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Topic: Mechanics 101 |
Stephen Williams
From:
from Wales now in Berkeley,Ca, USA
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Posted 21 Nov 2015 12:09 pm |
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Engineers and Artistes encouraged to join in!
Re Fingers: They have a downward force and a horizontal force applied to them through the string tension. It pushes the finger down and rotates it so bottom of finger goes to right. Ok so there has to be some friction from the downward force even if the finger is on a shaft.
To eliminate the friction part I could:
a)insert a ball bearing on the shaft or
b) have a fixed bridge like on a guitar to take care of downward force and run string to a finger behind the bridge and then the force on the finger would only be horizontal (actually the finger top has to be a tiny bit below bridge) so a little downward force is applied to finger.
On my first build attempt I tried option b) but i had Aluminium roller bridge and C-channel aluminium fingers.......it did not sound as good as a regular finger-as-bridge system so I changed it to a regular design, but it was prob because of the Al materials I had. Again, not sure. Does an early Fender 400 )which had roller bridge) sound any different than a later fender 400 with regular fingers?
For option a) If instead of a ball bearing I used a collar shaft we would have I would think less friction but I'm not sure or even if anything is gained.
Is anything gained at all? Or is the friction elimination better addressed at the cross rods/bell cranks.
When i get time i might run some tests to see what difference it makes........
This is all for my home-made PSG which I'm going to rebuild. This is the homebrew, the one that, that, legs akimbo, got sandwiched in the bus doors. ha ha. At least if they cough up what i asked for! |
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Ian Rae
From:
Redditch, England
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Posted 21 Nov 2015 3:19 pm
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Where there are moving parts, there is friction, which is a precise function of the coefficient of friction between the materials involved and the forces acting on them. It cannot be eliminated, but it can be minimised by choosing the materials well and lubricating them effectively.
This is not just my humble opinion and your mileage will not vary. (The properties of different alloys and the virtues of this and that lube have been discussed on here more than once.)
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Tim Russell
From:
Pennsylvania, USA
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Posted 21 Nov 2015 3:32 pm
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If I were going to design/build my own psg (which I plan to do at some point) I believe I would design the changer as a "Straight pull changer", such as the Lamar steel guitar (and others) design.
The design is beautiful, very efficient and I was impressed the first time I saw it.
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Sierra Crown D-10 |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 21 Nov 2015 5:06 pm Don't fix it if it ain't broke
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Unless a player has some serious physical disability or weakness, I don't really see friction as a "problem" in any modern pedal steel. Most pedal steels operate easily enough, even if they don't have helper springs, and wear (if the steel is lubricated every year or so) is so minimal that most guitars can go 20-30 years without a teardown or major part replacement.
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| On my first build attempt I tried option b) but i had Aluminium roller bridge and C-channel aluminium fingers.......it did not sound as good as a regular finger-as-bridge system so I changed it to a regular design, but it was prob because of the Al materials I had. Again, not sure. Does an early Fender 400 )which had roller bridge) sound any different than a later fender 400 with regular fingers? |
It's a moot point. For one thing, the Fenders didn't use aluminum fingers, they were steel. And for another, they made other changes when they changed the bridge design, so we don't know for sure if it was the bridge, or the other changes, that caused the majority of the resultant sound changes. But it's sorta standard knowledge that any physical change in the guitar design may change the tone.
If I were you (and I really mean this in a helpful way), I'd take the money you're going to get (for your old damaged guitar) and put it towards a new or used pro guitar.  |
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Ian Rae
From:
Redditch, England
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Posted 22 Nov 2015 1:58 am
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I learned to play a little on an old pro guitar before I built my own. That way I could tell if what I'd made was working as it should. I tried many years ago to build a PSG never having seen (much less played) a real one, and I got nowhere.
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Stephen Williams
From:
from Wales now in Berkeley,Ca, USA
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Posted 22 Nov 2015 12:55 pm
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Yes i am going to get an encore. But I am an opinionated sort (ha ha) ....er i mean discriminating sort, and i just have to finish building my own. I was actually quite happy with the one I built.
It had it's own sound but i do like the "chime" of others i hear.
I suppose PSG is very akin to Steam engines in being a perfect marriage of art and Engineering.
Onward, thanks for the response. |
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