Break Angle of strings on an RM-1

  1. Driftwood
    Hello everyone,

    Could some kind people measure the break angle of the strings over the bridge on their RM-1s for me? I know this isn't that easy with the resonator cover plate in place and I realise the angle will vary slightly from one mando to another depending on how high the string action is - but any info. will be gratefully received. I think the angle is very small, somewhere between 4 and 7 degrees perhaps?

    The thing is I can't afford an RM-1 at present but I do have a spare 9.5" cone and some wood so I'm heading into the workshop!
  2. Shelagh Moore
    Shelagh Moore
    I will try to do this but will need to set something up to measure it accurately. I lowered the action on my RM-1 quite substantially to my personal tastes after I bought it and, while the mandolin still sounded OK, I felt the break angle then wasn't quite sufficient for optimum tone. I therefore glued a strip of hard leather under the leading edge of the tailpiece which added two or three more degrees of break and I've been happy with the lower action, setup and sound since I did that (a bit over a year ago). From memory I think someone in this social group has also physically bent the tailpiece downwards to increase the break angle
  3. liestman
    I admit to being the aforementioned tailpiece bender and it has worked out quite well to get the break angle back to I think what the maker intended but still to have nice low action.

    I hope you can use this. I have nothing to measure the angle with but I took a pic with all the strings in the same plane as the camera lens and added it to the group pictures. At this break angle, the note clarity and sustain are wonderful (too small an angle - pre-bend - and the clarity left the building)
  4. Driftwood
    Thanks very much Richard and Liestman. I was going to suggest one of those adjustable "squares" if you had one (but probably a risk of scratching your precious RM-1!) but the photo is an excellent idea. I put a transparent protractor over the picture and estimated the angle at 4 degrees. I would be inclined to design for a slightly higher angle as it can always be reduced. Also I imagine the cone depresses slightly when under string pressure.
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