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PostPosted: Sun Feb 23, 2014 11:22 pm 
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http://www.network54.com/Forum/79537/me ... ct+striker


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PostPosted: Sun Feb 23, 2014 11:32 pm 
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:rolleyes:


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PostPosted: Mon Feb 24, 2014 4:46 am 
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I'd love to see that explained for dummies. I'm fairly sure my Brocock Atomic is wasting significant air volume owing to am inefficient striker/valve setup. I've tweaked it in a few ways including adding a bit of mass (improved velocity consistency) and testing hammer projections until finding the optimum length and cutting the spring a little, but this guy seems to have a deeper grasp of managing the valve. Anyone care to elaborate in layman's terms as to what he's done?


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PostPosted: Mon Feb 24, 2014 5:29 pm 
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GerardSamija wrote:
I'd love to see that explained for dummies. I'm fairly sure my Brocock Atomic is wasting significant air volume owing to am inefficient striker/valve setup. I've tweaked it in a few ways including adding a bit of mass (improved velocity consistency) and testing hammer projections until finding the optimum length and cutting the spring a little, but this guy seems to have a deeper grasp of managing the valve. Anyone care to elaborate in layman's terms as to what he's done?



We need physics professor Bob to dumb it down for us! :rolleyes:

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PostPosted: Mon Feb 24, 2014 7:25 pm 
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Neat idea. Two strikes, one delayed after the other by the time needed for the weak spring to accelerate the secondary mass. Not sure what the yellow circle and blue area marked HDD are, or why the secondary strike appears to only come into play when the working pressure is low. Calling Bob...


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PostPosted: Mon Feb 24, 2014 8:01 pm 
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HDD is hammer de-bounce device isn't it.

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PostPosted: Mon Feb 24, 2014 8:24 pm 
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Ace wrote:
HDD is hammer de-bounce device isn't it.


Yes...Back in the day Larry Durham came up with this idea. The theroy behind it IIRC, was to be able to use the accelerated mass to strike the high resevour pressure. Enabling the hammers force to become more consitant upon opening the valve as pressure decreases. Voltar maybe able to shed more light upon it. Believe he and LD had quite the discussion upon it.

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PostPosted: Mon Feb 24, 2014 10:12 pm 
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Steve is using an oscillating mass inside the striker to add to or subtract from the hammer momentum at various points in the shot string in an attempt to flatten it out.... When properly tuned it will probably work great.... change anything and I'm guessing you will have to retune the resonant frequency of the weight inside the striker....

Bob

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PostPosted: Mon Feb 24, 2014 10:42 pm 
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Yeah, ain't it the harsh truth. I did a bunch of fine tuning with hammer mass and length, spring cutting, spring pre-load and port size on my Brocock Atomic until I had it in the flattest velocity curve I could manage; about a 20fps high and low which seemed tolerable enough considering the tiny cylinder size on the thing. Then recently I switched from 14gr pellets to 15.8gr, and testing today I find that the curve isn't a curve at all, it's the Rocky Mountains! So I just spent 2 hours playing with various pre-load tubular shim lengths behind the spring and finally clipped another turn off the spring and put in the longest shim yet (8mm - it just barely cocks but it works) and presto, back to an almost flat line. Glad I've settled on JSB Jumbo Exacts as being very happy with this gun, as I don't want to tackle tuning it again for a long while.

Seems to me likely that with a tiny reservoir like my pistol has there'd be little if any point in this mod anyway. When my MV starts dropping significantly there are only about 2 or 3 shots left anyway before it hits 50bar and won't shoot worth a darn. There's no more air to boost with hammer spring and weight tricks. But I can see, I guess, what they're talking about with larger cylinders and higher pressures.


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PostPosted: Mon Feb 24, 2014 10:44 pm 
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That's an interesting concept. I was confused until you mentioned that the inside cylinder mass is oscillating and hammer that absorbs the shock from hitting the stem..

My guess is that instead of a quick hit to the valve stem, it might end up being a softer hit with a longer duration. As the pressure in the valve decreases towards the latter part of the shot string, the inside cylinder will react less too the stem pushing back, allowing more air to be released.

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PostPosted: Mon Feb 24, 2014 11:50 pm 
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:rolleyes:


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PostPosted: Tue Feb 25, 2014 12:15 am 
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Edmonton<500 wrote:
:rolleyes:


Imagine a button on the hammer face that depresses to soften the impact of the hammer on the valve stem.

In a normal hammer, the surface is solid and would hit the stem with full force.


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PostPosted: Tue Feb 25, 2014 1:14 am 
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cool drawing Tony!
I think Daystate has a video of one in super slo-mo!

Its a "Slingshot" system!
[img]/http://daystate.com/huntsman.htm[/img]

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