Another installment of "Loothing on a shoestring" ...
When re-gluing a neck after a neck reset I use the E strings to check alignment. The pull of the strings needs to be offset by clamping the neck heel to the body. For the last 20 years I've used a simple leather lined wood caul with a bar clamp. It works but requires flipping the guitar up side down to apply the clamp, flipping it back upright, and hoping that the clamp is tight enough to not slip off in the process. That adds time and stress you don't want when using hot hide glue.
Beau Hannam posted a video of a neck clamping system here: instagram.com modeled from a TJ Thompson design. If you decide to build a jig like Beau Hannam's, you can get the neck heel caul from TJ Thompson here: proluthiertools.com
I created a similar design using a Harbor Freight 24" bar clamp and 3D printed parts. Note that I'm using the current 24" bar clamp sold by Harbor Freight. You can identify the older Harbor Freight model by the wood handle and chrome finish bar. The older model has numerous dimensions that differ from the current model so it won't work with the printed parts. If you are really ambitious, there are parameters in the source file that would help you get started in modifying the parts to fit a different bar clamp.
The Neck Heel Inserts in this project is modeled after dimensions of a Martin D-18/28 and Gibson LG-0. I've included the Fusion 360 source files in the download so you can modify the Neck Heel Inserts to fit different neck heel profiles. There are parameters associated with the heel profiles to set basic dimensions. The heel shapes are created with a mirrored control point spline.
To create a neck heel profile, modify the parameters heelbottomwidth, heelbottomdepth, heeltopwidth, heeltopdepth, and then move the spline control points to dial in the heel shape. The top and bottom profiles should be oversize to account for lining the Neck Heel Insert with leather or cork. I'd be happy to add your neck heel profiles to the download file if you want to share them.
I printed with PLA, 20% infill, and support enabled. I included screenshots of print orientations that worked well for me.
The optional part named "Head Collar" can be used to keep the ball joint in the bar clamp head from wobbling around.
parts: 24" bar clamp harborfreight.com
3/32" cork sheet amazon.com
clamp feet lock screws 2 - 8-32 x 3/4" or M4 x 16
