Weber Bridge - nut spinning, unable to raise/lower

I have two Weber instruments with a bridge like the one pictured. The instruments are a mandocello and an octave mandolin.

One of the nuts just spins. Won't raise or lower. I'm about to change strings.

Luthiers in my area have a 3 week backlog (if not more) and I have concerts coming up.

Is there a simple issue with this? Typically I only remove half of the strings on one side/replace then half of the strings on the other side/replace to maintain the bridge position.

I live in a climate that cycles between quite humid and quite dry. Do what I can in the winter to humidify the instruments, but still have to adjust the bridge as the top contracts.Attachment 202593

Thoughts appreciated!

If it is holding the strings up, the threads are not stripped. Watch when you turn the nut and see if the threaded part turns also. You may have to hold it if that is the case.

Pops1 is correct. The bolt - the threaded part isn’t stripped, but could be in one place if you’re frequently using the adjustment, which you said you do, but it is more likely that the bolt is turning. To hold the bolt, you have two options. One, if the top of it is visible and it has a screw slot, a small screwdriver is used while you turn the knurled nut. If the top of the bolt is not visible, you need a very good small needle-nosed pliers to grab the bolt below the nut. This may or may not work, and damages the thread as well.
Otherwise, you need to remove the upper (saddle) part of the bridge and either replace the bolt and nut or, if it’s just a turning issue, epoxy the old one in the now worn out threads in the lower part. (Some bridges are built inversely, where the threaded part of the bridge is in the saddle, and I have no idea what yours is.)
Anyway, the principle is that the nut needs to turn on a bolt that doesn’t. If you have another instrument handy, you could borrow the parts temporarily.

With all respect to the two very knowlegeable luthiers above, I offer my non-expert opinion derived from my having worked on several Brekke Traditional bridges on my own Webers.

I am pretty sure that is a Brekke Traditional bridge. It sounds to me like the advice above would be quite good for a Gibson-style adjustable bridge.

The post on a Brekke Traditional can't possibly turn in that design without major obvious damage to the saddle and probably to the bridge and the instrument itself. If the nut turns without raising the saddle, there are three possibilities: a) the nut (wheel) is stripped; b) the post is stripped; c) the saddle (and post) has been raised as far as it will go and the nut is no longer threaded onto the post. Try lowering the saddle and see if it does indeed lower normally. If so, c) may have been the problem and you are lucky the saddle and posts didn't collapse under the string tension once the nut was completely unthreaded from the post.

What to do? I would recommend taking all string tension off, removing the bridge/saddle combination and examining the post and nut carefully to find the problem. If it is a) you might be able to find a simple hex nut at a good hardware store that will fit and work until you can get a replacement from Bruce Weber or Verne Brekke. Take the post with you to the store so you can verify the fit. If it is b) you are probably gonna need a new bridge. Or maybe Bruce or Verne has a replacement for the saddle support / posts. If it is c) again, you might need a custom bridge or at least one that is designed for higher string height off the soundboard. Or maybe shims under the feet might work out.

Again, I am not a luthier, but I have stayed in a Holiday Inn Express from time to time.:)

My first question is do you need to raise or lower the strings at this time? If the answer is no change your strings and make your appointment with your luthier for the future. If you need to raise or lower the strings you are going to have to remove all the strings to examine the bridge anyway. Do the following:

Use blue painters tape to mark out where each end of the current bridge sits. Use pieces of tape on the ends and front and back of those points. Then after you remove the strings use a pencil to mark the bass side of the upper part of the bridge (the saddle) and the lower part of the bridge. I generally put a B in pencil underneath each part of the bass side of the instrument. This way you know where the bridge was and you can put it back in oriented correctly after you are done. I am with Hank on this one.

If you're in a pinch and need to raise the bridge, you could put a piece of wood the right height to prop up the bridge, temporarily making it non-adjustable. There will be an impact on tone and volume since you're adding mass, but depending on the action situation, playability and/or eliminating the destructive impact on tone of buzzing and rattling may be a higher priority.

I have not seen a Brekke bridge in person so will defer to Hank. Sound plausible to me, it looks like it is high,

Thank you for all your wisdom. MN winters cause very low humidity and there's only so much I can do humidifying in the case to help with that. Do the best I can.

Summers are humid.

So, the top does respond to those changes.

I play in the MN Mandolin Orchestra year round, so I do need to make adjustments. Mandocello requires ability to play up the neck without buzzing, and that buzzing is annoying in the winter. So...raise the bridge.

I would like to lower the bridge for now, but realize that come winter, I will probably need to raise it again.

I'll proceed carefully. Have one more summer performance before CMSA, so hopefully I can have a luthier look at it/also purchase a back up bridge from Weber.

"The post on a Brekke Traditional bridge can't possibly turn in that design without major obvious damage to the saddle and probably to the bridge and the instrument itself."

That is true some of the time but not all of the time. The early saddle posts were made from one piece of brass that was cut and then the posts were threaded. If you were to twist the threaded posts, it would break them off.

The newer bridges had a brass bar that was threaded for two 4-40 set screws. The set screws were installed with Loctite (also, the threads were not supposed to go all the way through the bar). If the threads did go through the bar and the Loctite was broken or missing the post could rotate in the bar. In theory, this would split the ebony saddle if the set screw adjusted up through the bar. Screwing the post the other direction would eventually destabilize the saddle.

You can tell the difference by looking at the threaded posts. If they are brass colored, it is an older bridge. If the posts are black, it’s a newer bridge.

I hope that this helps clarify the design changes. As was mentioned, you will probably have to take the strings off to check the saddle posts and nuts. Bruce can probably send you a new bar/post and nuts (the ebony saddle just slips over the brass bar), but I would also take it up with the warranty department at Two Old Hippies.

Vern Brekke
Bridger Products