Steel Guitar Builder

I was talking to someone in the local music store the other day about pull-release changers. He had asked how they work. I showed him Burt's sketch and for some reason he couldn't get the hang of it at all. I thought it was perfectly clear. Anyhow, I decided that a moving graphic might help. I will try the guy again with this version.
So, with all credit to the originator, here is my version of the drawing. Hope you are OK with me using yours for inspiration Burt... Feel free to use it/copy it/change it if you want to.

That's excellent, Allan

There is an even simpler form of pull-release, that only uses one rod, for both raises and lowers.

Imagine that the bellcrank for the lowers is spring-loaded (instead of a spring-loaded lowering rod), and the collar for the lower is on the other side of the bell crank than it is at the moment.

Thus, the spring-loaded bell-crank holds the finger in the central position, and string tension causes the finger to lower (when the bell-crank is released). The raise is simply pulling the rod away from the bell-crank.

Can you draw that scenario, Allan ?

I'm a fairly mechanically savvy guy and did indeed already understand Burt's diagram, but animations like these are awesome...it'd be really cool see this type of animation of some of the interesting changer designs I've been perusing in old patents...trying to figure out what's going on from the patent drawings (or from reading the legal patent mumbo jumbo) on some of them makes my brain start to hurt!

Funny aside....it looks like after 2.5 years a patent will issue soon for a bit of bicycle hardware I'm involved with. I invented this thing, but for the life of me would not be able to tell WTF it does by reading the patent...the pictures in this particular patent app. make it fairly clear, but the verbiage...egads! I'm told that patent legaleze is somewhat of its own language.

Thanks Allan!

burt wrote:That's excellent, Allan

There is an even simpler form of pull-release, that only uses one rod, for both raises and lowers.

Imagine that the bellcrank for the lowers is spring-loaded (instead of a spring-loaded lowering rod), and the collar for the lower is on the other side of the bell crank than it is at the moment.

Thus, the spring-loaded bell-crank holds the finger in the central position, and string tension causes the finger to lower (when the bell-crank is released). The raise is simply pulling the rod away from the bell-crank.

Can you draw that scenario, Allan ?

Now I know how the guy in the music store felt! Can you make a sketch of that? If you can, then I will do an animation like the one above. DUH me!!!

This is what I mean, Allan

Can have animated tunable splits with that?

burt wrote:This is what I mean, Allan

OK, now I get ya... The complexity just moves over a bit as I see it. (OK, it's not complex really - just a relative term.) What I am referring to is that there needs to be some free movement available on the pedal rod/knee lever used for the raise so that it doesn't move when doing a lower. That doesn't seem to be complicated in its self but it does need to be considered. In other words there needs to be a gap somewhere - either as at the right hand end of the raise (relative to my drawing), or somewhere else in the linkage, to allow for the lower to happen without affecting the raise linkage train.
I am aware of the limitations of the pull/release system (so is Georg!!! LOL) but I am also a fan of simplicity.
Thanks Burt, I will take a look at that concept.

Allan.....

The free movement would be at the raise pedal/lever bell-crank.

I have something similar on my Marlen sixth string lower, I just have to remember to raise my left foot slightly to allow the B pedal to come up when I activate the lower (with a knee lever)

OK! Now I'm excited love the simplicity. An animation would be awsome.

Working on it guys.....