Shimmed neck on my old Framus

[effzee]

Boreas suggested starting a separate thread, and I guess that's what I'm doing

Post in thread 'First Time Neck Shimmer' https://www.tdpri.com/threads/first-time-neck-shimmer.1122221/post-11740331

Not really much to say now. The guitar is my 1965 Framus Atlantik 6 semi-hollow. I really like the bridge on it, if mainly for the optics; it just looks cool and matches the string pusher-downer-bar on the whammy tailpiece. It also intonates perfectly, like magic

It has two thumbwheel adjusters to adjust the action, and they were both all the way down, no way to lower the action further (neck relief is spot-on).

The action is absolutely okay and the guitar plays beautifully, but I felt there was still some wiggle room on the action, it could go lower, except the bridge was stopping that.

So it seemed the solution could be a neck shim. As in the the other thread, I've never done it and really thought it was too complicated for a dummy like me. But then that other guy said he used the top of a cereal box and someone else chimed in saying a matchbook cover would have more mojo (that's how I remember it), and I thought, what the hey, sounds like something even I could handle and the chances of destroying my guitar are negligible.

So I took off the neck (loosen strings, secure them with a capo, boom).

There was already a little shim at the front, which to my non mechanical engineering brain was doing the exact opposite of what I wanted. The guitar is coming in on 60 years of age, so who knows who did what for what reason in the past.

No problem. I just moved the little shim to the other end of the neck pocket, bolted it back together and, taa daa, the strings pretty much bottomed out on the fretboard. Remember though that the bridge was already cranked down as far as possible. So I twiddled the thumbwheels to raise the action and it feels great so far.

But I'm writing from the car while waiting for my wife at the PT. I won't have a chance to really check the difference till later. But now I do have some room to play with as far as bridge height is concerned.

The neck pocket is a lot smoother than the over-sharpened pic suggests @Boreas

The shim in the original position:

The bridge, a solid piece of machined steel:

I forgot to take a pic after moving the shim but it's just on the other side now. Might just not need it at all

 

[Boreas]

My guess is if you just wanted to move the bridge a gnat's eyelash, simply removing the shim would be enough. Depends on how much adjustment you want/need. I would be inclined to try it sans-shim for a while.

Keep in mind, a higher bridge means more break angle. This can be a double-edge sword with a whammy system. Higher break angle equates to more friction over the saddles. This can impede the guitar returning to tune after wiggling. On my Bigsbys, I usually try to get the lowest playable bridge I can to ensure good tuning stability. Just something to watch out for.

 

[effzee]

My guess is if you just wanted to move the bridge a gnat's eyelash, simply removing the shim would be enough. Depends on how much adjustment you want/need. I would be inclined to try it sans-shim for a while.

Keep in mind, a higher bridge means more break angle. This can be a double-edge sword with a whammy system. Higher break angle equates to more friction over the saddles. This can impede the guitar returning to tune after wiggling. On my Bigsbys, I usually try to get the lowest playable bridge I can to ensure good tuning stability. Just something to watch out for.

Hmmm ... Very interesting, thanks, I would never have considered that "angle", but first chance I get, I'm going to do a closer examination of all this.

I mean like, this evening, lol. I'm not that busy.

 

[Freeman Keller]

I believe that in the other thread I linked my discussion on geometry. When a shim is put in the front of the pocket as you've shown it lowers the strings with respect to the frets. Most of the time people do that when they have adjusted there bridge as low as it will go and the action is still too high. As I think I said in the other thread, when I build a guitar my goal is to have the fret plane just hitting the top of the saddles when they are all the way down, that generally allows you to raise the bridge/saddle assembly to a reasonable height and get reasonable action.

 

[effzee]

I believe that in the other thread I linked my discussion on geometry. When a shim is put in the front of the pocket as you've shown it lowers the strings with respect to the frets. Most of the time people do that when they have adjusted there bridge as low as it will go and the action is still too high. As I think I said in the other thread, when I build a guitar my goal is to have the fret plane just hitting the top of the saddles when they are all the way down, that generally allows you to raise the bridge/saddle assembly to a reasonable height and get reasonable action.

But, wait, isn't it just the opposite? That's what I just figured out by simply moving the shim to inside the pocket. That's what lowers the strings in relation to the frets. In fact, when I did that, the strings bottomed out on the frets, allowing me to raise the bridge to get the action I was after.

What I'm describing could be stimulated by the headstock to the rear of the guitar. That raises the pitch and lowers the "action" so to speak. Same thing happens when the shim is in the back of the neck pocket.

If you push the headstock from the back, the strings rise and the pitch drops. And that's like having the shim at the front of the pocket, as in the photo I posted.

??

 

[Freeman Keller]

Yes yes yes, you are correct. I looked at the picture but spaced out which way you had moved it. You want the thicker part of the shim towards the bridge. I'm sorry and stand corrected.

 

[dsutton24]

There is a lot of agonizing over neck pocket shims around here, and it's hard to understand. It's easy, it costs nothing, it's reversable, and it's proven to work. But for some reason easy makes some people suspicious. I live for easy.

 

[Monoprice99]

When I fabricated a hard plastic shim, I read online and worried about the gap(s) between the neck heel, the shim & the neck pocket as my primary concerns. That's why I chose to make a shim for the entire 3 inches of the neck pocket bottom front to rear. That way it was either conceptually a thicker & properly angled neck heel or thicker tongue with a proper neck angle for the neck pocket. Had enough material leftover that I made a Tele shaped flat shim & the one that needed the shim was a HT Strat. That way I can just shape the unused shim and also sand it smooth and to the thickness necessary for the next guitar that needs a shim as a project.

 

[effzee]

Yes yes yes, you are correct. I looked at the picture but spaced out which way you had moved it. You want the thicker part of the shim towards the bridge. I'm sorry and stand corrected.

It dawned on me after I replied that that's probably what happened. But by then I was off to sleepy time

 

[Boreas]

There is a lot of agonizing over neck pocket shims around here, and it's hard to understand. It's easy, it costs nothing, it's reversable, and it's proven to work. But for some reason easy makes some people suspicious. I live for easy.

With different bridge and saddle types, shims often are a necessity - unless you have the Tilt-o-neck feature.

 

[effzee]

There is a lot of agonizing over neck pocket shims around here, and it's hard to understand. It's easy, it costs nothing, it's reversable, and it's proven to work. But for some reason easy makes some people suspicious. I live for easy.

Yeah well, surprise surprise, not everyone has done everything already. Some people who are clearly not in your league are discovering some things for the first time. There are currently 2 (two) members here talking about shims. If you think that constitutes "a lot of agonizing", I'd love to hear your thoughts on really big numbers, like 5 (five) or 8 (eight).

 

[dsutton24]

Yeah well, surprise surprise, not everyone has done everything already. Some people who are clearly not in your league are discovering some things for the first time. There are currently 2 (two) members here talking about shims. If you think that constitutes "a lot of agonizing", I'd love to hear your thoughts on really big numbers, like 5 (five) or 8 (eight).

That's brilliant! You're definitely in my league. 42 is good.