A Real Smooth Shave

A typical thicknesser blade chips away at the surface of the material and looking closer at what is happening it is like using a chisel straight onto the work, causing a shaving to be generated in front of the blade.

This certainly works well on normal, relatively straight grained timbers, and with a typical thicknesser, the number of micro-chips produces a smooth surface. However on tricky, gnarly grains, the action produces significant amounts of tearout.

Where a chipping action fails, a slicing action works like a dream. To get a tool such as a thicknesser or router bit to slice rather than chip, you need a spiral rather than a straight blade. However, getting a curved blade is not impossible, but would be rather expensive. To get around that, having lots of little blades mounted along a spiral path not only makes the concept feasible, but also means the blades can be tungsten carbide, rather than just high speed steel. Also, they can have up to 4 sides, so when one becomes dull, it can be rotated, rather than just replaced. This has obvious benefits if you try planing something with a hidden nail- only one small cutter needs replacing, not an entire blade (set).

The deluxe Carbatec 15″ thicknesser has just had a makeover, and can now be purchased with a factory-fitted spiral blade. Existing owners are likely to be able to purchase the spiral head to upgrade their machine if they want.

Tempting eh!

Addendum:  I’ve been looking at these images (taken on the iPhone, and posted from there as well), and now looking closer, I am a bit confused why the individual small blades are all orientated as they are – I would have thought they would have been angled to follow the direction of the spiral.  As they are, their only advantage will be that they produce a smaller chip, not a slicing action-the real benefit of a spiral cutter.

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