cutting squares in hammond boxes?!

[blue_lu]

 So - I will attempt to build a stereo LA Light compressor in a larger enclosure - maybe a Hammond enclosure. So I looked around for some analog VU meters - and damn they are expensive (especially nice ones and easy to mount would be  SIFAM AL15, but its like 30 euros per PIECE!). So I shot myself some nice new VU meters from ebay and they arrived today. turns out I have no clue how to process the box to fit these right angle vu's.

How do you guys cut larger squares in a hammond enclosure?

thanks!

p.s.: I only have a hand drill.

[John Lyons]

Buy a "Nibbler" to cut flat/square holes.
Just mark your square and drill 4 corner holes.
You can also drill the entire hole with a series of small
holes around the perimeter and then use the nibbler
to clean up the holes once the main piece comes out.

[alparent]

This is what I do.
Drill all around the parameter line of your square hole.
After that I use small files to file away the remaining metal. The alloy of these boxes file away very easily.

[runmikeyrun]

Use a small T-square to mark the box you're cutting out, and be careful filing to make the edges of the box as clean as possible.  Also, the wider the file, the easier it will be to keep the edges straight.

[R.G.]

Mark.
Drill.
File.
or, alternatively to the last,
Nibble *and* file.

[blue_lu]

Alright, thanks for all the help! Off to buy a file, I guess. Anything specific I should look out for when buying (certain materials, etc.)?

[defaced]

For filing aluminum, the file material isn't really relevant, the cut style and tooth size that is.  You'll want a double cut for fast removal, and/or single cut for better finish.  Don't get a super coarse (like 1/8" teeth) file intended for lead.  Wiki has some pictures that will help: http://en.wikipedia.org/wiki/File_%28tool%29

[kristopher612]

get a dremel and the cut off wheel attachments.  mark, cut, done

[tiges_ tendres]

get a dremel and the cut off wheel attachments.  mark, cut, done

Don't forget eye protection!

[davent]

get a dremel and the cut off wheel attachments.  mark, cut, done

Don't forget eye protection!

(And you'll still need that file.)

[R.G.]

Nota Bene: Filing
Aluminum is a "gummy" metal to machinists, and it's problems are nowhere worse than in filing.

Little chunks of aluminum stick under the teeth and mar the work. This process is called "pinning" in the trade.

There are two ways to avoid pinning. Probably the easiest is to rub hard chalk into the file to fill up under the teeth. This keeps the bits from sticking so well. The other is to file only with a file which has been freshly dipped in oil. You'll still have to use something to get the few remaining bits of aluminum out, One way is with a brass wire brush.

[alparent]

Probably the easiest is to rub hard chalk into the file to fill up under the teeth. This keeps the bits from sticking so well.

Neat trick! I will try that next time. I usually stop often and clean my file with a file brush. But I will try this next time.

[R.G.]

You have to use the real hard chalk, not the soft spongy stuff they sell for little kids. True old-time school-blackboard chalk would be good, as would "railroad chalk".

[alparent]

"railroad chalk".

[John Lyons]

"railroad chalk".

You know, those tough kids that walk the rails, yet still need to play hopscotch
or write "I will not spit" on the blackboard when the need arises. 

[defaced]

Nota Bene: Filing
Aluminum is a "gummy" metal to machinists, and it's problems are nowhere worse than in filing.

Little chunks of aluminum stick under the teeth and mar the work. This process is called "pinning" in the trade.

There are two ways to avoid pinning. Probably the easiest is to rub hard chalk into the file to fill up under the teeth. This keeps the bits from sticking so well. The other is to file only with a file which has been freshly dipped in oil. You'll still have to use something to get the few remaining bits of aluminum out, One way is with a brass wire brush.

With a typical file, yes, this is all absolutely true.  However, files specifically for aluminum (and will likely work on other soft metals, brass for example) do exist.  The biggest difference being the size of the teeth/coarseness.  http://www.google.com/search?q=aluminum+files

That said, still don't know why anyone would want to file a hole.  Royal pain in the...  I'd opt for a small diameter burr if I had to do this in aluminum.  1/4" dia clog free burs at 10 bucks on mcmaster. 

[Maik]

I do those things with a jigsaw. Works perfect

[alparent]

That said, still don't know why anyone would want to file a hole.

The only reason we are talking about filing this hole.........is because we want it to be square.

[jefe]

Dremel with cutoff wheel, then file.

[defaced]

That said, still don't know why anyone would want to file a hole.

The only reason we are talking about filing this hole.........is because we want it to be square.

The statement was alot more rhetorical than you're reading it.  Obviously we want a hole with square corners.  That's a given.  What I'm getting at is there are more than one way to make a hole with square corners, of which, filing is probably the least efficient and most annoying way to do it.  So why would anyone want to do it that way?