OP
Hannibal Barca
Member
Thanks a lot for the explanation.
Main coil spring vs leaf spring
- Thread starter Hannibal Barca
- Start date
OLDSTER
Member
springs
Some of us old trap shooters have debated this for years
Even in "high-end" competition shot-guns, you'll see both kinds. As an example, Ljutic and Krieghoff use coil springs, while Perazzi uses leaf, and Beretta uses coil in some and leaf in others. The best explanation I've heard is it depends on the geometry of the design ( as in side lock vs box lock--but then Perazzi is a box lock-go figure ), as in the difference in a S&W vs Ruger revolver ?
Some of us old trap shooters have debated this for years
Even in "high-end" competition shot-guns, you'll see both kinds. As an example, Ljutic and Krieghoff use coil springs, while Perazzi uses leaf, and Beretta uses coil in some and leaf in others. The best explanation I've heard is it depends on the geometry of the design ( as in side lock vs box lock--but then Perazzi is a box lock-go figure ), as in the difference in a S&W vs Ruger revolver ?
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The definition of the word "Tampax" is what was asked for and we may be embarrassed to say exactly what it is.
"Tampax" is the brand name for feminine-hygiene products used during menstruation. I think "tampon" is the more generic name for the product.
With that in mind, look at the location of the white material inside the spring coils (on the link) and you'll see the analogy.
Enough biology, I'm an engineer, and I'll stick to that from now on.
As OKFC05 said, the material inside the spring is called a "damper" and does absorb (and then dissipate) energy. Dampers of various sorts are essential parts of a properly-designed dynamic system.
Designing for proper dynamic behavior of any system is both interesting and challenging. As OKFC05 says, "there are all sorts of really oddball failures due to transients and harmonics."
Perhaps the most famous of those is the failure of the Tacoma Narrows Bridge in 1940.
[ame]https://www.youtube.com/watch?v=j-zczJXSxnw[/ame]
Watch the Youtube video and you can see that the wind isn't strong enough to blow a guy's hat off, but it's enough to cause the bridge to fail catastrophically. (This is due to a phenomenon known as "vortex shedding" at the structure's resonant frequency. This is due to the interactions of both fluid dynamics and structural dynamics, but it illustrates the importance of considering the dynamic issues in designing anything, including firearms, which is the topic of interest.)
These questions/issues are mid- to upper- level mechanical engineering topics (with some grad school thrown in).
It's the weekend, so class will resume on Monday, for those interested in looking at some of the details involved in these matters.
(OKCF05 feel free to join in, since you also have had practical experience in this stuff...)
"Tampax" is the brand name for feminine-hygiene products used during menstruation. I think "tampon" is the more generic name for the product.
With that in mind, look at the location of the white material inside the spring coils (on the link) and you'll see the analogy.
Enough biology, I'm an engineer, and I'll stick to that from now on.
As OKFC05 said, the material inside the spring is called a "damper" and does absorb (and then dissipate) energy. Dampers of various sorts are essential parts of a properly-designed dynamic system.
Designing for proper dynamic behavior of any system is both interesting and challenging. As OKFC05 says, "there are all sorts of really oddball failures due to transients and harmonics."
Perhaps the most famous of those is the failure of the Tacoma Narrows Bridge in 1940.
[ame]https://www.youtube.com/watch?v=j-zczJXSxnw[/ame]
Watch the Youtube video and you can see that the wind isn't strong enough to blow a guy's hat off, but it's enough to cause the bridge to fail catastrophically. (This is due to a phenomenon known as "vortex shedding" at the structure's resonant frequency. This is due to the interactions of both fluid dynamics and structural dynamics, but it illustrates the importance of considering the dynamic issues in designing anything, including firearms, which is the topic of interest.)
These questions/issues are mid- to upper- level mechanical engineering topics (with some grad school thrown in).
It's the weekend, so class will resume on Monday, for those interested in looking at some of the details involved in these matters.
(OKCF05 feel free to join in, since you also have had practical experience in this stuff...)
I have found many leaf springs weak and taking on the arch that the preload has set upon it through the years - let alone the continual working of the action on a shooter.
I have also found MANY J frame guns exhibiting "coil bind" due to too long of a coil spring. This causes the last bit of hammer pull to be extremely difficult as you are "crushing" the coils together. That seems to be an engineering problem. I have fixed many by simply cutting the coil a bit shorter.
There is no doubt that the leaf spring provides the smoother action.
Who has ever bragged about the incredible smooth action on their J frame?
I have also found MANY J frame guns exhibiting "coil bind" due to too long of a coil spring. This causes the last bit of hammer pull to be extremely difficult as you are "crushing" the coils together. That seems to be an engineering problem. I have fixed many by simply cutting the coil a bit shorter.
There is no doubt that the leaf spring provides the smoother action.
Who has ever bragged about the incredible smooth action on their J frame?
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OP
Hannibal Barca
Member
I never had tried an old I frame with a leaf main spring, how good (or how bad) was the action of those olds I frames?
Once somebody told me the J frames needs a heavier main spring because the hammer of the J frames are lighter and needs that strength to ensure the firing pin hits the primer with enough authority to detonate it.
Beside the hammer are light, the J frames has less leaver effect due its small size parts. And that is another reason because it needs a heavier main spring.
Forgive my bad English.
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Jim Watson
Member
There is at least one PPC gunsmith, Travis Strahan, who will put a coil spring in a K or L frame. A friend likes his.
MY Perazzi MT6 had coil springs, although in the minority for that make. Sorry I sold it.
It is not a boxlock in the usual Anson and Deely sense; it is a trigger plate action akin to Dickson, MacNaughton, and Brown "round actions" and the German Blitz, but rendered quick detachable.
MY Perazzi MT6 had coil springs, although in the minority for that make. Sorry I sold it.
It is not a boxlock in the usual Anson and Deely sense; it is a trigger plate action akin to Dickson, MacNaughton, and Brown "round actions" and the German Blitz, but rendered quick detachable.
Green Frog
Member
Señor Barca, there is nothing to forgive about your English... it is better than much of what is posted here regularly. Sorry I can't find the proper letter n on my keyboard to write "señor!" Oops, there it is!
As for your question about the original I-frame guns with leaf mainsprings like their larger siblings, I find them to be smoother than the later coil spring guns; it's difficult to describe and it may be somewhat imagined on my part, but I definitely think it is there. I'm not sure that the reduction in size changes the geometry of the hammer sufficiently to produce the difficulties with ignition you mention, and to be honest I've never had a misfire with any of my several I-frame guns that could be blamed on that factor.
Of course another thing to consider is that all of the I-frame guns were made at least 60 years ago and most have been "worn in" to the point of being smooth, but I just don't think a well worn J-frame comes to the same level of trigger pull (even though I have a Baby Chief that comes pretty close!) I've even considered converting a Model 36 to leaf spring, but "considered" is as far as I have gotten.
That's my personal and probably biased opinion on the subject, or as we say around here, "That's my story and I'm sticking to it!"
Froggie
OP
Hannibal Barca
Member
Mr. Green Frog, thanks a lot for sharing your experience. I had always wondering how was the trigger feeling of those I frames with leaf main spring.
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OP
Hannibal Barca
Member
Maybe the reason that some people (me included) tends to believe that the coil main spring is stronger is for the the Single Action Army 1873 type case, The Colt Single Actions Army has leaf main spring and the Rugers Single Actions has coil main springs, and the colt mains springs broke more often than Rugers.
Maybe in the double action K, L and N frames are different.
Maybe in the double action K, L and N frames are different.
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Green Frog
Member
It is pretty widely accepted that a coil spring is more durable than a leaf spring, but that is not what my main concern would be... I want the trigger pull to be great while still having the ability to set off primers dependably. If I have to change out a leaf spring from time to time, so be it, but so far none has ever broken. Other folks' mileage may vary. At this point I haven't been able to bring myself to convert a Model 60 to a leaf spring, but I haven't totally abandoned the idea either.
Froggie
Froggie
