Make my own enclosures from aluminium sheets?

[slashandburn]

Hey again. So I'm digging back in but starting to resent spending £4 to £10 on every enclosure.  I've tried going the Cheap Chinese Hammond Clone route a few times but got hit with a few boxes weird finishes (zinc plated I think) and in any case I really hate the delivery times.

I've seen some here making their own boxes with sheet metal and wooden blocks on either side and they look great (sorry, I forget who,  it's been a while since I last here!). Pricing up aluminium sheets  has me thinking this approach could be worth the extra effort. I do however have a few questions before I jump in and cause myself an injury.

Aluminium sheet type and thickness?  I'm guessing 2mm would be a good ballpark to aim for. Other than that I have no idea what I'm shopping for.

Cutting? What's the best way to approach this?  The most rudimentary tools that can be used end up with a clean and efficient cut?  Good old clamp and hacksaw? Jig?

Shaping the box? This is the part I anticipate botching the most. Metalwork isn't exsctly my thing but hey how hard can nice, straight 90 angles be? Right? Right?  Just draw a line, line it up in the vice and whack it with hammer. Easy, right?  Anyway, seriously, how do I bend it into shape without it ending up looking like the raffle car in Father Ted?]the raffle car in Father Ted?

Any hints or tips would be appreciated!

[antonis]

Aluminium doesn't like bending..!! 

[greaser_au]

Hand bending enclosures?    You wanna be talking to my fellow countryman and all-around nice bloke,  duck_arse

david

[diffeq]

As R.G. once pointed out, there are aluminium boxes sold by some metal suppliers which are basically long rectangular tubes with various thickness and sizes available.

So you won't have to bend, just cut the required length of a tube, cut the bottom out and add cheecks of wood or metal. They are cheaper too, I saw 6 meters of tube for around $30-50

[Juan Wayne]

You can bend aluminum, just don't go too crazy with sharp angles or it'll break. Steel is much more forgiving, but also heavier, so you would need thinner sheet, just not too thin.

But hell, I've done it, there's some very basic bending tools you can use. However, unless you're going for a very custom build like it was in my case, it's not worth all the extra work and considerations you must make, not to mention in the end, you won't save that much compared to mass produced, dedicated enclosures.

I've tried electrical enclosures, I even went as far as making my own enclosure design and having someone sand-cast the rough aluminum boxes that I then milled and finished. If you're not stuck in an obscure South American hole and have perfectly finished Hammond boxes readily available, it's not worth it.

[duck_arse]

steel. get yerself an old PC, like a mini-tower when they had the one-piece, U-shaped over cover. it will be the right thickness, comes coated w/ epoxy paint of some sort, probably cost you nothing this far, you're already ahead.

if'n you don't have "the right" tools - get an electric jigsaw (sabre saw for PRR) with a metal cutting blade, and some clamps and some straight edges. measure and mark (dark felt-tip near-lines, then scribe thru to the metal accurately), cut, file, sand the edges square. otherwise, hacksaw and cutting oil. and clamps.

find some large lumps of wood, 70 x 45mm pine is a start, and go to town with the bending. but first do it in cardboard, to work out which is drapes and which is plugs.

there was a thread, had pictures too .....

[Mark Hammer]

I've made a few, though with Hammond (and look-alike) boxes so cheap, and arriving powder-coated, the motivation to do so again is very low.

One thing I will dangle in front of you is to not underestimate the value of using wooden sides.  For instance, PAiA used to use a wood/steel combination for some of their chassis, and they were quite sturdy.  Ultimately, what you are aiming for is something whose size can accommodate the boards and number of controls you want/need, but has the sturdiness to "survive" foot-stomps.  Thick aluminum can certainly survive that.

[diydave]

Aluminium sheet type and thickness?  I'm guessing 2mm would be a good ballpark to aim for. Other than that I have no idea what I'm shopping for.

I get big sheets (100 cm x 50cm - 1mm thick) from the local hardware store. 2mm would be better, but less easy to come by.

Cutting? What's the best way to approach this?  The most rudimentary tools that can be used end up with a clean and efficient cut?  Good old clamp and hacksaw? Jig?

A simple stanley knife + a metal ruler

Shaping the box? This is the part I anticipate botching the most. Metalwork isn't exsctly my thing but hey how hard can nice, straight 90 angles be? Right? Right?  Just draw a line, line it up in the vice and whack it with hammer. Easy, right?  Anyway, seriously, how do I bend it into shape without it ending up looking like the raffle car in Father Ted?]the raffle car in Father Ted?

A little bending brake. Got my inspiration from here:
http://runawaybrainz.blogspot.com/2011/11/diy-how-to-bend-aluminium-easy-way-with.html

[R.G.]

The steps in bending aluminum - or any sheet metal - into enclosures go like this:
1. Read
2. Read
3. Read
4. Read
5 - 12: Read
13. Try some test pieces based on what you've read.
14 - 20: Try some more test pieces and practice.
21. Try a first real attempt.

The bend-ability of sheet metals depend somewhat on the material, but even more on the state of temper of the piece of sheet metal you're working. "Temper" can be thought of as the degree to which heat treating and/or work-hardening has hardened and stiffened the piece of metal.

Some of this is metal- and alloy-dependent. Low carbon steels can't be heat hardened at all, high carbon steels can be made into files and springs. Pure aluminum is quite bendable, and can't be hardened to then withstand bending very well. Aluminum alloys have dramatically different properties of hardening and resistance to bending, as well as the tendency to crack when bent. Here's a good quick overview of the various aluminum alloys that are available in the market.
https://www.onlinemetals.com/productguides/aluminumguide.cfm
You probably should work with 5052 or 6063 alloys. Fortunately, these are the most widely available in small quantities. 2mm is a reasonable thickness, although up to 3mm could be worked.
There is a book in the Model Engineering Workshop Practices series on working sheet metal. It is very informative, right down to exactly how to hand form the stuff at the level of where to hit it with what hammer.

Bending with a brake is probably more what you have in mind. The two problems to be addressed there are (1) where to get a brake that's usable and affordable and (2) bend allowance. Bend allowance is tough. When you bend a metal sheet, the bend has some radius, and the metal is stretched on the outside, compressed on the inside. This changes the length of the piece appreciably. So when you cut your piece, you have to allow for what change in dimension will happen with the bends you later put into it. This can get complicated.

[mac]

I have tons of this, galvanized steel sheet, C type in my country,



You can make square boxes of two parts.
If the width is W then make the lenght of the top side L=W.
If thickness is T then you need to cut the bottom side of lenght W-T.
You need to remove parts of the C too. See below.
Then drill four holes, sand, and that's it.
If you ever played Tetris you'll figure it out





Warning: You'll need an angular grinder or another e-tool to cut metal. Your fingers are at risk.

mac

[EBK]

This thread keeps telling me, "Eric, you're fully licensed to operate a Hammond die cast enclosure and you should just be happy with that."   

[Rob Strand]

Pricing up aluminium sheets  has me thinking this approach could be worth the extra effort.

It's all do-able. 

It boils down to how many you intend to make, how much you want to spend on tools.  How much time you want to spend getting your process right.  You will waste material for sure and for some time in the future until you get the process right.   Also, it depends if you can buy the material at a good price.  Some vendors want more for a small piece of crappy 1mm aluminium sheet than they do for a finished enclosure.

I'm always impressed how good a job people do on forums like this with how little resources.  Professionally I'm in a state of disbelief by the poor work done by professional sheel-metal shops who have a workshop full of the right tools - ignoring the fact that it's their profession.  All the points RG and others have brought up are totally valid.   I know a guy that builds a lot of prototypes for companies.  He bought a small bender.  It does make life easier but it also has limitations in terms of sizes, widths (and some shapes are not possible as the "work" hits the tool).

Some commercial enclosures only use 1mm (!).  The 2mm stuff is much better.   Going too thick makes life difficult to work with.   Folding long narrow edges with 3mm sheet and bits of wood might not be so successful.

[Rixen]

you can make a half decent bending brake, but for cutting that thickness without a large (metal) guillotine you will need to cut with a fine toothed saw, and then spend time with a file straightening and cleaning the edges up- because they will burr.

[PRR]

Your fingers are at risk.

This.

Many of my best gashes are from raw sheet-metal edges.

That's before the fact that sheet metal does not like to bend, or bend square, or into a box.

I bent very thin-gauge aluminum flashing over my new shed roof. Came out so bad I went and got some trim to go around the edges. Did a little bleeding, and am amazed I didn't cut myself worse.

[diydave]

It's all do-able. 

[Electron Tornado]

Something on the subject from Uncle Doug:

[R.G.]

This link:
https://www.amazon.com/Sheet-Metal-Work-Workshop-Pratice/dp/0852428499
offers you a really good intro to sheet metal work (and thinking about it) for US$10-$15. If you're not in the US, they're even more available in the UK, where the series originated. You'll save the purchase cost in the first batch of metal you don't waste.

[cab42]

I use pretty much the same method as Dave, and have built a bending brake almost the same as in the link.

I use a jigsaw for cutting, though. Maybe I should try a stanley knife instead, seems more convienient. Especially when not having a workshop, having to do it outside. Not often an option in the winter.

BTW, check out some of Dave's builds in the pictures thread for examples.

Edit: Hey, it works!! I just tried to cut a piece of scrap aluminium with a stanley knife. So easy.

[Rob Strand]

Something on the subject from Uncle Doug:

Nice video.

I like his cutter.   You do get some waste.  I wonder how well it works when you cut close to an edge, and the minimum width of metal you need on the non-work side.

[amptramp]

In one company I was at, the cost of test fixtures and controllers (which were one-off pieces of equipment) was getting out of hand, so they had a company make up an extrusion that would hold two pieces of aluminum at right angles.  The basic shape was an "L" but each side had outer and inner pieces to hold the aluminum sheet in.  It was a double angle extrusion like the second one except the outer part was shorter than the inner part so the panels could be screwed to the inner part:



We could build boxes of any size that way.  But why bother?  There are huge numbers of surplus modem housings made as aluminum extrusions so unless you are going into production, use one of those.