Posted this in Andy's thread( http://www.bareefers.org/home/node/8090 ), but figured to start a new one since the topic comes up periodically.
Go ahead and post questions and or tips about working with acrylic here.
Go ahead and post questions and or tips about working with acrylic here.
Mr. Ugly said:Re drilling acrylic and similar materials... even brass...
You need to have a lot less rake on the cutting edge so you get more of a scraping action than shearing. With too much rake the acrylic can crack or shatter when the bit starts to break through to the other side.
You can buy special bits, but it's really easy to modify a standard bit with a whet stone or a diamond stone. Even a diamond wheel from your Dremel will work.
Just flatten the cutting edges of the 2 flutes on your drill bit. You can go for zero rake by honing parallel to the drill bit axis. A few degrees of rake is fine too, and that's usually what I go for.
Here's a pic to give you an idea.