[Leonelix]

I'm having surface finish problem cutting Intraocular lenses. I use a .230 mm 2 flute end-mill to profile the lens. The problem is that portion of the chip remains attached to the upper edge of the lens profile. This lenses are made out of a special type of acrylic, which is soft and gummy. My theory is that sometimes I get batches of material that are softer than others so that the end-mill does not shear at exit of the part, but rather pushes the material. I also noticed that the end-mill flutes are course (the cutting edge is sharp, though).

Any thought in this regard will be appreciated.

[underthetire]

Cutting any optics is a challenge. We can cut optics without the need for any second ops other than a final polish. Expensive equipment for sure!

Sharp sharp sharp tools. I'd look at getting micro polished end mills. A little more but well worth it for what your doing.

[fizzissist]

In addition to seriously sharp tools... perhaps even a fresh tool for that final pass... Climb cutting at the edge so the cutter is cutting into the body will help minimize a chip that shouldn't be there.

[BAMCNC.COM]

Are you starting on the edge, or ending there?

[Leonelix]

Are you starting on the edge, or ending there?

No, actually the tool plunges down and then profiles all around until it reaches the point where it plunged at the beginning. Much like a slot, one side in climbing and the other is conventional milling. The finish part is cut in climbing mode. Thanks.

[Leonelix]

Thanks everyone for your thoughts, your're been helpful.