Tricone height change under strings tension

[Pierre-Antoine Roiron]

Hi there!

I'm currently building a tricone inside an electric guitare with a Firebird shape for a customer. Does anyone have a tricone here and could measure the difference of string height when tuning up to pitch on a average string gauge? I'd like to estimate if I have to take that into account that change in bridge height in my design. Unfortunatly, I only have a single cone biscuit bridge here, and I doubt results would be relevant...

Thanks for any help.

[Russell Vance]

Hello Pierre Antoine,

Firstly, hubcap guitars are the work of the devil and you must be strong if you are to triumph over the rattle and intonation demons. 

Having said that I strongly advise you to make the instrument a bolt-on neck if it isn't too late, that way you can adjust the neck for tilt and parallel shim for height adjustment (intentionally make the neck pocket deep and shim to bring it up to spec, this way you can change geometry by removing/adding shims)  - this will allow you some wriggle room in the geometry and also allow the instrument to be set up for slide further on if necessary.

If you have it as a set neck please Email my collague Barron Clarke at;   [e-mail] and mention my name as a referee - he may be able to help you as he is all things resophonic and knows his stuff well.

Good luck Comarde, tell us how you went.  Russell Vance (Rusty)

[Pierre-Antoine Roiron]

Thanks for your help Russell! I will consider the clever bolt-on option. I'll send an email to Barron Clarke when my design will be near completion.

I don't fear intonation problems, as the whole bridge will be homemade : I can slightly move it to suit my needs. It should be completed this summer. I'll send pics for fun because it's a strange beast.

[Ned Knepp]

This may be a bit off subject but I'm curious.  What sort of pickup do you use to amplify a resonator and still keep that "tin can" sound that they produce?

[Pierre-Antoine Roiron]

There are not a lot of pickups to use for a tricone. I chose the one made by Highlander, and some preamp will allow a mix with regular single oils pickups. The "tin can" sound would be reproduced by the highlander and the fact that strings vibrate a special way the only tricone produce. Well I hope so!

[John Morton]

The downwards deflection from string pressure on a tricone is slight, certainly less than 2 mm.  It is much more noticeable on a single cone.  The downwards force does vary with the angle the strings form over the saddle ("break angle"), but those 6 in. cones just don't compress very much in any case.

I think you would be safe in planning for zero deflection, and then making a saddle higher as needed when you string it up.  I always figure a saddle is OK anywhere from around 6 mm. to 15 mm. in height.  The break angle can be very small, but I would provide 5 degrees or so to insure against buzzing.

I will be interested to know if you find a pickup you like. 

good luck

John

[Pierre-Antoine Roiron]

Thanks John for this input, I'll take your estimates into account for my design. I'll try to come back with some sound files too when it will be completed.