I'd to make a large-ish (75 x 40cm) aluminium "rack" type thing. Anyone know where I could order some lengths of cut aluminium with bolt holes drilled or - even better - get them welded together for me?

Any fabricators or machine shop should be able to cut and weld aluminium. Might be a lot cheaper to drill the holes yourself and just present it for welding than to get them to make it all.

I'd offer to make it for you (for material cost) but my aluminium welding sucks ass - I always get a colleague at work to do it for me, which has the additional problem of me not getting any practice either, so I never get any better. I really need to spend a few evenings learning. I digress...

Oh, I see. Bolts OR welding. I use a company called Aalco, which has branches nationwide (and will deliver I think) for aluminium. They'll cut to length as well for a tiny fee. Add some drills (you must have a cordless drill, right?) and you'll be away in no time.

Nah I don't have a drill. I used one once, wasn't pretty, swore I wouldn't do it again. I know people who can work drills but drilling aluminium sounds hard, isn't it? Like you'd need a special aluminium-drilling drill end?

So you can make it for me. I'll send you over a badly-drawn diagram with all the dimensions wrong and then I'll yell at you when it doesn't fit together.

Edit: How thick would it need to be to support, say, my weight? I'm about 10 stone. You're an engineer, you should know this off the top of your head.

Nope, you'll drill ally fine with a 'normal' drill. Just use a slightly higher speed if you can because it's a softer material.

Support your weight? In what way? If you are standing on top of it, like a column then not much - maybe half an inch (12mm). If you are standing in the middle of two uprights (on a bar/shelf between them) then you'll need a bit more material. Just depends on the design really.

Are you planning on standing on this 'rack'? Or are you too short and in need of a jooly good stretching?

Edit: Send me a drawing, with the wrong dimensions, and I'll make it badly so it doesn't match your dimensions, and ignore all further correspondence.. Even from lawyers But if you send me a rubbish drawing with vaguely correct dimensions I'll turn it into a proper engineering drawing for you on CAD (and put it in a pdf). On Monday.

Edit2: TGL has a point. 10 stone? I was that when I was about 14, and I'm hardly a heffer these days either.

10 stone? You woman.

Well I might be about 11 stone now. I am a bit scrawny.

The "standing on" thing... I don't know why I asked that. It doesn't need to support my weight at all.

OK here's the thing: I've got a huge plywood pedal board like this one and it's heavy, it must be 10kgs, without the pedals / power supplies, etc. And I'm sick of lugging it around (the being a bit scrawny part applies here).

Anyway, I went to a guitar shop today and they've got these ones that are made out of aluminium, and they weigh next to nothing, but they don't make one the size I want. So I thought I'd make one myself*. The ones I was looking at didn't use very thick metal - only 5mm or so - but I think it was aluminium.

* Get someone who knows what they're doing to make one for myself.

So it would basically be a few 75cm lengths of aluminium maybe 8cm wide with 3cm-or-so gaps between them, making a 75cm x 41cm slotted surface, held together at the ends to two perpendicular lengths with bolts or welds or whatever (screws might be good actually - protrusions on the upper surface would be a bit difficult), and ideally supported off the ground by a few cm to allow me to run cables underneath it.

So I would be pushing on it with one foot sometimes, but not standing on it.

Do you think oxidisation would make it a proper mess and annoying? Or would it need spraying or something?

Right, so from the front it would look a bit like this

|----------------|

And from the top like this

000000000000000
0 0
00000000000000041
0 0
000000000000000
0 0
000000000000000
75

Capable of taking about 20kg (or thereabouts), and quite lightweight?

I'd have thought that was quite easy really.

You won't notice the aluminium oxidising for years really (actually, not entirely true - it oxidises in seconds, which is what protects it, and makes it harder to weld), but a coat of paint, or clear laquer, both available from places like B&Q or Halfords would make it look a bit nicer for longer.

Well, it would be more like

|___________________| <-- but the other way up.

And you got the other dimensions the wrong way around, more like this, but without the protrusions at the ends:

|-----------------------| 75cm
|==================|
|==================|
|==================|
|-----------------------|
40cm (realised 41cm wouldn't fit my case! Told you I'm bad with dimensions)

But yeah apart from that you're pretty much spot on. Only needs to be a couple of cm high and I doubt it even needs to take 20kg.

Do you think it would be easier / cheaper to just have the ends of each slat turned 90 degrees and bolt the sides (legs) on, rather than weld them?

Also, any idea how much this would cost? It sounds like you've bought aluminium services before (for your racey car?)

I weigh less then 8 stone.

Quote from wheel4hummer :

I weigh less then 8 stone.

I've heard that brains weigh a lot.