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Here's a very craftsmanlike new bridge, just completed by Matt O'Brien.

This was posted to the CoMando list on August 20th.

Scroll on down for Matt's writeup after weather changes affected the bridge's fit to the top.




Hi everyone and especially Red!

OK - I've done it. I made a solid bridge and its great! Increased tone, increased volume, and the whole top vibrates! In fact the top was buzzing, and I found there was a loose screw on the pickguard which I had never noticed before, and certainly had never heard! One word sums it up - WOW!

I've put some photos and some info on my website: http://www.mafudesigns.com/mandolin/buildbridge.html

Red, thanks - now I hope to play with my own designs and contribute to the learning curve. Feel free to use of the text/photo for your site, and let me know if you want a larger scan of the final bridge.

Cheers,

Matt



These are photos of Matt's bridge which he posted on his website. We recommend that you visit his site (address above) for a more extensive writeup.











...and here's a post which Matt wrote on Saturday, August 24th, having to do with the top-swelling and bridge-foot fit problem:


Hi Everyone,

Just a follow up post on my solid bridge I just made - this may have some information that could be useful to some of you.

As you may recall, I made a successful solid bridge, it played well, and I think looks good. The details are all on my website.

Two days on, the bridge suddenly sounded "dead" - and I was very confused at first. Then I looked at it, and the feet had lifted at the ends as a couple of others have reported.

Initially, I spent a long time getting a good fit, and ensuring the fit was good even after tension was applied through the strings. So I know I had it right to start with.

I pulled the strings off, and the ends of the feet still stayed lifted up - so obviously something went wrong. I refitted the bridge, all the time thinking about structural stability - I had all sorts of things going through my head:

"Maybe I thinned the feet to much - but they are still thicker than my adjustable bridge." "Maybe the wood had a weak point, and suddenly the weak point collapsed, causing a small change in shape" "Maybe I rested my palm on it to hard when I was playing" "Maybe I play to hard".

So I finished fitting the bridge again, and the sound came back and all was good. So I sat down on the couch to play, watching the rain outside.

"Rain?"

Hang on a minute.

I'm in Queensland Australia, and we have had about 3 months without rain, so its been dry as anything. I got the maple about a month ago, and let it acclimatise for the month here. Then I resawed it one day, cut the bridge the next, and then fitted/compensated it another day later. All was good.

Two days ago it started raining, and it hasn't stopped since. Well, it stopped this morning. Anyway, even though the mandolin is inside, and kept in a case, I think the bridge/mandolin has absorbed water, and so has swelled ever so slightly - which of course is noticeable in a 0.25mm gap at the ends of the feet.

I've been emailing with Red, and he agrees:

"Yes, yes-- I didn't know about the weather. Many good mandolin tops will soak up that wet weather like a sponge, and expand, thus raising the action -- and if the bridge was fit to the top in its lower, flatter, state, suddenly the fit isn't there any more. I think you have nailed it.

"I have this happen early every summer, when the more humid weather hits. I haven't had a chance to see what it does to the maple bridges' top-fit since I only began making the bridges in late June, after summer was well under way here and my mandolins' tops had already swelled up in the customary way.

"This fit problem normally doesn't show up with the adjustable bridges, most of which have thinner, more flexible feet. It may be that a maple design can be found which shares that foot-flexibility. No way to find out but make some bridges with different feet... might have to do that."

Just for everyone's info!

Matt





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