I am a novice and trying to get a good finish on 6061 aluminum flat surfaces. Not going well. The end mill 3/8" 4 flute leaves a slight pattern of semi circles if I use the end of end mill. I am using a spindle speed of 1200 rpm. I can't quantify the feed rate, but it is slow, and the depth of cut may be just a few thousandths. I would like a smooth finish devoid of tool marks. Maybe I am asking too much. The semi-circles are not enough to catch a fingernail on, but are plainly visible.
Side cutting with the end mill on an edge of aluminum bar stock leaves a series of vertical ripples no matter what I do with speed, depth of cut, or feed rate. ???
I then tried a fly cutter, but this was disastrous. Not really knowing how best to use these, I used one that had would best fit the piece of aluminum I had, even though the cutter was coming off the edge every revolution. To minimize impact, the cut was very shallow. But the finish was awful. A kind of smeared mess. I am sure my cutting tool is all wrong, but just can't get my head around how the cutting tool bit should be ground. I feel like I am grinding and grinding until I have no tool left. Clearly, I need a better understanding, like holding one in my hand.
Any advice would be helpful. I am using a Rotex vertical/horizontal (2 motors) knee mill with a 5" x 20" table.
Thank you.
Phil
Side cutting with the end mill on an edge of aluminum bar stock leaves a series of vertical ripples no matter what I do with speed, depth of cut, or feed rate. ???
I then tried a fly cutter, but this was disastrous. Not really knowing how best to use these, I used one that had would best fit the piece of aluminum I had, even though the cutter was coming off the edge every revolution. To minimize impact, the cut was very shallow. But the finish was awful. A kind of smeared mess. I am sure my cutting tool is all wrong, but just can't get my head around how the cutting tool bit should be ground. I feel like I am grinding and grinding until I have no tool left. Clearly, I need a better understanding, like holding one in my hand.
Any advice would be helpful. I am using a Rotex vertical/horizontal (2 motors) knee mill with a 5" x 20" table.
Thank you.
Phil