neck stability help!

BarkerBass · #1 02-04-2008, 04:42 AM

Earlier this month i got my college build project bass guitar out for the first time ina while and saw its action was huge and neck had alot of bow so after a while of tinkering and alot of truss rod adjustment i got the action nice and low and even and since then it has played great. however, when i tried playignt his morning i noticed the action was once again massive yet the bridge was still set up in the same way etc. so iv come to the conclusion that my neck pocket/connection must be moving or looseing since all hardware and the truss rod remain the same yet the action worsened.

all that has changed since my first tinker is a releltively new set of strings, is this a possible cause? can they really cause a neck to bend even if truss rod is fully tight?

i must state that my bass is a 4 string headless with a 24fret mapleneck bolted to the body with 4 hefty woodscrews through a neck plate, would changing the screws be of any benefit?

is there anything i can do to improve the situauion or is the bass doomed to a life of neck problems?

Andy

Nelson Guitars · #2 02-04-2008, 07:12 AM

Truss rods are designed for adjusting relief not action. Although they will effect the action that is not their purpose. You most certainly need to check how secure the neck is to the body. Perhaps the wood screws have stripped? In that case you will need to install some threaded inserts.

Another possibility is that the fret board is not bonded well to the neck. Check to see if the finish is cracking along this joint. An indication that the FB is creeping along the neck.

Keep us posted.

Greg N

BarkerBass · #3 02-04-2008, 10:54 AM

the reason i adjusted the truss rod was because the neck had alot of forward bow and this solved that however i know think it had just shifted in the pocket and was leaning forward.

what are these threaded inserts of which you speak?

the fretboard is well attached and no cracks visible.

would adding another screw, say in the centre of the plate/pocket aid in stability or would that increase the chance of splitting the wood and other problems?

is it possible to buy wider threaded screws to get a better hold/tighter joint since the current screws appear to be loose and not staying tight for long?

i did notice while changing strings that when the strings were on but not at the correct tension the neck was angled backwards quite alot but his was countered by the tension of the strings to produce a low action, is this "wrong"? should the neck be that susceptable to tension and movement? none of my other basses have this issue so im guessing its the DIY nature of the neck joint thats causing it

Nelson Guitars · #4 02-04-2008, 12:23 PM

Take the strings off, pull that neck off and look inside. I have a feeling you will find your solution if you do that.

Threaded inserts are small bushings with wood threads on the outside and machine threads on the inside.

Greg N

BarkerBass · #5 02-04-2008, 06:06 PM

Thanks, what would looking show me? or do u expect to show me? also do u know where i might get these inserts and do they then work with bolts since they have machine thread on the inside?

cheers

Nelson Guitars · #6 02-04-2008, 07:01 PM

I think you will find that once you remove the tension of the strings you will be able to wiggle the neck around If you can tighten the screws and fix it your are in good shape. If you turn and turn the screws you will know that they are stripped. If you remove the neck you may find some debris inside the neck pocket that is causing the problem. You never know. Mostly I am recommending removing the neck as a means to discovery.

Here is a link to a threaded insert for bolt on acoustic necks from LMI. http://www.lmii.com/CartTwo/thirdpro...n+Neck+Inserts
These are available in many different shapes and sizes these days at good hardware stores. Maybe not the home despots, but good hardware stores.

Greg N

BarkerBass · #7 03-02-2008, 05:57 PM

Just a quick update if anyones interested in that i ordered a set of inserts for larger bolts and installed them this last weekend, i had to enarge the neck and neck pocket holes to accomodate the inserts and the larger bolts but toatlly worth it, the neck is now stable and has koped well with all the actiona nd truss rod adjustments i did to get it playable and its now easily removeable should i ever need to!

the eonly down side is that the bolt heads are slightly bigger than the counter sinks in the plate so they arn't flush and arn't black either but i aint too fussed it works!