Is the current Sierra a knife edge changer?

[John Hyland]

based on this picture from the Sierra website the changer looks like a blade design. Also, the site mentions single changer removal which is a knife edge feature. .
http://www.sierrasteels.com/images/gall ... s-11-l.jpg

If this is true - any pictures or schematics as I didn't really understand the description of the floating pivot.

[Daniel Morris]

You could try contacting Ross Shafer, the builder, who is on the Forum.
A gracious guy who could certainly fill you in.
(I have one of the new Sierras, but I'm afraid I don't know the answers to your questions.)

[John Hyland]

Thanks Daniel. Maybe Ross might chime in.

[Ross Shafer]

The modern Sierra steels do not incorporate a “knife edge” pivot. That said, they might’ve if I hadn’t come up with the design I do use. Each finger is on its own 3/32” pivot.

[John Hyland]

Thanks Ross. I thought I could see a possible pivot just above the surround.

[John Hyland]

Ross. Does that mean your design essentially moves the top changer laterally rather than rotating?

[Tim Toberer]

John the way understand it is, it is like a knife edge, but instead of a sharp knife the pivot has a radius of 3/32. (But I could be wrong) My thoughts are an actual sharp knife edge would cause wear on the finger or the knife edge, so a small radius is preferable. I am pretty sure this is a problem with the Fender guitars, not sure about Blanton.

[John Hyland]

. Each finger is on its own 3/32” pivot.

Tim. I’m not really understanding this comment. It suggests each finger is somehow independent. if you look closely at http://www.sierrasteels.com/images/gall ... s-11-l.jpg you will see what is possibly the pivot behind the flat panel in front of changer. Indeed is that flat panel part of the changer or a cover plate?

Also to me a knife edge doesn’t mean a literal sharp edge but a minimal radius

[Ross Shafer]

hi guys, I'm not ignoring you. I just lost a lot of writing (twice) answering your questions whilst trying to attach a pic.....arrrgh. Don't have it in me right now to type everything yet again, but maye I can attach a pic that'll answer your finger pivot arrangement without losing this message.

I'll try to get around to answering your other questions regarding "floating pivot" and "lateral movement" another time.

IMG_1554.jpg

[John Hyland]

Thank you Ross for persevering

[Ross Shafer]

Well hot damn! I managed to find an old post of mine describing how the Sierra changer works....much simpler and less detailed than the tome I wrote and lost yesterday, but hopefully it will shed some light.

Originally posted 9/11/2019
Lamar has the only true linear string movement changer that I know of and it is linear raising and lowering.

The Anapeg changer uses the same dual pivot/virtual pivot concept that is found on Excel and new Sierra steels. The earliest use of this concept that I know of is found on some Rickenbacker pedal steels, the next in line is the brilliant, but ultimately ill fated Fender PS210 steels designed by Gene fields.

All are executed differently, but use the same concept. And none have truly linear string movement in either direction. The raises use a single pivot with a much larger pulling radius than that found on changers of any other type (except Lamar's). The lowers utilize both pivots to, in essence create a third and virtual pivot which again has a much larger pull radius (very nearly straight/linear but not quite). All this adds up to a less stressful life for the strings.

The virtual pivot idea is used in many industries utilizing motion and motion control. It came into my world when it began being used in bicycle suspension designs to counteract the pedaling forces that in many cases hampered the function of the suspension.

[John Hyland]

That great info Ross and I think I understand the mechanics now.

Apart from string breakage do you think there are other advantages over the typical changer style with a large axle? I assume there is very little lateral deflection and less friction plus you can remove a single changer for repairs and maintenance.

My challenge would be to print it in 3D as everything is a lot tighter than my solution for the "standard" changer
John

[Ron Pruter]

I really don't understand the picture, but could/would this be a for-shadow of an advancement that would allow for individual intonation adjustment? Ron

[John Hyland]

I really don't understand the picture, but could/would this be a for-shadow of an advancement that would allow for individual intonation adjustment? Ron

It took me a while to understand what I think is happening. But intonation adjustments are not really an issue for pedal steels and the rod you see is for the top pivot of the changer.

[Ron Pruter]

John, I beg to differ with you. As I go up th neck on my Emmons with new strings, the E strings, 4 and 8th string go out of tune together. I'm away from my steel right now but lets say the 4th string goes flat to the 8th. Moving the witness point(contact point)of the 4th string on changer roller to the left(while seated) would make the 4th string go up faster as you move up the neck. Ron

[Ross Shafer]

It's the lack of a finite amount of string displacement/bending that makes intonation adjustment on steel guitars moot. Keep in mind on fretted instruments one pushes the string down to fretboard, a point that determines the amount of string flex/displacement to a finite amount. Not very feasible on a fretless slide instrument as the string bending/displacement changes with bar pressure.....very hard if not impossible to be consistent enough for fretted instrument style compensation at the bridge. Its a matter of simple mechanics.