You can make a small block to go under the metal top just under the handle going from top to bottom. Make it longer than the width of the box so that it forces that area of the top upwards and apply the needed stress and angle for the strings. Like the way a arch top acoustic guitar is made.
Do it that way and the top will be free to vibrate the way you wanted. Just make sure the block is braced at the bottom so it doesn't make the bottom pooch out instead of the top.
Comments
Great ideas!
The top will arch some depending on what length piece you cut. That along with the glue you mentioned will keep the block from moving around.
Ciao Paul thanks for the info I'll try that.
I believe that will work the two-component glue to attach the block
You can make a small block to go under the metal top just under the handle going from top to bottom. Make it longer than the width of the box so that it forces that area of the top upwards and apply the needed stress and angle for the strings. Like the way a arch top acoustic guitar is made.
Do it that way and the top will be free to vibrate the way you wanted. Just make sure the block is braced at the bottom so it doesn't make the bottom pooch out instead of the top.
I wanted to leave free to vibrate the plate but the strings were very buzzing. I solved this by making tensor who works as an inverted bridge.