Aluminum tube jointing methods

[Deskpilot]

Remember some time ago, Yenn started a thread on designing our own cheap recreational aircraft? Well we were heading for another Camel (an animal designed by a committee) before the whole thing came to a ignominious end. I still have the yen (excuse the pun) to design something simple that the average person could build. I'm thinking of aluminum alloy construction but can't find any info on the web with regards to joint design/methods. I'm thinking on the lines of a mid (shoulder)wing with a plain tube 'fuselage' boom joining it at the main (tubular) wing-spar. The 'cockpit' would would also be a basic tubular construction with the option of a pod etc. Ideally I want the empennage to be in line with the boom, not on top or beneath it. I want to stay away from specialized welding, so what method's are available and proven.

 

What I would dearly like, is a set of drawings showing how to join tubes of various sizes and at various angles to each other.

 

I have Bill Whitney's aircraft design videos but they don't cover the actual engineering side of design.

 

Any aeronautical engineers out there who can speak in lay mans terms? I'd like to hear from you

 

 

[sain]

there is a fair bit of info on http://www.homebuiltairplanes.com/forums/

 

looks like your main options are welded (out due to design decision) bolted (ala the skyranger or whatever it is) or riveted....

 

The skyranger sounds vaguely similair to what you want to do, so it might be worthwhile checking out a few of those to see how they've done it.. buildlogs might help here.

 

There is another aircraft which used a couple of fairly chunky ring type fittings to join the tail boom and empenage onto the body and wings.. i just don't remeber what aircraft type it was. basically (from memory) the ring dohickey went around the boom, and was rivetted to it. other aluminium tubes were then joined onto the ring as well, though i don't remeber if they were bolted or riveted. riveted seems most likely. Anyway if your custom designing something like this you may want to make use of people like http://www.emachineshop.com/ to build it for you (you design it using their cad software, send it off, they make it with their cnc machines and send it back.)

 

wish i could remeber the name of that aircraft...

 

 

[Yenn]

Yes I am still here and still toying with designing my own.

 

I have plans for Graham Lees Nieuport which uses aluminium tube. The connections are mainly rivetted using an aluminium gusset wrapped around the joint.

 

Where there is a difference of diameter the gusset wraps around the larger dia. and runs down the length of the smaller tube for a short distance. The first rivet goes in at the far end of the gusset from the bigger tube. Next rivet goes close to the big tube. pulling the gusset in and tightening it.

 

Other joints such as the wing attachments use a filler plug, bolted inside the tube with a threaded centre or similar variations on the same theme.

 

If you PM me with your email I can photocopy and send to you, or I may even be able to send pics to you in a pm.

 

 

[Downunder]

Various pics of joins here.... http://www.airdromeairplanes.com/Default.asp?page=75

 

 

[Deskpilot]

Hey Fonzie Downunder, thanks for the link mate. This could be easier than I thought.