I use these Pinfox boxes for a variety of things (including filter and meter housings) where I need to install a
power-pole connector on each end of the box. Cutting square/rectangular holes is always a hassle, and after much
hunting I've determined that a rectangular punch for a power-pole is impractical for me to use. I found the die,
it's a 8.5mm x 16.5mm, but requires a CH60 press, which is powered by a user-provided hydraulic source, which I
don't have and can't justify getting for this one use. The 9/32" hand punch makes holes 7.2mm in diameter, which
is slightly smaller than the 7.5mm target width, so I don't have to be super precise with the hole placement.
So the new plan is to use an old hole-punch to make round holes in the box, to get the plastic-carving process
started. I begin this process by using masking tape to mark off the 8.5x16.5mm hole, and then punch a pair of
holes. Then I cut out the middle with a side-cutters. Finally, I use an X-acto knife to carve out the remaining
area and clean up the hole.
To keep things as safe as possible, I use the knife with very controlled, slow plunging motions, to carve off
curls of plastic a bit at a time. It's tiring on the hands, but gets the job done and produces pretty good
looking results.
When carving, make frequent fit-checks with a power-pole connector, to avoid removing too much material and
getting a loose fit. Also make sure the angle of the power-pole is correct, not angling down or to the side.
Leave several millimeters of space between the hole and the edge of the plastic, both for structural reasons
and to give yourself a place to lay down hot glue for anchoring the connector. If you glue the sides and the
outside edge well, you won't need to bother with gluing the inside edge, which is challenging to access.
Before applying the hot glue, attach a cable to the connector and lay it out with supports so it holds the
power-pole at the correct angle and depth while you apply and cool the glue. Make sure the glue is fully cooled
before pulling out the positioning cable.
