I’m going to “cut” right to the chase and tell you what the best 2 ways are to cut square or rectangular holes in a plastic project box or enclosure. But regardless if you agree or not or whatever method(s) you do use, I’m also going share a little secret to make any square or rectangular hole look professional with very little work, even if you aren’t good at cutting nice, tidy angular holes (most people aren’t). So let’s get to it…
Method 1: Manual 40+ TPI saw blade
This is my favorite way. It doesn’t melt the plastic when done manually and you have a lot of control. As long as you take your time, you can get very nice lines that require little or no file touch-ups. You don;t have to go out and buy some fancy saw, you can just buy a 40 TPI (or higher) jigsaw blade, wrap the top 1/3rd of the blade (the part that would normally attach to the jigsaw) with a nice wad of duct tape to make a handle and wear a glove.
Of course, when using a saw blade, you have to drill at least one pilot hole at one of the inside corners of your hole. In fact, I find it best to make 4 holes, one at each corner. Then, just say inside your like from one whole to the next.
Method 2: Manual Nibbler hand tool
A Nibbler is another great way to make a nice and neat square or rectangular hole in plastic project boxes (or even thin unhardened metals). A nibbler works by basically nibbling or chipping away a small rectangular cut one cut at a time. it does take a little practice to get a perfect line, but a nibbler can definitely achieve it.
You start by drilling a pilot hole (usually about 3/8″) anywhere within the lines of where your hole should be, then you insert the nibbler bit and nibble away, one nibble at a time. It does have a little bit of a learning curve, but not much. A nibbler is a great tool to have around for a lot of small projects.
And now the part you’ve been waiting for…
SECRET: How To Get a Tidy & Professional Look Even if Your Cutting Skills SUCK!
Yeah, yeah, I know, DigiKey and Mouser and every other parts supplier only carry a few bezel sizes and they’re never the size you need.
But there’s a solution…
…a cut-to-fit bezel from DIYBezels!
It’s so easy because all you have to do is cut the rails to the size you need (I recommend using a 40+ TPI saw blade as mentioned above). Once you do that, you just attach the corners and – VOILA! – you have a custom-fit bezel. Just glue it around you hole and now your hole has a nice, finished look. I highly recommend these bezels for any square or rectangular hole, even if you have great cutting skills. No bare hole looks as good as hole with a bezel, IMHO, because it’s just a bare cut. Even if you have your hole perfectly cut using a laser or CNC, it’s still a bare cut.
But what’s great about using a CTF Bezel from DIYBelzels is you don’t have to waste time getting a perfectly cut hole. You do have to get it somewhat straight and clean, but not perfect because you’re using a bezel to cover your work. Using a bezel saves time in that respect and, IMHO, always looks better than a bare cut.
Update: Sorry, DIY Bezels seems to be out of business now…sigh.