Richon Tools order

There i another aspect to factor in, and that is chipload per tooth (or edge) At 1920 rpm, with 4 flutes, you are presenting 7680 "cuts" per minute. How fast are you planning on feeding the mill? Aluminum, in it's vanilla form like 6061, anything between 0.005 and 0.015 per tooth/flute should be fine, if you have the HP and rigidity. That makes some fast feeding. ~38 IPM

And depending on depth of cut, you may find a blast of air to just keep the chips clear will be enough. Or a climb cut of 0.005 depth will leave a good finish. Lots of variables.
 
I in fact, tried cutting the aluminum plate with the new 5/8" end mill. I was blown away by the finish at 1900 rpm. I still think it's too fast. But can't argue with sucess.
I squared up the upright and base for the Elmer's #25 I'm building.

Going back to the formula DavoJ posted, what is the constant 4 for?

Anyone interested in the Excel Calculator I put together with DavoJ's info? Hardest part was getting the Excel function vlookup to work. That takes the metal material name I put in and looks up the SFM value per DavoJ's list. I then plug that and the cutter Dia. into a formula and calculate the RPM.

Actually, I would like folks to evaluate it and see if I need to add features for other 'noobs' like me. Contact me via PM or off list @ chunk07atcomcastdotnet, and I'll send you a copy.

Chuck in E. TN
 
Chuck, just for the record, the constant 4 is derived (according to an old high school shop text) from cutting speed, in feet per minute times 12 (inches per foot) divided by pi (3.14159) times diameter of cutter (in inches). 12/3.14159 is rounded off to 12/3 = 4. So, rpm = CSx4 / D. Close enough if you're changing speeds by shifting belts.
 
You must log in or register to reply here.
Back
Top