Bracing, what & where?

[Caledonian]

At long last I've got back to my spit/rotisserie project and getting a materials list ready.
One thing, among many, I'm not sure about is where to brace the end frame.
It is basically an inverted T shape 1.2 x 1.2 metres made from 50x50x3 box.
Firstly what should I use for the braces? 40x40x3, 50x50x3, 25x25x2?
Secondly where? Full height to full width or can bracing be lower/narrower?
I was thinking 50x50x3 and full height to width (end of leg) but I'm afraid I am going over the top for a brace and the thing is gonna weigh a ton for moving around.
Any help/advice greatly appreciated,

Jack

 

[piman]

Hello Jack,

what are you going to put on it, as 50 x 50 x 3 is very strong and I doubt if it will need a brace? You could put a small gusset of 3mm plate to reinforce the Tee but I don't really think you'll need it?

Alec

 

[Caledonian]

Thanks Alec

It's gonna be an MR2 Mk1 spinning, hopefully
Engine, gearbox, suspension all removed, so not a lot of weight left.

Jack

 

[piman]

Hello Jack,

I was on the wrong track, I was thinking food.

I made mine with 100 x 50 x 2 box, a bit over the top but I had some to spare. 25 x 25 x 2 would be good enough for a brace at say 60% of length, although I don't really like welding dis-similar sized sections together so I'd probably weld some 50 x 6 flat across the 50 x 50 then weld the 25 x 25 to that.

Alec

 

[Caledonian]

Hi Alec

Understandable, it was lunchtime and I wasn't very clear.
I'll work it out on the basis of what you suggest,
Thanks

Jack

 

[rikrobson]

25mm box will be sufficient I would have thought. Most of the stuff you see in the mags is only 20-25mm.

I'd brace 300mm on the Tee with the same box. its not gonna go anywhere.

That or make an 'A' frame instead of an inverted Tee.

I find planning it in google sketchup helps.

What have you planned for the pivots and cradles?

 

[Caledonian]

Hey Rik

I've got it all planned out now on sketchup reality is the next step lol
I'm thinking about a couple of lengths of thick wall tube I've got for the pivot.
Given that it will turn at about 4 or 5 RPY (revolutions per year) I think they'll do the job.
Crossbar will be 40 x 40 x 3 box mounted to bumper mounts

Jack

 

[John_Duffy]

Hello Jack,

I was on the wrong track, I was thinking food.

Alec

Yes, I was also wondering what kind of beast he was bbq-ing!!