Need a way to shim the bridge

[Dimitree]

Hi guys
Time ago I started building my first guitar from scratch, but then I stopped for several reason. One of the reason was the I made a mistake with the neck angle calculations (it’s a set-neck construction) so now the bridge needs to be raised, it’s too low otherwise, and unplayable no matter how you set it. I’d say it needs to raise a little than 1/4”.
The guitar is a Rickenbacker 330 inspired, and the bridge is original from Rickenbacker. I attached a picture.
Those bridge come with a thin stainless steel baseplate.

I guess there are three ways, I’d like to hear you opinion on which one would be better (mainly to not alter the sound of the original bridge)

1) shim with a piece of wood under the baseplate
2) use a higher baseplate. I already have some thick baseplate that would work, but those are made of really heavy steel and I fear that they could absorb too much vibrations and lower the sustain. Probably a lighter (aluminium?) baseplate would be better?
3) use longer screws between the bridge and the baseplate. I don’t think I’d like this solution since the screws are already quite long

thank you

 

[guitarbuilder]

How about just lowering the neck in the body or is it glued in already? If it is, I'd just get a piece of aluminum bar and make it support the bridge.

 

[Dimitree]

Yep the neck is already glued.

I could use a wood base plate but in that case I’d build a simpler one, not like those used on archtop guitars. Would that make any difference?

 

[Freeman Keller]

If it were my guitar I would make a wooden shim that puts the geometry where it needs to be and not worry about it. Break over angle is important on an archtop because that is what drives the top, on a guitar like a Rick is doesn't matter. You could raise the tailpiece slightly to reduce the angle if you are worried about it. (You can calculate the down force on the bridge - it is two times the sine of the break angle times the string tension. It will often run between 30 and 50 pounds on an archtop.

Also, as you know, your goal is to have the fret plane just hitting the tops of the saddles when they are at their very lowest settings.

 

[schmee]

Is that the pickup rout or the bridge rout? Why dont you just put studs and an ABR style, or other bridge on it either way...?
There are tons of bridge options. A Gretsch Bar bridge is great for sustain and tall.

Thicker the baseplate probably the more the sustain would be my guess.....

 

[kbold]

Another alternative ....... hang it on the wall and start your 2nd build.

The guitar hanging on the wall will be a reminder to check and double check everything before committing.

If the neck or body were particularly time consuming you could separate them by routing/sawing ..... i.e. saving only the neck or body.
You still have half a guitar on the wall as a reminder.

 

[Jupiter]

I suggest that you make a nice wooden base plate, and shape it in a way that is pleasing in relation to the body shape. Then you can say "I meant to do that!"

 

[Jupiter]

option B: can you steam the neck off? 1/4" seems like...kind of a lot...to correct for under the bridge...

 

[epizootics]

I'm with Jupiter here. That bridge seems pretty high already and adding an extra 1/4" would move the strings really far away from your pickups, which at this point could become a problem depending on how you attach those to the body.

 

[mtglick]

option B: can you steam the neck off? 1/4" seems like...kind of a lot...to correct for under the bridge...

This x2. Unless you set it in epoxy, there are lots of vids on YT that discuss how to get a set neck off. Trying to patch the error causes other setup issues, to include lifting the pickups, making the body comfortable at the wrong angle, getting the truss rod to lay relief in the right plane, etc. And you'll always be reminded of it. Actually fixing the problem will solve it. Trying to bodge something together will end up just annoying you every time you play it. Ask me how I know that...

 

[telemnemonics]

With the whole guitar design including the lower section for the tailpiece to afford a less extreme neck angle, I think it's worth resetting the neck to make the whole guitar design fall into place.
It's not just the bridge here, it's the whole guitar.

 

[Dimitree]

Thanks for the suggestions, but resetting the neck is just impossible/not worth.
The guitar is semi-hollow, so I would need to detach the back (1/4” thick) of the guitar from the rest of the body, then detach the neck and put a shim on the tenon. And glue back everything.
I will simply raise the bridge with a solid block of wood.
Pickup height is not an issue, they are pretty high anyway (and can go higher) if you know how Rickenbacker pickups are mounted on the body

 

[Old Deaf Roadie]

I guess my first choice would be to call your local machine/fabricarion shop and have them machine some aluminum, brass, or stainless plate stock to size. Maybe you could come up with a design that doubles as a bridge pickup mount, or something decorative. If it's stainless, have them locate & drill the mounting holes. as well. That will afford a stable, solid base. You can also use the same approach with a hardwood spacer instead of metal. You may need to elevate your pickups, as well.

 

[Boreas]

Choice #1.

I personally would use the exact hardware you pictured, and use a rock maple spacer GLUED solidly into the base of the rout. To me, that would maintain the desired tone quite well.

 

[old wrench]

Seeing as re-setting the neck is out - I'd go with a thicker base plate - aluminum is easy to work with, and I can't think of any reason not to use it.

What I would do is make some improvements to your bridge design, and take my cue from the design that Mastery uses for their Rick bridge

Check out the link -

Rickenbacker Bridge + Guitar Parts | Mastery (masterybridge.com)


.

 

[Dimitree]

today I tried with a 5mm stainless steel base (under the original base). Now with the bridge set halfway, it's fine. Also the pickup is just about at the right height (using its original foam spacer).
I will then use a 5mm piece of Padauk wood, since it matches the fretboard and looks better than the steel I'd say.

 

[rexhunta]

The spacer doesn't look out of place at all, looks like it is meant to be there. If you polish the sides with 1500-2000 wet and dry it will look like the rest of the bridge.

 

[stratisfied]

Nice save! Looks just fine.

 

[Dimitree]

I’ve made the spacer using maple. Then put the strings on, adjusted the nut and the action, turned out great. And it seems that I have lot of margin for bridge height adjustment, so I probably will lower the spacer. The action is still pretty high, so that’s great. Don’t know how it sounds compared to no spacer, but sounds great enough to me (specially for a first build).
definitely a keeper, not a guitar to hang on the wall, despite the mistakes