I have tried a slower feed rate but it blunt the end mill to a point it was not cutting but I cant remember the setting since then I have started to keep a note of what I have been trying. If I took the spindle speed down to 10000 rpm then the feed rate would be 30inch a minute or 762mm per minute, at a chip load of 0.003 but if my feed rate is to fast at 15000 rpm at 1142mm per minute should it not be the case that at 10000 rpm at a feed rate of 762mm per minute still be wrong. is there something wrong with the calculation that I have found or is it the chip load that is wrong for a 1/8th single flute end mill. also how slow can you take a water cooled 0.8kw spindle before it would stall when cutting.