Eclipse Style Chisel and Plane Iron Sharpening and Honing Guide

This guide is used to get the right chisel and plane projection lengths when using an eclipse style sharpening system. Its pretty similar to the original that it's remixed from except I added a lip to use it on the edge of the bench and I adjusted the projection lengths.

I noticed that the projections lengths printed on the side of the eclipse holder were not correct at all and decided to do some math for myself to make sure the angles were correct. I took some measurements from my eclipse holder and made a little spreadsheet to calculate the projection lengths for both plane irons and chisels. I made some assumptions in the calculations so it's not going to be 9th decimal place precise, but it should be good enough for woodworking. Also, I measured the thickness of my plane irons at 2mm. If your plane irons are thicker or thinner, it will throw the angles off (chisel thickness doesn't affect calcs).

Here is a link to the spreadsheet if you want to change things based on your plane/holder geometry. 

https://docs.google.com/spreadsheets/d/1cKMDMvD6pjQFPbNfR1wGktn8Qu3JUryL5vjNMZW3rUw/edit?usp=sharing