New builder, questions about tremolo/bridge alignment and neck angle
Hey all! I recently received my kit (JZ-6). I'm gearing up for my very first build. I started with the recommended mock build and saw a few things I wanted some input on. So the tremolo arm goes into a socket that sticks up between the E and B string, but I noticed on mine the E string is in contact with the socket (see picture). I didn't screw anything in for the mock build so the tailpiece has a small amount of play in the cavity, but not enough to avoid contact with the string. I then looked to see if the bridge was aligned properly, and it seems like it might be slightly off. Visually I could tell the low E string is a little closer to the edge of the fingerboard than the high E on the other side. When I measured it I found it was only 1mm difference (4mm from low E to the edge, 5mm for the high E). Considering this along with the tremolo socket issue, I guess I could try to move the bridge over a little, i.e. plug the holes and redrill them, but that seems like an awful lot of fuss to move maybe 2mm max. I thought I might be able to slightly expand the tremolo cavity just enough that I could shift it so the socket clears the string. I haven't altered anything on the kit, so I could technically return it, but I wanted to see what you all think. Any suggestions would be welcomed!
I also had a concern about the neck angle and string height. I read a recent thread (link) where someone with the same kit found that they had to raise the bridge super high to get the strings off of the fingerboard, and I'm slightly paranoid I might have the same issue. I didn't put the bridge studs in for the mock build, instead I put tape around the inner posts and put those in the holes. The bridge is sitting essentially at it's lowest, and the strings are contacting the fingerboard. I can't really raise the bridge, but I tried lifting the string at the bridge and it seems like it would need to be raised quite a bit to get the string off the fingerboard (see picture). I know having everything unscrewed and loose is not ideal here. With all the strings on at full tension I know the neck will pull forward some and maybe I wouldn't have to raise the bridge an absurd amount. The person in the thread ended up shaving out some of the neck cavity. I'm not sure I have the skill for something like that. Again any suggestions would be very appreciated!
Last edited by redprariedawn; 11-05-2022 at 01:36 PM.
Is the neck screwed on in the pictures? A small change in the neck angle can have a big effect on the required action height.
You may also have a bit of play in the neck pocket where you can move the neck from side to side slightly. This can give maybe 1mm of side to side movement of the strings at the body end of the neck, which can help with aligning the strings. But in your 4th picture, the strings do look fairly evenly aligned down the neck. It's the outside edge of the strings you want to measure from, not the centre of the string. TBH, I've seen far worse misalignments on expensive main manufacturer guitars!
How much movement is there in the trem position itself? even a small sideways movement or slight rotation may cure the string touching the trem post problem.
The design of this type of trem does really benefit from a high bridge position in order to get a good string break angle over the saddles. On a Strat trem, the strings come straight out of the baseplate about 10-15mm back from the front edge of the saddle. But on the Jazzmaster/Jaguar style trem, the strings start a couple of mm off the body to begin with, and a long way back, giving a much reduced string break angle and a source of much anguish and string popping off the saddle moments on the original guitars.
The kit TOM bridge has deeper notches than the original Fender shallow-grooved saddles, so popping out isn't a problem, but you still will want a decent string break angle. Which means that the bridge will need to sit quite high to do so. But there's high and then there's very high. The higher the bridge sits, the wobblier it will be. I often use PTFE plumber's tape wrapped around the post threads to give a solid bridge. It has never seemed to affect the electrical continuity for grounding the strings, as the outer edges of the threads generally tear through the tape and make contact with the post bushings.
If after screwing it on, you think the neck angle still need to be altered so it's pointing down a bit more at the body end, then first check that the pocket and neck are flat and free from sawdust and wood splinters. It doesn't take much height of unwanted objects to make a big change to the neck angle. The distance from the neck end of the neck pocket to the bridge is roughly 4x the length of the neck pocket itself, so a 0.5mm high splinter at the body end of the pocket can raise the point where a straight edge sitting on the top of the neck hits the bridge position by 2mm. Using the same principle, if you don't want to try adjusting the pocket base angle, or the neck heel angle, then a thin shim positioned at the neck end of the pocket can be used to alter the angle so the neck points more towards the bridge and it doesn't need to be so high. I find a single piece of standard hardwood veneer (circa 0.6mm thick) about 1cm x 5cm generally does the trick. You may see a small gap at the heel join, but it's either that or start attacking the wood for a better angle.
If you are doing a solid finish, then you could simply glue a full-pocket length angled shim into the pocket before you start applying any finishing, and then there wouldn't be any gaps. But if a stained finish, then living with a gap may be aesthetically more pleasing to seeing a glued-on shim at the join. You can buy angled shims from a few places, StewMac in the US being the most obvious place, but you can sand your own with a basic jig. I described one method to make your own shim here. You don't need much more than a couple of flat pieces of wood, sandpaper and some suitably thick veneer to sand. https://www.buildyourownguitar.com.a...l=1#post217910
Thank you very much for the quick and detailed response! I've appreciated your insight and experience on many other threads. I'm feeling much more reassured about proceeding. I don't think I'll need to mess with the bridge placement, but it seems I'll have to slightly expand the tremolo cavity in order to get it positioned properly. I'm planning on doing some other routing anyway so it shouldn't be a big deal. It's good to know about needing a good break angle, I hadn't considered that. Thanks for the information on shimming, that's definitely the route I'll take if needed down the road. Thanks again Simon! I'm sure I'll be back on here with more questions before too long.
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