Drilling large hole in thin plastic enclosure

[coppercone2]

This is true, if you take the little cup you put laundry detergent in, fill it with water to make a soap solution, and dip fostner bits in it before you drill wood, it drills much much better

Dip before each hole, this is how I made my wooden trays for coaxial connectors of various kinds with more speed, less heat and no smoke

But you do need to wash it off and oil it when you are done. It might be the same for plastic and I bet it even might work on metal instead of oil. The main problem is that its too runny for metal. I wonder if you put some thickener in there if it would beat out oil, because its thermal conductivity and capactiy is much greater, and it might be just as slick

[5U4GB]

They are available in inch and metric (usually 2 mm steps).

You can also find them in odd step sizes if you need that although they're a lot less common than the usual 4, 6, 8, 10... steppings.

[themadhippy]

You can also find them in odd step sizes if you need that

or get a conecutter, although you need to pay attention with them.

[Jeroen3]

A small 4mm drill guide on the inside for the pilot hole.
Then with the step drill (that starts at 4mm) drill the remaining.

 

[Poroit]

It looks very professional....nice job

[Doctorandus_P]

If you have a drill press, you can make a punch yourself.

1. take a piece of square or rectangular tubing.
2. Drill a 12 mm hole in it.
3. Take the 12mm drill, and grind it a bit "hollow" on the solid end.
4. Put the drill upside down in the drill press.
4a. Likely, the chuck does not hold the drill straight, so position the square tube so it's hole is below the end of the drill.
5. Put your plastic in between the square tube and the drill, and push the back of the drill though it (no rotation!)

I sometimes use this method, but it does not work in all materials. It does not work well in brittle plastic for example.

[EC8010]

Chassis punch is the way to go. Greenlee in the US, Q-Max in the UK. Yes, step drills can be surprisingly good, but plastic has a nasty habit of behaving oddly when heated by the friction of a drill.

[themadhippy]

Chassis punch is the way to go. Greenlee in the US, Q-Max in the UK. Yes, step drills can be surprisingly good, but plastic has a nasty habit of behaving oddly when heated by the friction of a drill.

Its horses for courses ,  some plastics shatters  into 1000 bits or splits  when you try and use a q punch