Hello everyone I'm a first time poster. We are cutting some .017" & .025" wide slots by approx. .050" deep. We are going to use 2 flute centercutting carbide endmills. The material is 6061 aluminum. The max rpm is 10000. Would anyone have some starting points for these? Thanks.

Larry

Have you looked into using a slitting saw?

If you are doing a lot of these it could be worth the cost of getting a right angle head so you can use this.

A 0.017" wide slot 0.05" deep in 6061 is going to be a challenge and the cutting time much, much longer than with a slitting saw.

I would not even try with an endmill.

Geof, it's not a thru slot. There is two different parts with approx. 50 slots each about a 1/4'' long. They are to locate parts by their flange to be laser engraved.

I am currently running parts with a .027" centercutting carbide endmill. RPM is 7500, plunge speed 1ipm, feed 3ipm. I take .010" on each pass. Not quick but no broken bits yet.

.027 is larger than .025 and much larger than .017. How deep are you going with .027?

A slitting saw does not require a throuh slot; plunge it in like you would with a Woodruff cutter. If it is necessary to have an end to the slot to locate parts simply put another slot at 90 degrees and insert a piece of shim as a stop.

The endmill is going through a total of .030". First cut is at Z-.235" and last cut at Z-.265". Makes three passes removing .010" each time. More specifically, I'm doing these (http://www.mc-machine.com/87dash/clear6.jpg). I have used .0156" endmills before as well. Patience is the key obviously. :D

Use as much rpm as you can get away with, and as big a dia. cutter as you have room for. Your depth cuts will not be more than .002-.005. Set a feedrate to get about .0001/.0002 chip load. 4ipm at 10k rpm is .0002 chip load. Do not plunge into your cuts. Either pre-drill to within .001 of bottom of slot or ramp into the cut at about 2-3 degrees. Harvey Tool makes really great miniature endmils. Use as short a cutter as you can, and lots of coolant to flush out the chips. Good luck