Wednesday, March 05, 2008

cigar box guitar bridges saddles

As requested here's some info on bridges/saddles. First some principles as I understand them. The bridge/saddle is the main component that transfers the vibrations of the strings to the soundboard, in our case the cigar box lid. The most efficient materials are dense ones. Having said that the traditional material for acoustic guitars is bone which is not as dense as metal but I don't know why it is favoured. A CBG is never going to compete with a Martin or Gibson on sound quality but we do want to try to get a decent volume and tone out of it, given its limited capability, so it's worth experimenting with different types. Personally I like to use as much recycled material for my CBGs as possible. I have mainly just used scraps of hardwood like oak and mahogany and shaped them into an upside down "T" cross-section shape. I made one out of aluminium for the Quality Street tin and that worked well too. My last CBG had a bridge made from bamboo and aluminium and that also worked.

I think the positioning of the bridge on the soundboard must also have some bearing on the sound. I have seen many CBGs with the bridge placed right down at the bottom of the guitar. I haven't tried placing it there myself as logic tells me that the most sensitive area of the lid must be near the middle. I opted for a position about 2/3 down the lid which is roughly where most acoustic guitars have them. The guys that build them must know a thing or two so who am I to argue.

Another issue that may be of interest to the builder is how to secure the ball end of the strings as most modern acoustic guitars have the plastic pin arrangement in the bridge. Well most CBG builders adopt the "straight through neck" design. This lends itself to fairly easy construction and the facility to leave a short "tail" at the bottom of the box to anchor the strings to. Simply drill small holes to pass the strings through from underneath. I have included a small metal plate to take the strain of the strings off the wood, which would otherwsie tend to cut into it. Hope this helps.


sam two said...

yeah that helps alot thanks. i'll try and use those ideas with mine. building right now. i knackerd from all the filing! the bridge is a long way away but i'll cross that bridge when i come to it. sorry

David said...

cool. maybe you could send a photos when it's finished