Is my top caving in?

[Bubby]

Is my top caving in or did I get to much of an forward angle while sanding during bridge fitting? Please help!! Thx!

[BradKlein]

It looks as if one of the posts that hold the saddle is bent or tilted in the base??

[Kevin Briggs]

I agree with the post tilt. Was it leaning prior to you sanding it? I feel like if the top was caving in it would be pretty obvious, or at least it will soon become pretty obvious. I've seen it on a mandolin before, and I actually had a top split on a new instrument once (which Bruce and Mary Weber fixed at no cost as part of the warranty).

Either way, the Builder's section is the right spot for this. :-)

[MikeEdgerton]

I think it's a bridge issue.

[sblock]

From what I can see in these photos, your top is not caving in. Also, the bridge base seems to be more-or-less perpendicular to the top, which is good. However, the bridge saddle (not the base) seems to be leaning forward towards the fingerboard in the first picture (but not so much in the second). This is easily corrected by reducing the string tension and straightening the saddle so that it's in line with the base, then restoring the tension. You can even 'burp' the saddle into verticality without first reducing the string tension (as some folks do), but it's a chancier operation and not for the faint of heart. It's a good idea to lubricate the saddle string slots with some graphite to minimize the tendency to lean when tension is applied.

I am not sure I agree with others who suggested that a bridge post might be bent. It's possible. If so, this is easily checked by removing the saddle and looking at the post. More likely, in my opinion, is that the lean is simply due to the fact the the post holes in the saddle permit some 'wiggle room' for the saddle to lean. This happens on most mandos with a thumbwheel bridge adjustment.

[pops1]

I would agree with sblock.

[amowry]

Yep, I'd first just try pulling the saddle backward (reducing string tension just a bit if you can't do it under full tension), as it looks like there's some gap underneath the back of the bridge base, so the whole thing may be leaning forward. Typically when you install a new set of strings you need to pull the saddle back a few times during the tuning process, as the strings repeatedly pull it forward. If you can't correct the lean just by pulling the saddle backward, you could look into refitting the bridge base. It's best for it to be fit with a little bit of backward lean (I try to bisect the string angle of the bridge, but that's a matter of preference).

[Bubby]

Yea I think some of its that I have sanded way too much off. It was my first time fitting one. Ive played with it and sanded 3 different times so I'd say I've taken off too much.

[sblock]

Yea I think some of its that I have sanded way too much off. It was my first time fitting one. Ive played with it and sanded 3 different times so I'd say I've taken off too much.

I hate to disagree, but looking at the height of the thumbwheels in your photos, I'd say that you did not need to raise the saddle excessively to reach the appropriate action. (This is assuming you'd first adjusted the action to where you wanted it before taking the photos, of course!) That being the case, I would argue that you have not removed too much wood from the bridge base. Which is good news. All you really need to do at this point, I think, is to right the bridge saddle (or lean it slightly rearwards).

[Bubby]

Thx for all the info. I sanded a bit more and got it looking better.