One of the issues that ofttimes has to be dealt with is carving chip out - especially when V-carving small letters. In fulfilling an order for some plaques that had a lot of text in a small space I was disappointed with the readability. The text was about .3" high being carved with a 60 degree bit in black walnut. As shown in the first pix, readability was poor as the letters were "fat" and the walls separating the letters and islands within letters such as an "a" were being lost to chip out. Using larger letters or a different font were out of the question as the customer was very specific about what they wanted. Besides the toolpath review showed a nice result as it has no way of knowing how to deal with the characteristics of specific materials.
- Small letters cut with 60 deg bit
Sometimes these issues can be dealt with by kerning and node-editing problem areas but in this case that would have taken a lot of time.
SOLUTION: Create the toolpath with 60 degree V-Bit but put a 30 degree V-Bit in the CNC. This made for much more readable small letters (see 2nd pix).
- Small letters cut with 30 deg bit
Why it works: By fooling the cutting process the heights of the letter stays fairly good but the "fatness" is reduced leaving more material between and within the letters. Just creating a toolpath with a 30 degree bit and then cutting with it are not the same as then the bit will still carve out "fat" lettering. The process above mathematically shrinks the width of the cut - leaving more material. This trick also works when V-carving traced bitmaps which because of shading have a lot of closely spaced vectors generated!
The proportion of reduction of vector "fatness" can be controlled by specifying different combinations of V-Bit degrees and using smaller actual bits such as creating a toolpath spec'd with 120 degree bit and cutting with a 15 degree bit. This procedure will affect the shape of the corners so be aware of that drawback.