[m1abrams]

I have read a few howto's online on cutting square holes into metal without the use of a CNC. I need to cut one for an IEC and just wanting to get as many ideas as possible.

This is a source for a few methods: makezine.com: Make Square Holes in Aluminum Sheet Metal

So how have you guys done your non-circular holes? Has anyone tried using a rotary tool (Dremel) with a cutoff blade?

Is a hand nibbler a good choice? Would you purchase one to do the job because it is that much better than the other methods?

 

[kuroguy]

I've drilled holes at the corners and played connect the dots with a scroll saw. not pretty, but the IEC socket covers the ugly parts and looks good when installed.

 

[Pars]

The Greenlee punches are expensive, and I'm not sure you can get one for every hole you need to make. How thick is the material? I've used a nibbler tool from Ratshack, followed by filing for mine and it works pretty well, though tedious. I don't have a decent Dremel tool so can't comment on how one of these with a good cutoff bit would work. For stuff thicker than my nibbler will handle, I have used the drill a bunch of holes around the periphery and then file the edges. Tedious as well, but works.

 

[TimJo]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif I have used the drill a bunch of holes around the periphery and then file the edges. Tedious as well, but works.

That's been my technique if doing 100% by hand...

In aluminum, it goes pretty fast if you have a sharp file close to the same width as the cutout. The width of the file helps keep the lines straight.

 

[m1abrams]

Hmmm - thinking if I go the drill out method I may have to add a new tool to the workbench (Drill Press). Probably about time I broke down and bought one anyhow.

No one try the dremel cutoff method? Wondering if I would be able to keep the dremel from walking.

 

[CodeToad]

A table top mill would be a good addition to the DIY tool box. Keep an eye on the tool section of your local Craigslist.

 

[kklee]

Quote:

Originally Posted by m1abrams /img/forum/go_quote.gif No one try the dremel cutoff method? Wondering if I would be able to keep the dremel from walking.

I use the Dremel cutoff method. I use the Dremel extension cable, which is easier to hang on to and prevents the wheel from walking. It doesn't prevent you from breaking wheels and having that shrapnel flying about though.

 

[Coreyk78]

for an IEC socket I drill a round hole with a hole saw that is smaller than the socket and then work it out to square with files by hand. Sometimes I use a die grinder with a burr bit if I have a lot to remove.

 

[m1abrams]

Quote:

Originally Posted by kklee /img/forum/go_quote.gif I use the Dremel cutoff method. I use the Dremel extension cable, which is easier to hang on to and prevents the wheel from walking. It doesn't prevent you from breaking wheels and having that shrapnel flying about though.

Yep I do have the extension, that makes using a dremel much easier for lots of tasks. And I am well aware of the cutoffs throwing shrapnel, I learned to wear full face masks with those things

I just never used them for precise work.

 

[deltaydeltax]

Greenlee punches are the way to go. Unfortunately all of the ones I have are round. Or else, I'd be happy to rent you one to punch a rectangle. A punch definitely makes short work of odd shaped holes.

 

[MisterX]

I cover the the panel in tape, draw the hole, drill a line of holes around the perimeter of the hole, cut the gaps between the holes with a reinforced cut off wheel in the dremel or my shear cutters (depending on the size of the hole), smooth out the edges with a dremel #194 "cutter" and then finish it up with a file.
Makes a huge mess but only takes a couple of mintues.

 

[scompton]

I'm going to be trying my wife's scroll saw tonight. I have to buy a metal cutting blade on my way home from work.

 

[Punnisher]

Waterjet.

 

[kuroguy]

scroll saw tips: use a low blade speed and go slowly, wear ear plugs, let the saw do the work; use a very light touch.

 

[oneplustwo]

If you wait for the harbor freight sales, you can get a mini mill for not much more than a drill press. Of course, it's going to be rather limited in x-y capacity, but works well for this kinda case work. I've had mine for almost a year now and love it. (Don't get the micro-mill... the mini mill is much more machine for the money.)