Installing threaded inserts (insert nuts) on a neck (long)

[Pilgrim]

The bass is an Epi EB-0 with stripped screw holes in the neck.  I decided to install 10/32 threaded insert nuts from ACE Hardware to make it mount securely.  There was very little room between the screw holes and the sides of the neck, but I thought I could make it work.  Some of the ideas in this come from this thread at another forum: http://www.unofficialwarmoth.com/index.php?topic=5997.0

Here's the primary tool I used: a 1954 Shopsmith Mark V - which in its basic form is a table saw, disc sander, lathe and drill press. Some of you are familiar with it, others not. I needed the drill press function to drill holes for the insert nuts.  The Shopsmith is basically a motor on a chassis and rails; the motor has drive shafts extending out each end, and accessories either mount on the shaft with one set screw, or use a PTO arrangement.

As you see it here, there's a bandsaw mounted on the left side and the disc sander is visible on the right side of the motor...I removed them for the next step.


With unused accessories removed, there's a lever to flip on the left end of the chassis, allowing me to tilt the entire motor and mounting rails up to vertical, where they lock in place.  Here's the lever flipped up:


Here's the motor and rails in drill press position. The table which is the work surface for the table saw function swivels 90 degrees and becomes the working surface/support for the drill press. The 1/2" drive chuck for the drill press is sitting on the table - it connects to the power shaft with one set screw.


Here's the neck on the work table.  It's in a machinist's vise with padded jaws.  There's a level sitting on the neck mounting surface to help me assure that the neck is level up/down/left/right.  On the left side of the table you see a block of lumber and a wedge between it and the neck.  By sliding the wedge back and forth I was able to apply fine adjustments to leveling the neck down its length.


This hole is being drilled...

before drilling each hole, I re-positioned the neck and checked it for level in all directions.
Three out of four holes drilled....only the near hole on the left remaining.


Here's an insert sitting on a block of paraffin.  It's a good idea to lube any screw or insert before intstalling it in wood - I like to keep a block of good old paraffin, same as used for canning.  It was about 30 degrees in this shop even with a heater going, so the paraffin didn't stick to the insert very well.


These inserts used a hex key drive to install, so I chucked up a bit driver extension in the drill and inserted the appropriate bit.  I didn't use the motor on the Shopsmith to install this - it would have been uncontrollable.  I just grasped the chuck and turned it manually while using the drill press handle to apply slight downward pressure to force the nut to start.


Four inserts installed.  The bottom right one chipped the finish visibly, and created a slight crack on the edge of the neck.  However, given that this area is not visible when the bass is assembled, I can live with it.


The neck plate for the Epi required V-head screws, therefore I needed V-head bolts to mate with it.  ACE had chrome-plated 10/32 machine bolts with hex-head drives, and at $2.70 each they weren't cheap but they were perfect.  I used 1.5 inch bolts and the length was perfect.  This is a a serious consideration because you can't drill into the neck very far past the depth needed to install the insert nut, and you cannot have the bolt stick through the nut and into the wood beneath the fretboard.


The final product - looks factory clean, and that neck is held in place more firmly than any wood screws could secure it.

[OldManC]

Pretty slick. And I like that heavy duty everything and the kitchen sink Shopsmith you have there!

[SKATE RAT]

what's the rag top behind the Shop Smith?

[Pilgrim]

1958 Fiat Roadster:

[Dave W]

Nice work getting those 2 inserts at the end of the neck to go in without splitting.

[SKATE RAT]

ooooooooooooooooooh

[Denis]

Nice job! Both the ShopSmith and that Fiat are terrific!

[sniper]

SkuttleFunk used to be a regular poster back on the home planet forum before it exploded but after we boarded the space ship and hurled our bodies out into the void.* He is also an endorser of Dark Star pickups (which are not bad having taped one onto a bass at one time IMHO). The trick works for bridges also giving a bite more string vibrant "chime" to the body.

An old project with the same trick in the neck and bridge (a used BadAss). Sorry the pic is blurred but the bass is gone so no more pics. The pickup is an old StarFire/Hagstrom and not a Dark Star. The other mod was to put a 30 year NOS (read saved from an old warehouse full of Kalamazoo Gibby stuff!) Epi 34" neck onto a newer short scale Epi EBO. A black plate surrounded the bridge and covered the old bridge holes made out of material that matched the new pickguard. The neck plate used was from an old Grabber to match the original holes in the neck from the old Kalamazoo factory. The original body holes were plugged then redrilled to match the new (old) Grabber plate.

I ended up giving the bass to a nice young fellow who was the son of a friend of mine (a single parent Mom and a Special Ed Teacher Assistant ... I'd nail the little fuggars to the wall but she puts up with it). This guy did the work as he is also Uncle to the young man: http://www.vintageguitarman.com/



*Inspired from "Flash Gordon" The Movie. A line by Ming.

[exiledarchangel]

SkuttleFunk used to be a regular poster back on the home planet forum before it exploded but after we boarded the space ship and hurled our bodies out into the void.

Oh man, I really love that description.

[drbassman]

Thanks Al, good tutorial, I need to do the same for my all-maple NR tailpiece.  I keeps pulling out of the screw holes and I tried maple dowels, but now it's pulling  out of those.  I guess inserts are next on my list!

[Pilgrim]

If I do this again, I'll use the drill press to drill the holes, but I may use arm power to screw in the inserts.  That would yield a bit finer control and feel for the process. 

Anyone have an opinion on whether the 8/32 inserts would have been enough to hold the neck securely?  They sure would have taken a smaller bite out of those holes that were close to the sides of the neck.

[drbassman]

So, how do you like th Shop Smith?  I've been tempted to look into one.