TB-4 Bass Kit
Hello Builders.
So I'm Currently Building the TB-4 bass kit and the neck fits nicely in the pocket. When I string it up the action is way to high. It looks like it needs a shim to angle the neck down a bit to get the action lower on the higher frets. Has anyone else had this problem before?
Cheers
Hi and welcome.
I’d first check the amount of neck relief. The necks often come with the dual-action truss rods in the ‘neutral’ position. So if there’s a lot of curvature in the neck, first try tightening the truss rod so the neck is almost, but not quite flat. Hold the E string down at the first and last frets to gauge how much relief there is around the 7th fret position. The straighter the neck, the lower the action will be.
But if the neck is pretty much straight already, then a shim is the answer. It’s quite common to need one.
Because a shim at the body end of the pocket angles the neck upwards, you get a far better change in the string height at the bridge compared to shimming the whole pocket and just raising the neck up vertically. So a small 1mm shim should make a change of around 3-4mm at the bridge.
Last edited by Simon Barden; 06-07-2023 at 05:30 PM.
Hi Funguy. I built a TB-4 a while back.
I was proactive with the high action and used some plastic shims. I'm very happy with the result.
The link is https://www.buildyourownguitar.com.a...l=1#post210833.
Last edited by Trevor Davies; 07-07-2023 at 08:40 AM.
PitBull Builds: FVB-4, LP-1SS, FBM-1, AG-2, TB-4, SSCM-1, TLA-1, TL-1TB, STA-1HT, DSCM-1 Truckster, ST-1, STA-1, MBM-1, MBM custom.
Scratch Builds: Pine Explorer, Axe Bass, Mr Scary, Scratchy Tele's.
The little voices in my head keep telling me "build more guitars"
I'm also building a TB-4 that will need a shim. Seems to be a common problem.
All the kits featuring the 3 post bridge seem to suffer the same flaw.
Having to use a shim is still better than the flawed fixed-neck kits which have too shallow a neck angle.
Been watching a couple of utube clips about this very subject, Its understood the neck angles are determined by the thickness of the bridge or rather the set height of the bridge and how far the reveal of the neck heel needs to sit to determine the neck angle with bridge height calculated. This would be essentially the way to determine if a shim is needed or if the neck heel needs to be trimmed down, of course this all depends on which bridge/upgrade bridge is used ???
If you can, I'd stick to shims and not mess with the heel. Shims are much more low risk.
+1.Originally Posted by fender3x
Interesting thinking about the neck angle vs the height of the bridgeBut it does make sense.
PitBull Builds: FVB-4, LP-1SS, FBM-1, AG-2, TB-4, SSCM-1, TLA-1, TL-1TB, STA-1HT, DSCM-1 Truckster, ST-1, STA-1, MBM-1, MBM custom.
Scratch Builds: Pine Explorer, Axe Bass, Mr Scary, Scratchy Tele's.
The little voices in my head keep telling me "build more guitars"
Actually there is more risk in using shims than to trim the heel. But it takes a steady hand and calculations need to be done before attempting a heel trim. The problem with shims is that they can create voids in the neck and pressure will raise the fret board along the lower edge of the neck.
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