i have just started building a gantry mill for milling aluminum. travels will be about 50 inches x 62 inches x 12 inches. i contacted Hiwin tech support for help with sizing of the ball screws and guide ways. they need from me the thrust load on the spindle. does anyone know how to calculate this? largest end mill will be .750 diameter running up to 5000 rpm with feed rate around 80 inches per minute for roughing and 160 on finish cuts.
thanks for any help
keith
