Putting the Breaks on Micro End Mill Breakage
Put the Brakes on Micro-Endmill Breakage
September 27, 2010
Bill Kennedy, Contributing Editor of Micro Manufactruring Magazine
As parts and part features shrink, so do the tools required to machine them. Process factors that are not critical when using macroscale tools literally become make-or-break considerations at the micro-scale. An inappropriate cutting parameter or toolpath can snap a tiny tool instantly.
That’s certainly the case with endmills, one of the most commonly applied micro-tools. Micro-endmills 0.005" in diameter and smaller operate under their own set of “unbreakable” rules.
Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass., said the most important factors in controlling micro-tool breakage are speeds and feeds. “If you don’t have the right rpm and feed rate and, therefore, the right chip load, you are going to pop that tool right off the bat.”
If the chip load is too small, the tool rubs instead of cuts, wears, heats up and breaks. With too large a chip load, the heavy cutting pressure will snap a microtool. The key is to find the combination of parameters where the tool remains intact and cuts effectively.
Read the entire article at micromanfacturing.com >>