images from a Heritage Tribute '55™ lefty build I'm wrapping-up for a client in Australia
I have utilized numerous different ways for securing pickups into their cavities over the years, and have always had reservations with one method or another until I started utilizing brass threaded inserts and stainless machine screws the middle of 2009. I like the ease and detail of adjustments that a fine thread machine screw offers that a coarse threaded wood screw simply cannot equal. I also like that, barring total abuse by an owner, there's very little potential for a screw head becoming stripped and inoperable even after repeated adjustments. and for those who like to swap pickups on a near weekly routine - I like that the mounting holes won't become worn out and unable to secure the pickup in place even with a firm piece of mounting foam underneath
so, just what do you need to do this yourself?
- a drill press (aka pillar drill) is a must for installing pilot holes that are dead-on perpendicular to the body top plane
- a quantity of 4-40 brass inserts designed for wood use
- for the specific inserts I use, an 11/64" drill bit is the size recommended by the insert manufacturer
- a short 4-40 screw with a pan head
- gap filling, slow set CA glue
NOTE: For those in the US, I've found these inserts and stainless pan head screws readily available at Ace Hardware
I start off the process by placing the pickup into the cavity, and then install the outer two strings so that I can be assured that the pickup pole pieces will be aligned with the strings. if any adjustments needs to be made to the neck install angle, bridge location, or pickup position - it should be done prior to proceeding.
I then use a transfer punch sized to match the clearance hole in the pickup shell to mark the center point of the mounting hole location. After marking all of the mounting locations and removing the pickup from the cavity, I then set the stopping depth on the drill press about .25" deeper than the insert is long and drill the pilot hole
To install the insert, screw the pan head screw into the insert making certain that the slotted end of the insert is opposite of the pan head of the screw and on the end that will make first contact with the body (opposite of where the pan head will rest) -
that slot is for aiding the insert to cut its threads into the wood and [COLOR="Red"]NOT[/COLOR] for utilizing a flat blade of a screwdriver to turn it! Add a drop of CA glue about 1/3 the way down into the hole making certain that you don't use so much that it will pool at the bottom of the hole and/or squeeze out at the top of the hole when the insert is installed. gently twist the insert into the hole until the pan head of the screw is flush with the bottom of the pickup cavity. You could also insert a flat washer onto the screw prior to twisting it into the insert, giving you a larger surface to turn against ... I haven't found this necessary for these small inserts
After giving the CA glue a few seconds to set, remove the screw from the insert and repeat the process for the other pickup mounting holes.
One critical point in this process is to be certain that your transfer punch is perpendicular to the body top plane when marking the mounting hole locations. If you have the punch at an angle, the location of the center mark will be off ... and your pilot hole will then be off ... and the pickup mounting hole may therefore not match to the location of the threaded mounting hole.
I also can't stress enough the requirement for utilizing a drill press / pillar drill to install the pilot holes. This is NOT a job for utilizing a hand drill IMO and IME
all the best,
R
