BB1, I believe the "traditional cross" uses the golden rule (Fibonacci Rule). DP (David Polaschek) did a post on LJ about a Fibonacci Guage he made. Unfortunately, I have enough trouble finding my own projects on LJ nowadays, let alone someone else's. Fortunately I plagiarised his idea and created one myself which I cut out on my laser (so physical dimensions aren't readily available from my records). They are relatively easily made once you have dimensions which are readily available from the internet... if push comes to shove I can make a PDF available that can be used as a template (resized proportionately will give you whatever size you like). Exact tolerances should not be critical as it is designed to give you the general layout and not necessarily in micro measurements (so I believe).
If your first cut is too short... Take the second cut from the longer end... LBD
