Baby Bass Neck

Here's an example of a custom neck that I did recently. A customer here in the LA area brought an Ampeg Baby Bass to my friend, luthier Mike Lipe. It was about '64 vintage, and unfortunately, the neck had badly warped, bowing forward. Mike brought it to my shop, and we looked it over to see what could be done. Besides the warpage, the fingerboard was badly cracked, so it didn't seem worth it to plane it down to correct the bow. The customer decided to go for a complete new neck, built from scratch, with extra reinforcements in the neck to keep it stable.

Mike and I did this project together. I machined out the maple blank, rough shaped it, blanked and planed the ebony fingerboard, and built the truss rod system. Mike did all the final shaping and smoothing, installation of the hardware, and assembled and set up the instrument. It came out very well, and the customer is thrilled with it. My truss rod system under the overhanging fingerboard was kind of an overkill, but it apparently added some extra brightness and sustain to the instrument.

This was a complex project, and Mike and I both put a lot of hours into it. A custom neck like this costs about $500-$600. In this case, the slab of ebony for the fingerboard alone cost me $75!

Here's the block of maple that the new neck was made from. Because this was a one-off, I did all the layouts right on the block. I machined the slots in the headstock, the tuner holes, the slot for the carbon fiber reinforcements, and the counterbores for the scroll pieces on my milling machine.

The completed neck, in the foreground, next to the original neck.

On this project, I shaped the fingerboard completely before gluing it to the neck. The profile is the classic upright style, which is an increasing radius with a flat under the E string. Because this was a one-off, it wasn't worth it to make up a special fixture to cut the profile with a router. So, I cut it the old-fashioned way, sticking it to a long board and hand planing it to shape with a very sharp old Sargent jointer plane.

Here's the neck (on the left) with most of the rough shaping done. A bundle of carbon fiber strands was embedded in the neck down near the bottom to keep it from stretching and bowing over time. You can see the counterbores on the sides of the headstock that the cast resin scroll pieces will fit into. The neck blank on the right was also for Mike, for a custom order electric bass for another customer.

This is the monster truss rod system that I made up to allow adjustment of the overhanging end of the fingerboard. I machined up all the parts from brass and steel, and used a milling machine to cut the recesses in the underside of the fingerboard. That truss rod is 1/4" drill rod, with 1/4-20 threads. It takes a lot of muscle to bend a 7/8" thick slab of ebony! It's double acting, to allow the fingerboard to be adjusted up or down.