Use layout dye, mark and center punch, drill 4 corner holes, use a saber
saw with a metal cutting blade and SLOW speed, clean up with a big file.
Should take about 30 minutes. It helps to file some squaring notches in
the holes with a 3 corener file to get the blade started square. Ugly
but it has been done a million times.

Ignoramus27829 wrote:

I have this compressor

http://igor.chudov.com/projects/CurtisCompressor/

and this hourmeter

http://igor.chudov.com/tmp/hourmeter.jpg


I would like to make a rectangular opening in the mounting base for
the motor and pump, so that the hour meter would be facing the same
direction as the pressure gauge, and look nicely, like it was mounted
by the manufacturer. I would prefer that to making some stupid
little enclosure for this meter or mounting it in odd places.

For this, I would need to make about 3/4" by 1/5" (that's a guess)
opening in the mouting base, which looks to be like it is 3/16" mild
steel.

The question is, can this be done sensibly with, say, a jigsaw and
bimetal blades.

Another question is, can such a meter take some vibration. It is not
bad, as such, and I suppose that these Stewart-Warner hourmeters are
made to withstand some vibration.

i