PATTERN ROUTING

Cutting non-wood with router bits requires some careful consideration to bit geometry, but straight cutter bits are probably the worst. Those spiral cutters, especially the fancy Whitesides with the up/down action are tempting, but definitely spendy.

I pattern cut some 1/4” 6061-T6 some years ago and after getting as close to the template as possible with the disc sander, I ended up using a 3/4” 4-flute spiral HS steel end mill with a 1/2” shaft (oddball bit, usually they have the same shaft diameter as cutter diameter). I use a router bit bearing on the shaft to make it into a pattern bit and everything went well.

Be aware that the larger diameter bits really like to grab and throw things when they catch, be sure you have a good grip!

Have you looked at machine mill ends? They are relatively inexpensive and probably better suited for cutting metal (the aluminum you are cutting). You would have to change your method of template guide by using a guide mounted on the base of the router and make an appropriate change in the size of your template.

-- Les B, Oregon