Why aren’t the exact locations of the tuning pins and bridge pins called out on your harp blueprints?
That is a great question. We have always wanted to find a way of pin-pointing the exact placement of tuning pins and bridge pins along the harmonic curve. We can easily measure and double-check our figures along a straight line (as for the soundboard), but it is very difficult to do this along a curve. How do we even describe the curve when it is an arc without a consistent radius? The challenge is even more difficult because the spaces between the strings are wider in the bottom octave than at the top, due to the varying thicknesses of the strings themselves.
This is why we have not attempted to call out the spaces between tuning pins and bridge pins on a harp neck, and it is why we provide full-size drawings that can be used as templates. Granted, there can be some distortion from the optics of the printer and from swelling/shrinking of the paper, but the results of trusting the image on the blueprint have been very successful over the years. We’ve not heard one complaint from a scratch-builder about unacceptable string spacing because of trusting the plan.
If you don’t have the full-size print, we recommend taking the digital file to Kinko’s or some other place that can print on big sheets. You have our permission to make one “working copy” from that copyrighted plan.