Tips on a really nice side milled finish in aluminum

[Kerry Harrison]

Greetings,

Anyone have any tips on how to achieve a nice smooth finish when side milling 6061 aluminum?

I have a Lagun vertical mill (BP clone) converted to CNC with ballscrews. I can't for the life me figure out how to get a really nice smooth finish when side milling. I have tried many different kinds of end mills and lots of speeds and feeds and I just can't seem to get a super smooth finish.

Any thoughts?

Thanks,
Kerry Harrison

[dertsap]

I lean toward hi helix for getting good finishes

[HimyKabibble]

Originally Posted by Kerry Harrison Greetings, Anyone have any tips on how to achieve a nice smooth finish when side milling 6061 aluminum? I have a Lagun vertical mill (BP clone) converted to CNC with ballscrews. I can't for the life me figure out how to get a really nice smooth finish when side milling. I have tried many different kinds of end mills and lots of speeds and feeds and I just can't seem to get a super smooth finish. Any thoughts? Thanks, Kerry Harrison

Try a 1/2" 2- or 4-flute HSS endmill, 3200 RPM, 12-15 IPM feedrate, with a 0.005"-0.010" radial depth of cut. If that doesn't give a nice finish, then either you're using crappy tools, or something is wrong with the machine (spindle runout, loose bearings, backlash, loose gibs, etc.). Use good quality endmills, not Chinese crap. The Putnam, Greenfield and Accurite from Enco and MSC are very good for the money.

Regards,
Ray L.

[HuFlungDung]

If you were to post a clear photo of the finish you can achieve at present, it might assist with diagnosis of the problem.

Cutter runout creates a scalloped appearance.
Conventional versus climb milling = poor versus good finish.
Wet cutting will produce a better finish. Continuous coolant during heavy cutting, or a spray film during light finish cutting helps.
Use a virgin tool that has not been used on other metals or for roughing. The tool should be sharp enough that it is dangerous to touch the cutting flutes. Uncoated is sharper because the coating tends to encapsulate the cutting edge which produces a radius over the cutting edge.

[tobyaxis]

3 Flute 40 to 45 Degree Helix ZrN Coated.

Harvey Tool Coating List Below. Comes in Handy

[LeeWay]

Check out the end of this video. I used a pretty plain 3/8" 4 flute end mill. Feeds, speeds and DOC are shown on the vid. It is showing brass, but did aluminum parts the same way with nice results.

YouTube- Milling Brass guitar part

YouTube- Milling Brass guitar part