precise cut out for panel mount switch

[LaserTazerPhaser]

Is there a precise and inexpensive method to make proper cutout holes for panel mount switches?

This https://www.homedepot.com/p/100019434 and a dremel currently seems the only method.

[Dabbot]

https://www.homedepot.com/p/KNIPEX-11-in-Sheet-Metal-Nibblers-with-Comfort-Grip-Handles-90-55-280/300831359

[ChunkyPastaSauce]

https://www.popularmechanics.com/home/how-to-plans/how-to/a5940/how-to-work-with-sheet-metal/

[Ian.M]

I would scarcely call a Dremel precise.

The traditional method with limited workshop tooling and budget, is to mark up the panel, rough cut non-circular holes by a combination of drilling and fretsaw work, then file to exact dimensions.  Smaller circular holes should be center punched on the mark then drilled on a drill press with the panel well supported (e.g, by clamping or screwing it to a sacrificial softwood block).  A tapered reamer is helpful for non-standard diameters.  Large circular holes can also be done on the drill press with a fly cutter, or roughed out with a fret saw then filed to the marked outline.  Extreme care must be taken to protect the face of the panel against scuffs, dings and scratches if it is going to be visible.

CAD makes it easier to mark up the panel accurately - one can either do toner transfer, or simply print out a mask for all the non-circular holes, carefully cut them out with an Xacto knife, tape it to the panel as a stencil and mist with spray paint.   If using any sort of printout, make sure its correctly calibrated to correct scale distortions.

A nibbler can be useful, but don't push the limits of the material type and thickness its rated for and make sure its blade is easily replaceable and readily available, as sooner or later you are almost certain to snap it.

[Psi]

Yes, if its alu or thin steal then a nibbler is awesome.
Otherwise a dremel and a file is usually the easiest option.  Dremel cut-off wheels can be good to cut straight lines but make sure you wear eye protection, the non-reinforced disks will explode if you look at them wrong. The reinforced wheels are much better but always wear eye protection when using a cut-off wheel. Even the little dremel ones.

[mikerj]

The "precise" method is to use the appropriate punch and die set, but certainly not inexpensive.  Chain drilling and filing to size is my preferred method.

[Gregg]

One of my favorite methods is using the ends of old fine toothed hacksaw blades that are worn out in the middle.  I cut them in half, take off some of the back of the blade near the good end with a bench grinder to make it more maneuverable and use tape to make a handle.  These even can be thinned with a grinder but the tooth set is removed and makes the blade want to stick in the kerf.
For aluminum and most plastic; drill a suitable hole in the middle of the cutout; use the hacksaw blade to cut as close as possible to the corners and use a sharp chisel to score the cut lines using a block of wood to back up the chisel. Bend and break the remaining pieces out and finish with a file. 
Another method is to use a portable jig saw with the foot taped to avoid scratching and even tape the panel outside the cut lines.  A variable speed jigsaw with no orbital action and fine tooth blades can be used like a file to nibble away small amounts of material as well as cutting a straight line.
To keep aluminum from sticking to files and saw blades, I use stick wax made for metal cutting saws.