the skimming thing is this piece here:



In the upper area, that surface skims along the main body part up here:



And it also skims along the very same shape along that needle area - for things like this it's usually better if a cutting surface more sharply cuts through the other surface. 2 surfaces that follow along a largely similar shape across a large region will tend to produce complex intersections, a more sharply pushing through one would be shaped more like this maybe:



- Michael