Glad you are still around. I felt pretty embarrassed when I noticed that I responded to thread was several years cold.
The side forces are not really that easy to calculate. It depends. Geometry of cutter, size of cutter, speed of spindle, depth of cut, feed rate of the spindle, sharpness of cutter, amount of lubrication, grade of AL. Most times it is the skill of the operator to adjust on the fly. Computers still can't adjust to circumstances as well as a human operator.
Originally Posted by
rutman
Ok thanks for the feedback.
Since writing that back in '09 I've gotten ahold of some excellent linear bearings off a CT scanner that made its way through the junkyard I've been fooling in.
2 each of 166cm, 74cm, and 4 of 50cm.
So I've designed something around those that is intended to mill aluminum and anything softer. Also for the eventuality that I can spare the money, I am leaving room for a laser head.
The mill axle is held within another concentric cylinder which travels in Z with the mill axle. This is to provide extra rigidity due to the large throw of the machine (50cm) meaning I have 0.5Nm of side-force induced torque on the mill head for every Newton of side force. I suppose I need to do the maths to see the deflection on a 50cm diameter rod under e.g. 250Nm of torque. Does anyone happen to know what side forces to expect on a mill cutting aluminum at some reasonable (nonindustrial) rate?
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