cutting square holes in 2mm aluminium

ShipsWoofy

ShipsWoofy

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I am trying to build a new power panel and have a lovely sheet of ally perfect for the job.

I would prefer rocker switches to toggle which makes the job far harder.

Given a fairly comprehensive tool kit incl. > 750W drill, dremel, jigsaw, grinder etc. Is there a special tool I can buy to assist or use with what I have. I have a pad saw (after advice on here) which will take hacksaw blades, but imagine that would be a dreadful method of bent blades.

The holes will be approx 30mm by 10mm with little room for error.

If you were considering tackling this what would you do, there are going to be up to 18 so I am looking for a speedy but accurate method.

Or would I be better marking them up and getting them cut in a workshop. All other holes are round so easy enough to manage.

Though I have seen some round toggles but they require a 22mm hole, how do you cut a 22mm with a 1/2" chuck hand drill, I could do 10mm and a cone grinder but it would be a horrible job.

Thoughts anyone?
 
Cheers, the problem with this kind of answer and this is not disrespectful, there are hardly any left who will do stuff for the man in the street. When I was a kid I could wander around the local estate and get all sorts of small jobs done, now it is all the equivalent of B&Q engineering around here.
 
Radio Spares use to do a range of rectangular punch and dies that screwed together through a pilot hole drilled in the sheet, I imagine that they still sell them, try their website.
 
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Radio Spares use to do a range of rectangular punch and dies that screwed together through a pilot hole drilled in the sheet, I imagine that they still sell them, try their website.

[/ QUOTE ]

Can you explain a little more, how do they work?
 
You can get hand operated sheet metal punches from RS Components. They aren't cheap but they are totally accurate. If you can wait it's ebay.
 
I have never come across these before.

As a one off I will try hire first as I am not sure I would ever use them again, unless I start building bespoke panels for people.

Has anyone used them are they difficult to use? Luckily I have a fair bit of waste to cut off this panel so will have some practice pieces.

Just measured the sheet and it is actually between 1.1 and 1.2 mm so even better, is it hard to stop the metal warping doing it by hand?

I love the PBO forum.
 
You drill a pilot hole through the sheet where you want the hole, then you assemble the punch on one side of the sheet and the die on the other and thread a bolt through the punch-sheet-die and tighten up, forcing the punch through the sheet into the die. Hey Presto a square hole (but no round peg!!)
 
I have used the one I have regulary, piece of p**s to use, the design of the punch and die distorts the slug (the bit you punch out) and not the surrounding metal.
 
The place to get the job done is an electronics or electrical company specialising in control or instrumentation panels. You would be looking at a trawl through yellow pages. To use the punches a pilot hole is drilled in the centre and the die mounted one side and the punch on the other. The 2 halves are tightened together with a bolt.
 
Punches for rectangular holes are expensive and I am not even sure if your size is available. Round hole punches are much cheaper and I am pretty sure 22mm is available, though the only one in my workkshop is 19mm (I think, as I have not seen it lately because the workshop gremlin hides things)
If you have access to a metal working lathe making one is a fairly easy turning excercise, and the only slightly difficult bit is case hardening the parts. For a few holes even that is not essential.
The other method is to use a step drill in a drilling machine.
 
Thank you all, that has be a near record solution to a posed problem on here.

Now to decide if I want to own one or not, last time I hired it was a big bugger riveter, later I bought one for less than the hire costs, but that was as I needed it over a full weekend at the boat. At least with one of these if I have everything ready I only need it for maybe 1/2 day.
 
Hi,

Three ways available for a man with your kind of tool kit:

1. By a cheap profile cutter (nibbler) such as a Monodex cutter, (it's a hand tool which cuts out a little strip down the cut without distortion of the sheet, drill a hole first) or if you know someone who does construction site ductwork he'll have one. You can also hire these in electric version.

2. Using a sharp metal cutting chisel, or even an old wood one as its aluminium, and place the metal sheet in a vice with the cut aligned with the jaws and shear the waste with a hammer and the chisel.

3. Drill an 8mm hole in each corner, and use a metal cutting blade in your jigsaw. Aluminium will melt and clog the blade so a slow speed is required to avoid heat build up. To avoid "chatter" you must hold the work firmly and support it firmly close to the cut. Cutting down between the jaws of a workmate will do if the jaws are close together, but press the jigsaw down firmly. Make one cut to each hole along all sides in a line. You will need to cut back into each corner hole to get the corners square (meaning if you start from 1 hole along side one, you need to turn around and cut back the other way into the corner.

I've done it and compared to buying a dash panel with loads of switches it is much cheaper, plus you can upholster it after to match whatever. If you upholster, I suggest you get some very thin fleece or 4mm foam glued down under first, this allows the switches to press in slightly and improves the appearance.

Why not do an entire new dash board panel? You can put all your instruments in as well in one smart new panel. Just mark up wires before you disconnect instruments, you don't want to start the engine with the bilge pump switch!
 
[ QUOTE ]
Cheers, the problem with this kind of answer and this is not disrespectful, there are hardly any left who will do stuff for the man in the street. When I was a kid I could wander around the local estate and get all sorts of small jobs done, now it is all the equivalent of B&Q engineering around here.

[/ QUOTE ]I know what you mean.... as a one-time car nut, I spent hours trying to find places that would do little one off jobs.....

The 'bolt tightened punches' described above sound like just the ticket though....

Youre right.... PBO is marvellous!
 
Unless you are prepared to spend some time marking off and cutting with a piercing saw using a jewelers bench ( Piece for wood with a "V" cut in one end) then I suggest you look in Yellow pages for a firm speciallizing in laser or water cutting, not cheap but a 1st class job.

If going down the saw route make sure the throat is deep enough for the material and use a 64-78 TPI piercing blade NOT a Fret blade, B&Q type shops will not sell the blades, somebody like Tracy Tool of Dartmouth the saw may be found in most good model shops for around £8 and the blades about £2-3 for six,I trust you find this helpful.
 
Alloy is fairly easy to cut with sharp tools.

Use parafin to lubricate the drilling.

You can cut very clean 22mm holes with your drill using a hole saw.

Do not push too hard and cut with a backing piece behind.

I have just finishing making a new instrument panel using slightly different material from you. It has between 30 and 40 holes in it.

I had to cut out a series of 10 x 30mm holes for switches on laminated fireplace hearth formica type material.

I did this by drilling undersize then using a black and decker power file.

For the larger holes I cut just undersize using a jigsaw then used the power file.

Although I was using a different material, I have also used the same technique when fitting out an alloy mast.

Everything was masked well and all the lines were marked on the masking tape.

I also used a centre punch before drilling any holes.

Not an impossible task just be careful and don't rush things.

Ihave a bench drill but didn't have to use it.

Iain
 
Why not drill 3, 8mm holes in each marked rectangle to form an infinaty shape and then file the holes out to your required 30x10 retangle, it would be quite easy on 1.5/2.5 allu especially with a course square file, and would be a hell of a lot cheaper.
 
I have never been impressed with those square with round hole ones, always very proud of the surface and I imagine in a couple of years you find the hole panel slightly out of line.

I really like the look of these hole punches as I imagine I will be able to do the whole job without that whoooops scratch right down the front of the panel, or even a mini one that as I did the job I will see every time I look at it.

the actual back dimension for the standard 16A switches I am using is 27 x 11 but considering the plastic spring clips on them will need a slightly larger hole. RS sell a punch that is 27.2 x 12.2 so I imagine it might even be made to coincide with the switches.
 
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