Cutting Out Enclosures by Hand

April 05, 2021

Layout the electrical enclosure.

The first thing to do is to lay out the enclosure. You don't want to cut the holes in the wrong side!

Machined drill fixture.

In this case, I use a machined drill fixture made from some scrap. This particular fixture has multiple cut out patterns on it.

The fixture has all through holes and the tangent holes for the 4 corners of the rectangle cutouts. I mark my first hole, drill it, then attach the fixture using a cleco. I align for the angle, drill a second hole, and cleco. Now the fixture position and alignment is set. I will do two more holes and clecos to prevent any sheet metal sag.

Now I can confidently do the rest of the holes. This saves a lot of time with the layout and eliminates the drill walking on start.

Grind rectangles and tap holes.

Then I remove the fixture, and draw my tangent lines for my rectangular cut out. I tap the holes first while the rigidity is still there. Then I grind the rectangle.

Finish corners with hacksaw.

I finish the corners of the rectangle with a hacksaw.

Final cutout.

The finished product needs to be cleaned up and deburred with a file. This takes the most time. It is never going to be as clean and consistent as a CNC laser cut.

Finished Product.

Luckily the installed device hides it!

If you need some design and build help on your project, let us know!

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Written by Bill Schnoebelen who lives in San Francisco, CA and works in Orland, CA designing and building sometimes useful things. You should follow him on Twitter or visit Circuit Case Engineering.