[sdiy] Making holes in plastic

[Steve Lenham]

You're thinking of Q-max punches. They are intended for sheet metal and are 
unlikely to be much good for plastic - because they push through the 
material gradually, unless your plastic is very soft it'll almost certainly 
crack before you get very far. (If you need them, though, they're in the 
Rapid catalogue).

A few alternatives spring to mind:

1. Use a flat wood-boring bit. They are available in large diameters and 
produce a very neat hole in plastic - I used them on some plastic electrical 
backboxes with good results. Downside is that they may not be precise enough 
for you positionally.

2. Use a step drill bit. These are always recommded here for getting neat 
large holes in metal panels, so should make short work of plastic. However, 
without a drill press, the position of the hole can wander quite a bit from 
your pilot hole (this happened to me just yesterday - I don't have a press 
either).

3. I just noticed a set of hollow punches underneath the Q-max punches in 
the Rapid catalogue. It says that they are "specifically designed to cut 
clean holes in leather, paper, plastic, wood, etc.". You just brace the 
panel against something, put them in place and whack'em with a hammer. The 
largest one in the set is 0.5"/12.7mm. Looks like quite a good solution 
(though I've not tried it).

Hope this helps,

Steve L.

----- Original Message ----- 
From: "Fiercefish" <fiercefish at btinternet.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, October 15, 2005 5:37 PM
Subject: [sdiy] Making holes in plastic


I have a project where I need to make some very neat holes in a plastic 
enclosure, drilling is not an option due to the size of the holes (about 
12mm/ half inch) and I don't have a drill press, also the placement of the 
holes needs to be very accurate. Which would be a good method?
I was thinking of those devices that go each side of the material and are 
pulled together by means of tightening a bolt, drawing the two parts 
together, but I can't remember what they are called nor where I have seen 
them. Any other suggestions or tips welcomed!

Thanks

FF