Strings popping out of the nut groove....

[leftybass]

Mark, I have one string (sometimes two), A and E specifically on my 1972 4001 that tend to jump the groove in the nut....the only thing I have done to compensate for this is to draw the string down lower on the machine head to allow more downforce across the nut. Most of the time this works but would there be a more permanent fix?? The nut is the original white composite nut and I use .40-.95 light gauge strings. And I dont think I hammer on it hard enough to pop it from the groove. Any ideas????

[leftybass]

Also, my '79 has the phenolic nut which has higher sides and therefore deeper grooves..is this why they went to this style, or maybe the nut on the '72 is just worn out....?

[markthemd]

The nut slots were cut using a half round file .This works okay for the most part and in production did the job well.The initial notches were cut using a saw.Some of these old nuts have the saw cut almost to the fretboard.The file cuts stop way short of that.
The problem is the walls of the nut are slopping toward the bass side of the neck and the pressure of the strings is also pulling in that direction.

To fix this ,you need to replace it .I use several parallel round files .Except for the .060 slot of the "G" string These work great.I use a saw to start the slots and get the spacing using a set of dial calipers.

Then the slots are cut verticle.This way the string can not pop out.By using a round file ,the string always sits in the bottom of the slot.NO PINGING!
I cut the slots about .015 oversized.I leave the top of the nut flush with the top of the strings on Rick basses.This is due to the low neck/headstock angle.

[leftybass]

Many thanks, Mark. I'll look at it closer and start looking for a proper nut....

[markthemd]

Chain saw files and gunsmith files are a great supplier for these types of files ,they generally can not be had at most typical hardware stores.