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View Full Version : Router bits made especially for acrylic?



Mike vonBuelow
11-08-2011, 5:10 PM
I was thinking about trying some different router bits for my jade edge acrylic - to get something other than a flat edge

Does anyone know if this requires a special bit?

I really like the look of this edge

212385

Michael Hunter
11-08-2011, 6:12 PM
Extract from the Perspex Workshop Handbook -

"To achieve a good finish on Perspex from Lucite, all cutting tools must be kept sharp.
Most hand tools designed for use with wood and soft metals are suitable for use with
Perspex except laminate cutters, guillotines and blanking dies. If necessary, these
tools can be used with Perspex provided the sheet is heated to at least 50C. Most
power tools can be used and HSS tools bits are suitable to achieve a good cut finish.
For lengthy runs, tungsten carbide tipped blades and tool bits are recommended for
long life. For accurate work, especially where a high degree of finish is required,
diamond-tipped tools are particularly suitable for machining Perspex."

I have also read somewhere that cutting tools should be kept exclusively for acrylic - not to use tools that have been previously on wood or metal.

I see no reason why a new router bit (used carefully) should not work. Very fine cuts and moving quickly so the acrylic does not overheat.

Paul Phillips
11-08-2011, 8:55 PM
Mike,
I believe what you have there is called 3030 green edged acrylic, it's used to mimic glass. I'm sure you'll get varying opinions how to do this but I cut acrylic all day long on the CNC so I'll give you my 2 cents. I use the Onsrud 63-700 series End Mills. I know there are plenty of other brands out there but this is what I like the best based on price and performance, lots of good reading on their website about "how to" cut many different substrates. Follow their speed and feed rate suggestions as a starting point and adjust accordingly to your machine. In order to get a perfect polish on acrylic I take the piece from the CNC and sand the edges with a Dual Action sander down to about 400-600 grit and then use a plastic polishing compound on the buffing wheel, may take some practice but once done correctly it should look as clear as the face. The laser does an adequate job in most cases but usually leaves some striations on the edge so some people use a flame polisher to get a better quality polish. I haven't seen the finished product on the flame polisher compared to the hand buffed method so I can't say if it's as good a quality as hand buffing but I'm sure it's close. Do a search on here for polishing and I'm sure you'll find plenty of info.
Hope this helps.

Paul Grothouse
11-08-2011, 11:51 PM
Try Vortex Tool or Onsurd, they have bits designed for acrylic.

Rodne Gold
11-09-2011, 1:09 AM
If you use slightly soapy water as a coolant and lubricant , you get excellent edges and can increase cut speed and depth. The biggest issue with acrylic is cutter clogging , so you need to use one with lots of back clearance to remove swarf effectively. End mills will work , but if you really want to cut well , use a dedicated plastic type cutter , most tool and supply places have em. Make sure its one that does not pull the material upwards.

Doug Griffith
11-09-2011, 10:06 AM
For cutting, I also recommend Onsrud 63-700 series router bits. Downward spiral works especially well if a fixture is used to release the swarf. The part doesn't want to lift and there is less chatter.

The profile you refer to is most likely cut first then chamfered on a router table (using a 45 degree bit) as a secondary operation.