Stealth "power curve"....

[BuddyBoy]

So, prolly one for le Git here...

Am playing with a stealth or two at the mo...

Forget power, one will be going on ticket anyway, this is purely a question of consistency (over a no. of shots - shot-to-shot consistency is fine)

So, is it possible to achieve a power curve on a Stealth, i.e. gradually rising, levelling off, then falling, as opposed to a simple decline ?

Background...

Ally hammer, very nice, thanks Trev, shot-to-shot is within 10 fps (fine). Barrel either 12" or 18" - the "curve" is much the same, velocities are obviously higher with the longer barrel...

Am going to try reducing spring preload to achieve a curve, but is it worth it ?

Should I use the top hat adjustment (prolly with an O ring beneath it) to simply limit the valve's travel instead ? Trouble with this is you completely lose the "self regulating" aspect of most knock open type valves, whereby the higher air pressure restricts valve movement at the begining of the curve, with the oposite at the end, resulting in a similar (volumeXpressure) air blast each time...

I have played with various stem ports (butchered stem, filled with areldite, then progressively re-ported, and whilst tighter porting obvious chokes off the higher velocities, it really still isn't a true power curve - just a flat, then fall...

Whatdya reckon then guys ????

PS on the FAC one, only looking for around 25 FP, 18" barrel (this obviously isn't exactly hard in itself !)

Thanks in advance,

JB

[gary_cooper]

Gee Pa...you're so smart :-)

I just pulls the trigger..

[BuddyBoy]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by gary_c:
Gee Pa...you're so smart :-)

I just pulls the trigger..[/quote]

Yeah, and you need to work on that too... <img src="http://jsramsbottom.co.uk/bbs/e/icon_razz.gif" alt="Razz" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

[StephenJH]

How do I get an ally hammer!?

[naturalskinhead [TREV]]

Stephen, ALLOY HAMMERS ,Jon knows someone who gets them made <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

[L96A1Sniper]

I get 28 lb/ft with brass hammer and a tuned tophat,and 18" barrel,thats a FAC stem
moving the spacers around does not do much at all
more consistant with the brass hammer slide

i think thats about as good as it gets

more problems with any higher lb/ft i.e. leading barrel,falling to bits,and NOISE!!

all the other `tweeks` on the talon site,only have a marginal effect.

[leupy]

Can supply you a hammer Stephen, aluminium or brass, made to measure.
Mail me if interested.

[leupy]

Can supply you a hammer Stephen, aluminium or brass, made to measure.
Mail me if interested.
<img src="http://jsramsbottom.co.uk/bbs/e/icon_smile.gif" alt="Smile" width="15" height="15"><!--graemlin:-->

[leupy]

Oh shoyte......just posted a doubler.

Maybe one of each then. <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->

[BuddyBoy]

Hi Sniper, yeah , I can get plenty of power too <img src="http://jsramsbottom.co.uk/bbs/e/icon_razz.gif" alt="Razz" width="15" height="15"><!--graemlin:-->

really looking for a decent "flat" in the curve..

Otherwise I'll just resort to choking off via stem porting (that's all your FAC stem is anyways)

Cheers,

JB

[StephenJH]

Leupy....YHM (to your profile email address)

[BuddyBoy]

Just a bump for any old gits <img src="http://jsramsbottom.co.uk/bbs/e/icon_smile.gif" alt="Smile" width="15" height="15"><!--graemlin:-->

[linegeist]

<img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

I've been experimenting with 'O' rings of different rubber compounds between the Top Hat and Valve body to produce a tunable rebound shutoff effect.

So far the results have been very interesting - but complex to decipher. I'm now writing a computer program to collate the results..... In the meantime, balancing/controlling the opening/shutoff phases of this mechanism by introducing a closed loop servo effect appears to give a plottable power curve of sorts.

Meanwhile I have a headache! <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:--> <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

regards
BC

[This message was edited by Le Git en France on 30 July, 2003 at 19:54.]

[BuddyBoy]

Cheers Bob <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->,

figured it might be worth a play <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->

It looks like overly-reducing the spring preload to try to introduce a "rise" at the begining of the power curve just winds up messing up the whole thig anyway, and giving unnacepatbly low power... any thoughts ?

Thanks,

JB

(who's now got two stealths to play with - easier with low and high fill bottles for power curve stuff)

[leupy]

Bob,
Nothing to do with the thread (sorry)..(interesting stuff BTW), but just wondering if you saw my post re Gill at Kingswells.
An e-mail reply to my profile address would be appreciated.
Thanks.