Best way to cut an IEC inlet shaped hole in a Popely case?

Hi Guys

I've got a few of these and can feel a Hicap replacement project coming on.

Got all the bits to build th first one and the only thing I haven't attempted before is to cut out a big rectangular hole for a fused switched IEC inlet.

I'm considering doing it by the cheating method of cutting out a c shaped hole at one edge of the case, which is probably a whole lot easier but a bit of a bodge. I could do that by just making two hacksaw cuts and work hardening out the middle bit with a pair of grips.

Is there an easy way to do it properly and accurately without any special tools? I know I could drill out lots of holes and join them up and file the edges square but that's a bit of a fag.

 

Use a hole saw,drill a hole with it up to the edges of the rectangle marked out,should be able to do 2 holes,then file the corners flat. Job done.

 

Masking tape, drilled corners, 38mm Dremel cutting wheel and a small file to even it off.

 

Hole saw is a good approach. Most useful tool for such jobs would be a Dremel...

 

Hi,

Chain drilling is the best way, a series of 3mm or so holes close together near the outline cut the webs with cutters or fille with a needle file, then file square.

Pete

 

I usually mask, mark the shape I want, drill in the middle then use my step drill to enlarge.. Then jigsaw with metal cutting blade then file to finish. Neat holes.

 

I've done this exact task task a number of times to these very cases. I've chain drilled them - which works OK but takes ages - I've also use a Dremel disc cutter and this works well. However, the easiest was to use a coping saw (yes, one intended for wood) - cuts aluminium very well indeed (you have to drill a pilot hole of course). A step drill works well for round holes. Neatly mask the back out first with masking tape and neatly draw the shape you want in either biro or fine liner (pencil isn't so easy to see and an rub off). You will need to hold it in a vice (with soft jaws).

 

Yes coping saw was another thought, but having recently had a lot of trouble making a coachbolt head size square hole in a stainless steel saucepan, for which I resorted to that very method I was a bit unconvinced by it, but if you say it works I'll give it a go.

 

Cutting stainless steel and cutting aluminium are two very different things (the blade is too coarse for SS). Trust me, a coping saw works very well on Andrew's cases - I did one only a few weeks ago - took five minutes and after a light file the IEC socket was a perfect fit.

For your saucepan I would have drilled a hole and then used a flat needle file to square it off.

 

Yep, coping saw is the best method I've tried. Just take your time, coping saw blades are inclined to wander.

 

The classic metal working way to do this would be to use a jeweler's saw. I have one somewhere. Similar to a coping saw but with finer control.
Blades of extreme thinness can be had and can change direction easily, unlike hacksaw/coping saw blades.
That said, they are usually used on non ferrous metals, so I don't know how they'd cope with steel, especially stainless.

http://www.amazon.co.uk/s/?ie=UTF8&...vpone=&hvptwo=&hvqmt=b&ref=pd_sl_8gx3y2qab3_b

Mull

 

Yes, I agree, I have also used a piercing saw; but in this case, the case is made of aluminium and easy to cut with a standard coping saw.

 

OK.

May I also re-introduce an old method which I suspect is rarely used these days?

A good, sharp cold chisel.

So long as the work can be fully supported on an anvil of some sort, intelligent use of a chisel can make quick work of most things up to mild steel.
I would drill out corners first and finish with a file.

Mull

 

Agreed, a really sharp chisel's a good way too - certainly the fastest.

 

Little wonder...

 

fastest way would definitely be a lightsabre.


or perhaps a square sheet metal punch.

http://www.lawson-his.co.uk/scripts/products.php?cat=metal hole cutters

 

during may apprenticeship in the 70s A cold steel chisel is the way I was taught in sheet metal work, you had to go into the Blacksmiths shop first though and forge you own chisel out of bar stock followed by quench and temper in whale oil. It works but you do need a really solid piece of steel underneath it and a nice sharp chisel or you'll end up distorting the back plate.

My own preference is to drill the 4 corners and put a bigger hole in the middle, use a jig saw with a sheet metal cutting blade between them and then finish with a file.
A high speed air saw is better than a jig saw as well if you have one http://www.harborfreight.com/high-speed-metal-saw-91753.html
http://www.amazon.com/dp/B0013WEAO6/?tag=pinkfishmedia-20

Alan

 

Not an IEC in a case, but a door in a wall; my builder must be on the same wavelength..

 

He forgot to drill a door handle....
Get the drill out and add a door handle for him...