To All:
Now here's a real End Mill Flute design I've never seen before - outside of some off-the-wall router bits. It's for cutting composites. A lot of times when cutting composites they tend to delaminate, what we did is sandwich them between a couple of layers of sacrificial material. Time consuming since the clamping would have to be moved from one side to the other. For drilling we made sure they were sitting on a scrap subplate for bottom support. Anyway here's a different solution from an article in Modern Machine Shop Online. Excerpts from the article follow:
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This cutter has both up-cut and down-cut spiral flutes that compress the layers of composite materials during milling operations, preventing delamination at the outermost layers and also between inner layers. Machinists, on the other hand, sometimes struggle to effectively mill and drill composites because the materials possess atypical properties that require special machining practices.
Onsrud Cutter, a member of the LMT Group, offers six-flute composites cutting tools with specific geometries and coatings to overcome these machining challenges. The company?s ?compression cutters? have intersecting up-cut and down-cut spiral flutes that push individual composite layers together during machining to prevent the layers from separating from each other. This action prevents delamination from occurring at the outermost material layers. It also averts delamination of inner layers, which can be a less noticeable workpiece imperfection.
The company currently offers these tools as customs, but a standard product line will be available in 2010. ==================================================================