# What tools/methods to cut square holes in an enclosure?



## de93 (Feb 28, 2011)

I build panels and typically for mounting HMI touchscreens, fans, etc. we drill some 3/8" holes and use those as entry points for a jigsaw blade. Then we clean the cuts using hand files. It's time consuming, but does the trick for larger holes. The mounting fixtures for Hoffmans fans and other devices covers the imperfections in the hole.

Now, I'm needing to make some small, precise holes about 1x1.75" and even smaller for various connectors. The holes are too small to be done with our drill/jigsaw method, and the finished hole looks awful. These connectors don't have mounting fixtures that will hide the cuts either, so they need to be even more fine and precise than usual.

I was looking at getting an electric die grinder/rotary tool with some steel-cutting blades, but it still seems like I might have problems with precision and working with smaller holes that the blades might be too large for. This tool would also be better for grinding the edges instead of using hand files.

I looked at some nippers, but that doesn't seem practical either. What other options haven't I been able to find?


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## RePhase277 (Feb 5, 2008)

Use a Dremel with the router base attachment and shallow passes with a carbide cutter. It may take a while but it will be slick.


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## mattsilkwood (Sep 21, 2008)

You can get KOs for just about any standard hole, square, rectangle, whatever. They are expensive though.

What I do if it's one we don't have a KO for is I will mark it out in pencil, then put masking tape right up to my line (on the outside of my line). 
Then I drill a couple acess hole in the corners and cut them out with a jigsaw on SLOW speed. You can cut right up to the tape and it gives you a laser straight line. Just be sure you don't try to go too fast or you will 
f##k up every time and some of those components only have a couple mm of play.


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## Stab&Shoot (Aug 23, 2011)

A fein tool may work. If it's a square hole.


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## Lz_69 (Nov 1, 2007)

Maybe some square or rectangular knockout punches? They are expensive as hell but one might be the right size for you.


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## user8640521 (Jan 17, 2009)

de93 said:


> I build panels and typically for mounting HMI touchscreens, fans, etc. we drill some 3/8" holes and use those as entry points for a jigsaw blade. Then we clean the cuts using hand files. It's time consuming, but does the trick for larger holes. The mounting fixtures for Hoffmans fans and other devices covers the imperfections in the hole.
> 
> Now, I'm needing to make some small, precise holes about 1x1.75" and even smaller for various connectors. The holes are too small to be done with our drill/jigsaw method, and the finished hole looks awful. These connectors don't have mounting fixtures that will hide the cuts either, so they need to be even more fine and precise than usual.
> 
> ...


you say you build panels, and so i am going to assume this is mostly
done in a shop instead of the field.

this is going to sound like overkill, but it isn't.

plasma cutter. i've got one by miller that is the size of a toolbox,
that will cut thru 3/8" stainless.

and make yourself some permanent templates, out of 1/4" tempered
hardboard, or aluminum, or whatever you wish. take your time and
make them nicely.... put crosshairs on them, and edgemarks, etc.
do them for conduit as well.

the tip of my plasma cutter is 1/4" in diameter, so all mine are 1/8"
larger than what i want to have as an opening. if the opening is
far enough from the edge of the panel that you can't clamp the
template, use a couple pieces of duct tape, etc. to keep it from 
moving.

if i have something really weirdly shaped, i draw it in autocad,
and take the exact outline, do an offset an eighth inch on either
side of the target line, and i end up with a tracing line on either
side of the target cut line, then i tape the paper to the sheet of
steel, and trace it with the plasma cutter. you can cut right thru
the paper, and it doesn't catch fire and burn, just singes away
a little bit.

all you have to do is cut out a 4" x 7" panel opening in 12 guage
stainless steel in about a minute, one time, and you'll not care
what that thing cost.


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## de93 (Feb 28, 2011)

FulThrotl said:


> you say you build panels, and so i am going to assume this is mostly
> done in a shop instead of the field.
> 
> this is going to sound like overkill, but it isn't.
> ...


Yeah, most of my work is done in a shop. I looked at some online videos of plasma cutters, and that would be such a useful tool to have here. I'll do some research and bring the idea to the boss, since it has a sizable price tag. For now, I'm going to probably get a rotary tool and some quality discs to get the job at hand finished.

Thanks for the suggestions... I'm still all ears to more too!


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## nolabama (Oct 3, 2007)

I have built panels like you are describing. We used a plasma cutter and cleaned em up with a belt sander.


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## JRaef (Mar 23, 2009)

Plus 3 on a plasma cutter. I had one when I owned a panel shop. When I went to work for a manufacturer, they were using jig saws and cutting disks. Took the stingy owner to a trade show one day to watch a plasma cutter being demonstrated, he pulled out his checkbook on the spot and bought it, never looked back. Rent one and have the boss watch, it's a no-brainer.

What we did was that for every cutout that was going to be more than a one-off, we first cut a metal template out of scrap aluminum* that was bigger than the required hole by the width of the tip of the cutter. So when we went to do the real one, we placed the template down on the panel, sucked it down with big strong magnets (went through the aluminum to couple with the steel) and buzzed out the hole. 5 minute process, including layout.

We actually used plywood for a while, the plasma cutter is so fast it barely scortched the wood, but it did and we had to eventually remake the template, which we did in aluminum the second time.


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## John Valdes (May 17, 2007)

I have seen punches for almost any size square hole unless it is bigger than 1/4" din. I have never used a plasma cutter. I guess if you are building panels for a living, it might be worth the cost.
Tape and jigsaw is what I have always been forced to use. It sucks and you need Hoffman touch up paint on hand.
Anyone using Schaefer enclosures?


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## Jlarson (Jun 28, 2009)

Grinders, plasma torch, jig saw, sawzall, whatever it takes.


One of our larger accounts uses their CNC water cutter to do all the panels for their projects for us, best thing ever by far.


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