I made a mess and broke a tool - mill side cutting an arc - T6061

[dansawyer]

The mill is a BOSS 5 running Linuxcnc. The project is to cut a shallow arc in t6061 - 2 inches long and the total arc depth about .150 in maximum depth.
Questions 1: The cut depth on each pass is .1 inches, the rpm 1000, the tool 1/4 inch end mill, and the feed rate 15 ips.
The arc was cut using conventional or 'up milling' The result was the the mill clogged and the milling process moved the part.
Should I try climb milling?
Question 2: The blank is 12 inches long, 1 1/2 wide, and 1/2 deep. I clamped it with 3 clamps, one at 3 inches from the cut, one at 6,and one at 12. The cutting was between 0 and 2 inches. I had the clamps were very tight yet the part moved.
Do I need to make a jig using the bed slots?
Thank you, Dan

 

[markba633csi]

Feed rate could be too high- are you using cutting fluid? Aluminum likes to weld on to the cutter when dry which increases the cutting force.
Pictures would help to diagnose
-Mark

 

[BladesIIB]

Sounds like you had serious chip weld. 1000 RPM seems very slow in 6061. HSS could run up to 7500 and a carbide bit over 10000 RPM. That low speed and high feed could have led to the chip weld. Try more speed and if you don’t have flood coolant try some WD-40. Great live for Aluminum cutting.

 

[JimDawson]

I agree with the comments above. Feed rate is much too high for the RPM you are using, the numbers you are using would give you 0.0075 chip load, a bit high for a 1/4'' end mill. 3500 RPM, with coolant would be more in the reasonable range.

At a minimum keeping the tool wet with WD40 would help, best is a spray mist coolant to blow the chips out of the cutting area so you are not recutting them.

Climb cutting is prefered on a CNC machine.