Trochoidal Toolpath Tid-Bits

To All:

The October issue of MoldMaking Technology Online magazine had an article on trochoidal toolpathing. Let me copy some excerpts:

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Heat: By using trochoidal paths you can minimize heat build-up. Controlling heat is paramount in getting consistent performance from high quality tools in difficult alloys. Heat dramatically reduces tool life and is a major cause of tool failure. The reason trochoidal toolpaths reduce heat is the curved paths minimize the arc of engagement. By using a smaller cutter and arcing the tool in the cut, the amount of contact with material is minimized and the flute spends less time in the cut.

Speed: There are also other advantages to using trochoidal toolpaths. Because heat is minimized you can cut materials at much faster SFM. And with trochoidal paths you can take deeper depth-of-cuts in the Z-direction. Typically the Z depth-of-cut can be up to two times the diameter of the cutter.

Tool Selection: Smaller diameter tools are typically used, reducing the cost of the cutter and lowering the overall expense of manufacture.

Summary: By using newer programming techniques, difficult material can be cut easily. Use smaller diameter tools to minimize the arc of engagement and control heat. Many newer materials entering the market tend to be more exotic and difficult to cut. Use specific cutter geometry for each application. By using trochoidal toolpaths and hybrid trochoidal toolpaths you can successfully machine these exotic materials.

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Reply to
BottleBob
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Not a big fan of trochoidal toolpaths. I *am* in love with constant angle of engagement type milling though. Since I started using X4 in Feb, virtually every production part I've programmed has used the "Dynamic Milling" toolpath. (It's Mastercam's version of Surfcam's Truemill). I was right on the verge of buying Cimco's HSM performance pack, or the Volumill add-on, but dynamic milling in it's current state is good enough to get me by for the time being.

I used to always use a large tool like a two inch 4 insert face mill, or a 1 inch solid carbide endmill to rough pockets and contours. Since the introduction of dynamic milling option, I haven't used a 1 inch endmill on a single new program. It's just not necessary. I just use a half inch endmill to full depth, set the max width to .100, the back- feedrate at 1000ipm, and let the software do it's thing. It's absolutely outstanding.

Reply to
Joe788

Joe:

"Constant angle of engagement" and trochoidal's "Arc of engagement" seem to be using similar basic philosophies. Deep Z depths and taking little radial "bites", being careful to not bury the tool in corners.

I was always partial to either Iscar's or Mitsubishi's 3/4" inserted end mills.

1000 IPM on return paths, eh? I wouldn't want to see the carnage if it hit a boss or some material it didn't think was there.
Reply to
BottleBob

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