Mechanical question

[dhouston]

I've never seen one for plastic and the ones for metal are quite costly.

An alternative might be to have the company that supplies your plastic box machine the holes. Here in the USA, I've used Polycase, designing my board to fit one of their standard boxes and having them machine them.

[kellyseye]

Unless you plan to do 'lots' of hole punching, be prepared to bone up your cutting-and-filing skills as the proper tool for punching holes is VERY expensive. Consider printing a template onto adhesive plastic sheet, using a craft knife to cut the hole in the sheet and placing the sheet over the 'dodgy' hole you cut. You can make some fairly professional finishes using this technique.

[rsocor01]

I might be wrong, but I don't think you can "punch" holes in a plastic enclosure. Like Dave said you can pay somebody to make the holes for you or you can buy your own CNC machine. There are a few members of this forum that might be able to guide you in the right direction in case you decide to get your own CNC machine.

Robert

[keithdoxey]

I made a jig for cutting connector holes in plastic panels and boxes. Mine werent for DB9 connectors they were for SCART AV Connectors which are basically rectangular but with one end at an angle.

I made the jig from MDF and made it larger than the hole required then using a router with a follow collar just ran it round the inside of the template.

[dhouston]

or you can buy your own CNC machine.

Even a small, bench type milling machine with digital scales/readouts would be fine for low volume. There are some with retrofittable CNC controls as well as numerous DIY projects to add CNC to small milling machines and lathes.