Hey all! Long time lurker, first time poster. Having been inspired to make my own scratch build, I've hit a little stumbling block. I'm using 10mmx10mm square alu tubing for the frame. (I want it small and light.) While beginning construction on the frame, I made a few L shaped brackets to join corners, then I realised I need to add another axis so to speak. I'll let the pic do the talking: http://i710.photobucket.com/albums/ww107/theelous3/3wayjoint.jpg What's the best way to make a 3 way joint? (Nothing illegal please ) Thanks, Mark. My apologies if this has been covered before, I've searched like crazy and came up with nothing.
To be honest, with how small it is, I'd go get it welded and pay the guy. That would be the strongest way to do it. Other way would be to make tabs on the box section, say cut 1cm off each side but leave one full length (so you got a flap. might need 2 or so on each bit) then fold them inside each other part and attach with pop rivets. Not sure how accurate you would get it mind, I'd still try phoning a few local welders and asking if they can do alu then dropping it off with them.
I would siggest something like this. The shop is for terrarium stuff. Would think you could get that stuff in your area too.
3 way joint Personally, I like to be able to dismantle things I've built so that they can be cleaned down. I've found Superglue does hold quite well with Ali but it's only so good. Araldite i've found to be better for strength. I'd cap two of the rods (probably the one pointing up 12 O'clock, and the one pointing right to 4 O'Clock. I'd then mount in a butt joint on the top and side, and drill through, and then tap a thread so that I could then screw through to secure. The hole would have to be off centre of course otherwise the screws would intefere. The alternative is to add triangular plates on the outside. Depending on what you're doing with this, this could just be araldited if you didn;t want to screw through or weld.
He's speaking of tubes, not solid bars. So yeah, the corner-joints antiHero linked there are actually the best solution.
hxhdhx Thanks for the help guys. I've decided on a solution. Using sheet metal ive cut out L shapes 0.9mm's wide, one side is 3cm and the other 2cm. These secure the outside. On the inside the two horizontal peices are held by a 0.9mm x 4cm strip bent to 90°s. I'll post pics when I get home. Freezing my ass off in town at the moment
This Cleanest way to do it, it's tough, and simple to boot! I was thinking that you could weld up something like that so it fits snugly into each aluminum bar, and secure by running some superglue along the fingers/prongs, slide the aluminum bar on, and clean up residue. The three pronged joint provides the strength, the superglue merely prevents the bars from sliding/vibrating off, and if you ever want to disassemble, a little splash of acetone will dissolve the superglue.
