The cabinet will flex the most in the center. When pushing the pedal, the pedal bar will push upwards with the same amount of force. The 5th leg will push the center of the cabinet "up" with the same amount of force that is applied to the pedals. I don't know if it completely cancels the cabinet drop. An advantage of this system compared to others is that the pedals don't get stiffer.Lynn Kasdorf wrote:I can't see how this leg/rod will help at all. No diagonals.
What would work to reduce cabinet drop is to have a Vee shape. Have two rods attached at the extreme ends of the cabinet at the top, and meeting in the middle of the pedal bar. This would make the pedal bar more rigid.
Or, just a simple, very short "leg" going between the middle of the pedal bar and floor.
5-Legged Steel Guitar?
Moderator: Shoshanah Marohn
- Marco Schouten
- Posts: 1866
- Joined: 30 Mar 2000 1:01 am
- Location: Amsterdam, The Netherlands
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JCH SD-10 with BL XR-16 pickup, Sho-Bud Volume Pedal, Evidence Audio Lyric HG cables, Quilter Steelaire combo
JCH SD-10 with BL XR-16 pickup, Sho-Bud Volume Pedal, Evidence Audio Lyric HG cables, Quilter Steelaire combo
- richard burton
- Posts: 3846
- Joined: 23 Jan 2001 1:01 am
- Location: Britain
The pedal is a second class lever, just like an upside-down wheelbarrow
When the pedal is pressed, the load is trying to pull the body of the steel and the pedal bar closer together. This 'pulling together' can be minimised by adding a strut (5th leg) between the body and the pedal bar.
The pedal bar can now be considered to be part of the bracing/strengthening of the body.
When the pedal is pressed, the load is trying to pull the body of the steel and the pedal bar closer together. This 'pulling together' can be minimised by adding a strut (5th leg) between the body and the pedal bar.
The pedal bar can now be considered to be part of the bracing/strengthening of the body.
I think Mr. Georg Sørtun is correct
The steel guitar body is a beam, loaded by tension in the pedal rods. As a structural engineer familiar with beam theory I believe Mr. Sørtun is exactly correct. His point is succinctly and elegantly stated.Yes. However, the way (I personally think) is should be done is to not have the carrier/frame that holds the mecanics inside the tone-body attached along the entire length of the front and rear aprons, but only at both ends where it is fully supported by the legs. Then the mechanics will be allowed to flex a little vertically with pedal pushes, and the tone-body itself will stay straight and unaffected by vertical stress.
Because of the way the bellcranks and pull-rods work, vertical flex in a more "free-floating" mechanics won't be transferred horizontally to the changer, thus that cause for bodydrop detuning will be eliminated. Then only the effect of changes in string tension when pedals/levers are pushed will remain.
It is a little counter intuitive. It is easy to think that more fasteners will provide greater stiffness; but decoupling the mechanism from the cabinet, as Mr. Sørtun suggests, seems to me to be a more rational solution. I don't see why manufacturers have not adopted (or at least tested) this approach.