Physics question

ColinMmmmm · #1 12-09-2007, 11:50 AM

So I've got a question - you've got one trem set up with 3 springs, then 4, and 5 - with the same tuning, total spring tension etc. - when you use the trem, would the one with 5 springs be harder to use than the one with three springs. I was thinking about it for a bit, and was like

"hmmm, well you could set them so the tension at one specific point was equal (when the spring tension equals the string tension), but if you pulled them the same distance with the trem, the 3 springs might be easier to stretch than 5"

Think about it . . .

CityofBlindingLights · #2 12-09-2007, 01:52 PM

Yes, but wouldn't five springs have better tuning stability? And my guess is there'd be better tonal transfer...

I myself am partial to three springs though because I don't like having to push down too hard on my trems. Then again, I'm not a Floyd user.

And by the way I'm pretty sure this isn't as much physics as it is common sense... unless you'd like to go in to torques (force x distance)... sorry I'm a total physics nerd

Jaden · #3 12-09-2007, 02:55 PM

no, its mechanics also - the springs have an individual linear or non-linear response so...
if you use 3 springs and strech them to equal the spring tension they will be streched a lot more toward thier fullscale deflection than the equivalent 5 spring setup changing the feel of the response to futher stereching completely.
the springs response curve will dictate how the trem will feel dependant on how many and the configuration - stright or vee.

ColinMmmmm · #4 12-09-2007, 03:03 PM

Yup - thats what I'm wondering. Exactly. Because the force needed to stretch a spring changes depending on how stretched it is already. But it's sort of a complicated problem. I wonder why more people don't try 4 or 5 springs? Maybe they all just use the whammy bar so much they like it to be easy.

Eggy · #5 12-09-2007, 03:11 PM

Fit 3 springs in the back, 1 up the middle and the outside ones in diagonal formation and stop worrying about physics and mechanics.

ColinMmmmm · #6 12-09-2007, 03:21 PM

I've got 4 in the back. I'm running a set of 10-52's (and loving them). I'm just wondering how changes in the springs affects the feel and tuning stability of the trem.

Jaden · #7 12-09-2007, 03:54 PM

Ben's right but....
if you really want to know then you have to know the response of your springs mechanically..

otherwise just go with what feels good - what feels good to me personally is 3 new springs in a vee...

David McCarroll · #8 12-09-2007, 06:08 PM

From memory, a spring takes the most force to initially "open" it from its rest position - the more springs you have in a trem, the less tension on each spring so the closer to its rest position, hence I would expect that more springs = stiffer feeling trem. As someone pointed out, this is probably the position at which a spring displays its most non-linear behavior, hence less probability of the trem returning correctly to its centered position.

Of course, I could also be totally wrong........

bakerman · #9 12-09-2007, 08:17 PM

Steel springs should be very linear in response. http://en.wikipedia.org/wiki/Hooke%27s_law

I've measured the response of a spring (from a Floyd-equipped Carvin) by hanging weights from it:

at rest 52 mm
5 lbs. 60 mm
10 lbs. 68 mm
15 lbs. 76 mm
20 lbs. 84 mm

So for any springs that act that way, more springs will be stiffer and more reliable for perfect 0 return.

Since the arrow arrangement is another common topic, I'll mention that 3 springs in an arrow should result in less stiffness than 3 straight springs, but it's by a very small amount with typical springs & trem block. When you take into account the way the spring angle and length changes as you move the bridge, the angled springs don't change their actual pull on the block quite as much as a straight spring.

satchboogeyman · #10 12-09-2007, 10:29 PM

I have found that more than three springs sounds like it has a built in reverb tank in the guitar.

ColinMmmmm · #11 12-10-2007, 12:10 AM

Quote:

Originally Posted by bakerman

Steel springs should be very linear in response. http://en.wikipedia.org/wiki/Hooke%27s_law

So for any springs that act that way, more springs will be stiffer and more reliable for perfect 0 return.

See - thats what I was wondering. I just wasn't sure if the force to stretch a spring was linear. But it makes sense. Stiffer trem, better stability. Maybe I'll try it sometime.

jl2556 · #12 12-10-2007, 09:53 AM

Quote:

Originally Posted by satchboogeyman

I have found that more than three springs sounds like it has a built in reverb tank in the guitar.

To eliminate that you could do what Vai does and stuff some
padding in the spring cavity....

bammbamm · #13 12-10-2007, 10:43 AM

The other issue would be the trem angle would have to be accounted for, and countered by heavier strings. If you put 5 springs in the back, you're going to have MASSIVE pull. So yes, stiffer feel on the trem, but also a major adjustment on setup and angle.

Vim Fuego · #14 12-10-2007, 12:34 PM

Interestingly if you apply Hooke's Law then the stiffness of the trem is proportional to the number of springs, just as you'd expect.
However using 3 springs in an arrow shape although popular should have no effect on the feel (I suspect it does in reality). The slightly more stretched springs will mean that the centre spring will be less stretched so the effect cancels!
Unless the centre spring is so slack that it isn't doing anything until you push the trem arm down!
I believe Eddie Van Halen uses 3 springs, The treble and middle ones parallel and the bass one angled!
Jim

gpenguins · #15 12-10-2007, 01:44 PM

Quote:

Originally Posted by Vim Fuego

Interestingly if you apply Hooke's Law then the stiffness of the trem is proportional to the number of springs, just as you'd expect.
However using 3 springs in an arrow shape although popular should have no effect on the feel (I suspect it does in reality). The slightly more stretched springs will mean that the centre spring will be less stretched so the effect cancels!
Unless the centre spring is so slack that it isn't doing anything until you push the trem arm down!
I believe Eddie Van Halen uses 3 springs, The treble and middle ones parallel and the bass one angled!
Jim

I think the difference between parallel and angled outside springs is nominal at best. I have 3 springs in almost all my guitars, some are parallel, some are angled outside and there's virtually no difference - especially considering tension is further adjusted by moving the spring claw in or out.

Why the difference in guitars if there's essentially no difference? Simple - the ones in parallel were put in by someone who had small enough fingers to fit them on the 1st and 5th position on the claw, but my fingers being too fat, well, it's easier to just hook them into the 2nd and 4th hooks on the claw.