Cutting 1.2mm Copper

hi

I’m wondering if anyone can help? I’m wanting to cut lots of 80mm x 30mm rectangles out of 1.2mm copper which would be the right tool for this? I’m currently using a handsaw but I’m sure there must be a better alternative? Also could anyone recommend a tool for cutting 30mm discs out of 1.2mm copper? Thanks

Hi Heidi

For the rectangles I suggest contacting a local sheetmetal works and getting them to guillotine them for you.

For the discs I can only suggest a chassis punch or similar probably available from RS Components.

Roger

Heidi For the discs I would try a holesaw without the pilot drill, in a drilling machine

Roy

Heidi Crocker:

It would be helpful to know what equipment you have available by way of hand and machine tools and, if you are looking for practical assistance, to have some idea of where you are. As you have started with a handsaw, I assume that "lots" does not mean hundreds or more.

The problem with hand and bench shears is avoiding distortion of the workpiece; the chassis punch is also likely to distort the resulting blank.What is the state of the copper - hard or soft - and what sort of finish do you need on the cut edges?

Hi Heidi, how many is "lots"?

Agree with the guillotine approach - either subbed to someone with the facility to supply you the banks cut to size, or cut them yourself. For moderate quantity I'd go with a bench guillotine (bench shear). ArcEuro do something they call a bench shear which is a useful sort of gadget for this kind of work. There's a knack to getting it to cut along the line you want, rather than it wants. but it'll certainly do the job. Quick and effective, reasonably flat pieces.

If you've got hundreds to do buy a small treadle operated guillotine or better still buy them ready cut.

For the circles, I assume you want the circle not the hole. If so a chassis punch used in a fly press (no pilot hole) will eat this no problem. The contour on the end of the sheet metal punch will distort the cut circle so it will need flattening as a second operation.

If you just want the hole then a chassis punch ["Q-Max cutter"] used in the normal way with a pilot hole is a bit laborious but simple and effective. There are hydraulic versions of the same process which are a bit quicker and a lot less effort.

Alternatively a proper fly press punch and die (flat ended) will give you a better (flatter) result. You could bump these out as fast as you like.

If you go the flypress route, 80 x 30 mm as a simple rectangle in 1.2 mm copper is well within the capabilities of a middle sized flypress as a punch tool, but it would mean getting a rectangle tool made for the size. But once you've got the tool, you could bang these out in style. All depends how many you want, and how much is cost effective to invest in getting to the desired result.

Hope this helps, Rgds Simon

Edited to evict a yellow winky face

Edited By Simon Williams 3 on 30/01/2018 12:28:49

For the discs try pressure turning blanks on a lathe.

Cut the copper sheet into squares, and take off the corners.

Mount a piece of steel, Ali, Brass into the chuck that's smaller than the dia of the finished part. Face it off so it runs flat to the face of the chuck, then use double sided tape on the face of the blank. Now center your copper blanks on the blank in the chuck. You could use the cutting tool as a gauge to find a rough circle.

Now a spare piece of Steel or Ali is put up against the copper with double sided tape again, and the live center is brought up and presses the whole lot together.

Now take light cuts to the diameter you want, once you have the right diameter, zero the dial so you can repeat the process.

As for the square stock a band saw would make light work of cutting it and a bench mounted belt/disc sander to finish to size.

Have you thought about getting a reciprocating saw whilst clamping the sheet?

No connection to this company, just a selection to look at.

**LINK**

Michael W

It does depend on which bit is important, the disc or the hole. Many of the methods described so far assume that what is wanted is square, or round, bits of copper. What if we need rectangular or round holes - as we do in a gasket, for example?

A large number of holes might justify a punch and die, set up on a fly-press or similar, whereas two or three could be done with a piercing saw (depending on how far the hole was from the outer edge). For a middling number, you might think of laser cutting, but it won't do with copper - it is too good a conductor. In this case, 'water-jet' might be the best option. In all these cases, it would be easier to do the cutting if the sheet was hard-rolled, and then, if necessary, annealed to soften it. Unless, of course, it was wanted stiff rather than floppy.

I hope this helps

Cheers, Tim

This is perhaps a little exotic, but for cutting circular boiler tube plates for gauge 1 engines (copper circles with holes of various sizes for flues) I use my Sherline CNC mill. It works beautifully and would certainly do 30mm circles. There's none of the distortion that a guillotine or flypress might introduce. I clamp or glue the copper to sacrificial bits of MDF as backing pieces. Of course it could also do your 80x30 rectangles too, and any other shapes you need.

The capacity of a Sherline is pretty small, so no good if you need big pieces done, and depending on the cutter the kerf can be pretty big so there is material wastage compared to a water jet.

Adrian

Edited By Adrian Johnstone on 30/01/2018 18:48:48

I had a similar problem recently. I have one of those multi purpose rolls, bender, guillotene machines but that struggled with the thickness as did tin snips and my bandsaw which is usually great for cutting out pieces from brass, steel and copper sheet was not suitable in this case. As a last measure I rediscovered my angle grinder I bought many years ago, with a bit of care it did the job in no time.

As with all problems like this, its horses for courses.

Bill D.

I spend most of my days cutting copper in one form or another, If its a repeating flat shape (boiler end plates for example) it is a complete no brainer to get it laser cut, you will probably even save money this way as copper sheet is expensive and the laser can cut so as to leave the very least amount of waste. Get a coulpe of quotes and be a convert.

A choice of methods to produce these parts has been offered, one thing to bear in mind is the edge condition varies with each method and if a clean square edge with no distortion is required you may need to do further work.

Mike