someone with the right equipment following the correct procedures. I don't know how much it would cost commercially to have it done, but it might be worth it for the precise fit that can be achieved. A strong connection on the rudder and elevators is absolutely necessary considering the cyclical stresses they experience.

[IMHO]

Wayne · « **Reply #4 on:** April 20, 2019, 07:21:12 PM »

That is very nice work Vince.

Wayne · « **Reply #5 on:** April 20, 2019, 07:28:18 PM »

Could you heat the T3 while forming it or would that mess with the temper?

Vince Carucci · « **Reply #6 on:** April 21, 2019, 03:43:46 AM »

I don't know the answer to that. But I wouldn't do it for a few reasons: First, I don't know how it will affect the temper. Second, I did all forming with my fingers [ouch]. The ribs should be the same size as the tube where they meet so all that was needed was a clean bend. It was fairly easy to shape the T3 around the tubes to fit the ribs.

1. I bent the gusset around a section of tube. It creates an oversize radius.

2. I then put the gusset around a smaller diameter tube firmly against a block, and applied pressure high and downward with my thumbs. Flip the gusset around to work both sides equally. Check your results around a .75" tube.

3. If you end up with a crown on the gusset, place it over a spare length of tube/dowel and gently tap the crown down with a plastic or wood mallet. Finish shaping against the block until you get the desired shape.

The T0 aluminum was very easy to shape, but there is the added burden of finding a heat treating service.

I hope you find this helpful.