Springs for guitar bending machine

[asbjoern]

Hi,

Do any of you know which springs I need for my guitar bending machine? I mean regarding minimum length, maximum length, diameter and so on? please provide me with the correct information or links to websites where I can buy the correct ones.

[charles Tauber]

The required length depends upon a bunch of factors, mostly related to the geometry of your bender, the shape(s) you are bending and the amount of force required to stretch the spring itself. It depends, in part, on where the springs are attached to the bender relative to the shapes being bent.

My suggestion is to figure out what you need based upon measuring your bender.

Start by identifying where you will place the springs' attachment to the bender. The shortest distance between that attachment point - one for upper bout and one for lower bout - should be with the slider nearest the waist. That way, it takes relatively little stretching of the string to attach the springs to the slider and the spring is stretched progressively further on its way to the upper/lower bouts. Each spring, on each side of the bender should take a "fair" amount of force to stretch it to attach it to the slider when the slider is as close to the waist as possible (i.e. its minimum distance).

Choose a spring that is as long as that minimum distance minus the distance you want to stretch it to attach it to the slider from the spring's attachment point on the side of the bender. Mine need to be stretched about an inch to reach from the attachment point of the side of the bender and the slider. To get that inch, I have to pull on it pretty hard, something about 40 or 50 lb.

With that information in hand, you should be able to go to a hardware store and measure and pull on a few springs to find one that will work for each of upper and lower bouts. You can also get longer ones and cut them to size, if needed, and adjust/bend their ends to attach well.

[murrmac123]

Alternatively, you might want to follow the altogether more simplistic approach of Mario Proulx , who dispenses with springs altogether...

[phavriluk]

I understand the confusion surrounding spring selection. My advice to OP is to review the drawings/instructions that either came with the bender or were used to make the bender. And if the bender was a commercial product, perhaps the builder can be contacted. I could tell the OP what springs I used, but that information would do no good unless the bender was identical to mine.