Re: Crazy project #1: variable-pitch pullrods for JI tuned PSG.
Posted: Wed Feb 17, 2010 9:22 pm
To illustrate the madness a little: as rough sketch of what the lever mechanism behind "movable holes" for a variable-pitch bellcrank axle may look like...
![Image](http://www.gunlaug.no/msc/img/varpitchaxle.png)
It will replace a regular bellcrank axle, and the only difference is that the axle is shorter than the others and that it can rock back and forth a little based on what's pushing at either end of the long lever.
Exact shape and bending away from the cabinet-side depends on how many such variable-pitch bellcrank axles are needed in a PSG and how close they are to each other. 1-3 such axles will be needed in PSGs with JI tuning over pretty standard copedents.
I want to put flanges on those "cams" so the levers can't slip off, and I haven't drawn the spring-loading on lever or "cams" necessary to handle pushes from "cams" on both sides simultaneously.
Again: anyone see problems with the idea and the basic mechanics here..?
![Image](http://www.gunlaug.no/msc/img/varpitchaxle.png)
It will replace a regular bellcrank axle, and the only difference is that the axle is shorter than the others and that it can rock back and forth a little based on what's pushing at either end of the long lever.
Exact shape and bending away from the cabinet-side depends on how many such variable-pitch bellcrank axles are needed in a PSG and how close they are to each other. 1-3 such axles will be needed in PSGs with JI tuning over pretty standard copedents.
I want to put flanges on those "cams" so the levers can't slip off, and I haven't drawn the spring-loading on lever or "cams" necessary to handle pushes from "cams" on both sides simultaneously.
Again: anyone see problems with the idea and the basic mechanics here..?