This Jig was designed to minimize cleaning and reworking the binding and purling channel for instruments with an arched back, such as acoustic guitars. As you probably experienced, (or will experience) when you cut the binding and purfling channel with a router, the router base sits flat on the arched back surface and the cutting head is then tilted inward toward the instrument side. To adjust the channel you have to widen the channel where it tilts outward on the top edge.
This can lead to inconsistent results and variations in the finished thickness of the binding, which is a mark of an amateur builder. Some luthiers decide to address this problem by sanding the binding channel with files and sanding sticks, which can lead to inconsistencies and mistakes.
Another and much more expensive option are tools manufactured especially to address this problem. Some tools that come to mind are commercial routing devices which are fixed and offer a vertical travel, which keeps the router perfectly vertical. these devices can cost several hundred dollars and are more suited to large shops.
The Arch Binding Cutter Jig solves this problem more easily, by adjusting the cutter head on the router to a 90 (+/-) degree angle to the side by compensating the base of the jig to the arch of the instrument. The jig base is designed for both a 12' and a 15' radius base, which matches what you will need for our acoustic guitars. You can of course make additional bases to accommodate whatever radius arch you have on your instruments. While not perfectly vertical you reduce your work load by at least 90%
Finally touch-up channels with sanding blocks, leveling out all inconsistencies.
Note: As ALL of our plans are sold as digital downloads, when you complete your plan purchase with us, you will automatically be given a download link to access the plans.
We use the Bosch PR20EVS Palm Router for the binding work here in the shop. This router fits into your hand comfortably and yet has a 1.0 hp motor which can easily cut through the hardest wood with ease. Coupled with that we use a dual carbide tipped rabbeting router bit with guide bearings to give various binding and purfling channel widths. If your setup varies from these specs, adjust the dimensions of the drawings accordingly. The jig is designed to replace the plastic sub base on the router and is mounted directly to the metal base of the router.
If you desire, add a plastic knob at each end of the base. This will give you much more control and stability while routing the edge, minimizing slippage, especially around the waist and upper bout areas.
Plans show the assembled jig, along with complete dimensions and notes. Every part of the jig is carefully dimensioned and noted for clarity and ease of construction.
All our digital download plans are dimensioned in both inches/fractional inches and millimeters. The dimension are shown over/under the dimension line and will allow you to work in whichever measurements system you prefer.
All of these plans are electronic downloads. This plan is sized to print out on one 11"x17" sheet or you can splice (2) letter sized sheets together. The plans are at a 100% scale and you can use them as a template as required.