Bridge plates when using pinless bridges

[phavriluk]

I have it in mind to use a pinless bridge on a project. I haven't been able to document what differences, if any, attend a pinless bridge as compared to the bridge plate used on a conventional pinned bridge. The various construction plans I've obtained all are drawn for a pinned bridge, and I don't know what design adjustments go with using a pinless bridge.

Any advice, explanation, or warnings, will be gratefully appreciated.

Thanks, folks.

[Ned Milburn]

Originally Posted by phavriluk

I have it in mind to use a pinless bridge on a project. I haven't been able to document what differences, if any, attend a pinless bridge as compared to the bridge plate used on a conventional pinned bridge. The various construction plans I've obtained all are drawn for a pinned bridge, and I don't know what design adjustments go with using a pinless bridge.

Any advice, explanation, or warnings, will be gratefully appreciated.

Thanks, folks.

My Evo bridge design is pinless, but I used bridge plates in all builds. I used spruce to double thickness the top in an area greater than the bridge footprint. This can be seen as an aide to stabilizing the bridge to top glue joint, and to help avoid severe soundboard warping.

[dekutree64]

You don't really need one at all. A lot of classical guitars use a thin softwood bridge plate, which I think is to balance the force generated by humidity expansion/contraction to keep the action more constant throughout the year. May not be as necessary on steel strings, since the X already provides some cross grain gluing on the inside to counter the humidity effect.

You could use a softwood bridge plate that extends 1/2" or so behind the bridge to reduce peeling stress on the bridge glue joint (feather out the stress riser). Or fan braces in the south quadrant, which provide similar support for the bridge. Especially good for thin soundboards. Trevor Gore's falcate pattern is another that has braces running underneath the bridge, which are tricky to position if you need them to pass between bridge pin holes.

But it would also be perfectly fine to leave the bracing pattern completely unmodified from what it was with a pinned bridge.

[Alan Carruth]

Many Classical guitars use no bridge patch at all, and don't seem to suffer for it.

IMO the main purpose of the bridge plate on a steel string is to provide a hard surface for the ball ends of the strings, so they don't cut into the top too fast. This is not to say that the bridge plate has no secondary functions, such as stiffening up the top and providing some degree of 'balanced construction' in that area. Structurally it's probably not necessary so long as other design elements take care of those functions reasonably well.

[phavriluk]

Thanks, folks, for the comments and conversation. I'm tempted to do without, the bracing scheme I was copying would be much simplified without a bridge plate. And I could find out whether I was building too light or not.