cutting square holes in hammond enclosures?

[caress]

curious about people's methods...

i've thought of the obvious things like a nibbler (not sure if that would work on a standard hammond enclosure, though...) and filing (though very tedious...).
any thoughts, ideas, musings...?

[jalien21]

any time i've ever cut a square hole out of a metal box, i've always done it with the cut-off wheel for a dremel. works pretty well, actually. takes a small amount of getting used to, but once you get the hang of it, you can get really good results. only problem is that there is a minimum length that you can cut that depends on the diameter of the wheel- shortest line i can cut is usually like a half-inch. maybe there's a better dremel attachment out there that'll let you cut shorter lines?

[Nitefly182]

I searched nibbler here the other day and people said it was possible to use one on a hammond enclosure but that their hands were aching for days after.

[km-r]

i once drilled a hole then filed the sides but my wrist ached for many days after that...

maybe strong ferric chloride and masking tape?

[krachbox]

drill holes, use a coping saw, file. That's how I would do it.
hmm, lasercut it? 

[Andi]

Dremel with a suitable router bit, router base and a template to work against.

Or, better, a punch of the correct size. Drill one hole to centre it and off you go.

[woolley]

i drilled a few holes and used a square profiled file. took a bit of time to get it all square but it wasn't too bad. no aches to report.

[Ripthorn]

All of my enclosures have been of wood and I have used a mortising chisel.  Not sure that helps with metal, though.

[R.G.]

The accepted wisdom in the amateur radio community is to either drill most of the area out (small openings) or chain drill around the edges, then use a file to smooth the sides. It is a big help to mark the square edges carefully first.

As with any hand-metalworking, it is good to protect the surface anywhere you don't want to mar it with masking or transfer tape.

[Mark Hammer]

My dad was a tool & diemaker and machinist most of his life, so I picked up a few things working for him on weekends.

What you really want is what is referred to as a milling machine; basically the metal equivalent of what a router is for wood, except that the distances are often more precise, the depths and lateral movements smaller.  Plus, one generally keeps the bit stationary and moves the object to be machined, as opposed to moving the router around the wood.  The bit moves at a much higher speed than normally occurs for your average drill press.

In some respects, the optimal homebrew solution would be to use a drill press with a higher high speed, and a milling bit.  Since the drill press can't move around, you'd want to move the chassis around, while securing it with a drill-press vise.  You'd still end up with round corners, but once you have your rounded rectangles milled out, you can tackle the last little bits with a flat file for corners.

[blueherdim7]

I have used a unibit to drill a hole aproximately the width of the square/rectangle.  Then used a dremel high speed cutter bit to cut the circle into a rectangle.  I used this dremel bit  http://www.lowes.com/lowes/lkn?action=productDetail&productId=94700-353-125-03&lpage=none  and was very happy with the result.  I did it to cut a an opening for a slide switch in a Boss FA-1 clone I built.

Jon

[axg20202]

There's also the option of Q.max sheet metal punches, but the square/rectangular ones are expensive. If you know you will be using it a lot it is worth the investment because the holes they cut are perfect every time and take minutes to do. I have several Q.max punches (though not the square kind) and they have been used hundreds of times and are still going strong. For perfect, burr-free holes they can't be beaten. You just drill an accurately-placed pilot hole for the bolt, thread the pieces together through the hole and tighten with an allen key until the hole is cut. They are designed for sheet metal, but work really well on aluminium enclosures and the thickness is no problem.

[Mark Hammer]

Are there brands/sources of Hammond-style boxes that have thinner (but still acceptably thick) walls that would handle punches better?

[m-theory]

Are there brands/sources of Hammond-style boxes that have thinner (but still acceptably thick) walls that would handle punches better?

Yeah, I believe the chinese boxes are thinner walled.  I've used them for a couple of A/B pedals, but I can't recall offhand where I got them...maybe effectsconnection.  Still might be a challenge getting a punch to work, but surely easier than with a Hammond. 

I've wanted to build something with slider pots for a long time, just for the uniqueness factor, but never could wrap my head around the problem of cutting those slots out.  I can see where a routing bit of some sort on a drill press might work, as would a dremel with a cutoff attachment (hate those exploding fiber discs, personally...the diamond wheel is infinitely safer), but making them straight would be a challenge.  Do-able, but not without significant care.  Now that I've got a drill press, I wouldn't mind giving this is shot sometime.   

[davent]

Here's a tutorial on using a router for rectangular holes in aluminum chassis. Just scroll down the page a bit to get to it.

http://www.silvatone.bravepages.com/18%20Watt%20Lite%20II/Build.htm
http://www.silvatone.bravepages.com/Tutorials/PT%20Cutout.htm

I use a Dremel with cutoff wheels to connect holes drilled in the corners then file to finish.

dave

[scratch]

while looking for 'milling bits' in Google (thanks for that Mark!) ... found this ...

http://www.makezine.com/extras/15.html

now I'm also looking for those Q.max punches ...

[ilcaccillo]

A Jigsaw can be useful also.


I also like the idea of :

" maybe strong ferric chloride and masking tape? "

[yeeshkul]

The accepted wisdom in the amateur radio community is to either drill most of the area out (small openings) or chain drill around the edges, then use a file to smooth the sides. It is a big help to mark the square edges carefully first.

As with any hand-metalworking, it is good to protect the surface anywhere you don't want to mar it with masking or transfer tape.

That's what i do all the time - an alcohol-based marker to draw the rectangle first, drill as many holes as possible and some file to give it the shape.
Slide switches are durable, but pain to install .

[mnordbye]

Here's a tutorial on using a router for rectangular holes in aluminum chassis. Just scroll down the page a bit to get to it.

http://www.silvatone.bravepages.com/18%20Watt%20Lite%20II/Build.htm
http://www.silvatone.bravepages.com/Tutorials/PT%20Cutout.htm

I use a Dremel with cutoff wheels to connect holes drilled in the corners then file to finish.

dave

Anyone know where to get a drill/router bit like this?

[frequencycentral]

OK, not a square hole. But I'm a fan of using a couple of files, a lot of paitence, and a lazy Sunday afternoon.