CGW "Race Hammer" Peak

[zfields]

If you need a test dummy for the decocker hammer, let me know : )

[Gunnie 18]

Are the hammers available?.?

[schmeky]

Gunnie18,

Not yet.  This has been an exasperating endeavor.  I'm given time lines, but they have not been accurate.  I am still pushing for a spring release.

[Gunnie 18]

Sounds good?..  Your parts are worth waiting for?..  Thank you for your contributions to the CZ community for it is greatly appreciated?.!

[nonamehavei]

Gunnie18,

Not yet.  This has been an exasperating endeavor.  I'm given time lines, but they have not been accurate.  I am still pushing for a spring release.

Sorry your having a hard time, but I'm with Gunnie, your stuffs definately worth waiting for!

Sent from this thimgy using tapawhatzit

[viking499]

Yes they are worth waiting for.  Working on my next order from him right now.

[huskerlrrp]

Yes, thumbs up good customer service and increasing the potential of the CZ platform.

[schmeky]

Thanks guys.  I had a completed sample hammer but it wasn't perfect.  I can't help it, but I know what this hammer has to do, and if it's performance isn't stellar, it will have to wait until it is. 

[korny351]

That's looking great.  Can't wait 'til the decocker version will be available.  Any thoughts as to whether this will allow a lightened hammer spring using a Kadet kit? 

[Stuart]

Keep up the good work David!
you really have to exercise patience when working with maching shops.

good luck!

[Thor™]

Will be placing another order once this design is ready to ship David. Thanks!

[schmeky]

I appreciate the patience.  I have been exchanging e-mails with a well known CNC - EDM wire shop about the final specs on the Race hammer this weekend. 

We'll see.

[BrightSight]

This is my first post, other than the introductory hello message I posted on the New Members forum.

I am an electrical engineer, not a mechanical engineer or a gunsmith, so this could be a very na?ve question. The original post indicates that one benefit of this new CGW "Cajun Race Hammer" design is that it is "extra heavy for excellent primer ignition".

I believe (but I am not certain) that the kinetic energy of the hammer depends on the strength of the mainspring and not the mass of the hammer. That is, increasing the hammer weight without changing the mainspring should not increase the hammer's kinetic energy at the moment it strikes the firing pin. However, I am much more certain that the mass of the hammer does determine the efficiency with which kinetic energy is transferred from the hammer to the firing pin.

I understand that the CZ firing pin ignites the primer in a two step process: first the hammer transfers momentum and kinetic energy to the firing pin with a striking impulse; then the firing pin moves a short distance after contact with the hammer to strike the primer. I believe the primer ignition depends on the amount of kinetic energy (not momentum) that is transferred from the hammer to the firing pin. Because of the hardness of the hammer and firing pin materials, the striking of the firing pin by the hammer is well approximated as an elastic collision (both momentum and kinetic energy are conserved), which is explained in this high school physics educational video:

http://www.youtube.com/watch?v=HdjxMw9bumI

I understand that the mainspring contacting the hammer and the firing pin spring contacting the firing pin complicate the analysis a bit, but at the instant the hammer strikes the firing pin, the hammer and firing pin and their attached springs have "equivalent masses" that dictate the transfer of momentum and kinetic energy from the hammer to the firing pin.

For best primer ignition, all of the kinetic energy in the hammer should be transferred to the firing pin. This occurs only when the two equivalent masses are equal. If the hammer is too light or too heavy, the firing pin will not receive  all of the kinetic energy carried by the hammer.

So primer ignition will certainly benefit from the increased mass of the new CGW "Cajun Race Hammer" if the equivalent mass of the firing pin at the moment of impact is better matched to the mass of the new hammer than the hammer being replaced. That is, primer ignition will benefit if the equivalent mass of the firing pin is larger than the equivalent mass of the original hammer.

Is that the assumption underlying the new hammer design -- that the original CZ design exhibits inefficient kinetic energy transfer because the original hammer is too light?

Or is there another physical principle at work here that better explains the anticipated benefit of the new hammer design?

Cheers,

Blair

[schmeky]

Blair,

I base my rational for an increase in hammer weight on a couple of factors.  When I shot S&W revolvers years back (still have a few), the upper tier guns came equipped with Target Hammers (TH) and Target Triggers (TT).  The TH's were significantly heavier than the stock S&W hammers.  S&W also backed off the strain screw in the front of the grip frame that tensioned the flat hammer spring on guns that were fitted with the TH and TT.

CZ has employed a similiar method with the Shadow hammer, which is full width at .313"-.315", and packs about 15% more weight than a stock CZ hammer.

I have also found a method to measure the impact depth of a primer consistently using my dial indicator.  I have found a heavier hammer tends to increase the depth of the impact indention.  Lastly, I have a way to lighten my Race Hammer if anyone ever decides to speed up lock time.   As anyone knows, it's a lot easier to remove steel as opposed to adding it.

I don't have the formulas to back-up my rationale, it's based on my experience with firearms for the past 4 decades.  I could be wrong

[no51]

[mechanical engineer hat]
If I may present my highly scientific illustration:

From what I've seen of his hammer, the center of mass is effectively moved away from the center of rotation, thus increasing rotational inertia.

Let's assume that, for the ease of calculation, that the stock hammer and the race hammer weighs the same, with the only difference is in the hammer design.

It would be probably safe to assume that the difference between the rotational velocity of the factory and race hammer is negligible.

If you remember from your physics class that kinetic energy is half times the mass times the square of the velocity:
KE=1/2*m*v^2

Since this is a rotating system, let us substitute velocity (v) with (wl) where w is the angular velocity and l is the length

we get:
KE=1/2*m*l^2*w^2

Since we assumed that they both have the same mass and have the same rotational velocity, we can compare the factory hammer (lf) with the race hammer (lr) as such:
(lr)^2/(lf)^2

now let us assume that lf=1 and that the race hammer shifted the center of mass to 1.1 times the factory center of mass so we have an lr of 1.1
(1.1)^2/(1)^2
or
1.21/1
or 21% more kinetic energy

Now all of this is based on numbers pulled out of where I, and many politicians and statisticians  pull their numbers out of, but it illustrates what is at work.

In actuality, they won't have the same rotational velocity; but the race hammer, due to shifting the center of mass further out from the center of rotation has more overall rotational inertia. There may be a point where it's shifted so far out that or that it's too heavy that it causes it to have less rotational inertia; but at that point, it would be ridiculously heavy or ridiculously long.
[/mechanical engineer hat]