Hi Dan - A couple of things a) a 1/8" bit is way too small and not stiff enough for what you are trying to do b) get a 1 flute 1/4" bit and life will be easier. A 3T bit has a very small gullet so has no room to evacuate chips. A 1F tool has a big gullet so has a better chance to fling the chip. Tools need to be sharp and clean for aluminium. Al loves to stick to a tool surface. Once it builds up a little its history as its attracts more material, looses its edge and gums up. Now to the cutting spec. The thing to check is the mm/tooth or chip loading as sometimes called. This is the thickness of the chip the tool takes every bite. This can be calculated using chip load (or thickness) = Feed/RPM/no of teeth. So in the 18000rpm/14ipm/3T case (I work in metric) its 18000/355mm/min/3T. So this is 0.006mm/tooth. This is very very thin and the tool is rubbing vs cutting. Look at the 10000/45ipm/3T case ie 10000/1143mm/min/3T is 0.038mm say 0.040mm or 0.0016". I usually start at 0.05mm but 0.04mm is good. But a 3T means its filling up the gullet. Try a 1T at 0.05mm so at 12000rpm/600mm/min/1T = 0.05mm. Surface speed could be a little high here but a sharp tool with good lubricant will work here. Peter
look up chip thickness once understood and you have a a figure that works for your machine stick to it! For timber try to make it bigger until it jams then back down. This will give you large clean chips that don't get recut and no rubbing. This will max your tool life. Peter