stryker spring question
Posted 17 December 2008 - 08:38 PM
Posted 17 December 2008 - 08:43 PM
my bet is with a spyder type gun, they tune it pretty well when they designed it, so they are probably as close as you can hope for.
the only issue and why spring tuning becomes and issue is when you use a gun for something other then it was designed for, like taking an autococker and pumping it.
And yes, Gordon is the sexiest manifestation of "to the front."
Posted 18 December 2008 - 09:55 AM
(for those that don't know, sweet spotting a poppet valve means turning UP you HPR pressure until the velocity goes down, because the force on the valve face is causing the dwell to be short enough that the overall energy flow through the valve is lessened.)
The other forces involved are the weight of the striker (weight holds the system open longer - it's a damping force, and also increases the assembly KE. In many pneumatic guns the KE effect is more pronounced since the maximum assembly velocity is fixed by porting). The very best blowback efficiency is generally sweet spotted HPR, with a tuned DOWN blowback jet, and a weaker spring. The trick is getting the weight and spring tension down, but not so low you can't get velocity.
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Posted 03 January 2009 - 01:55 PM
If you lower your input pressure, the spring balance required for sweet spotting changes too. One thing to consider is that very stiff springs cause things to slam around harder, which may wear out your sear and hammer more quickly.
The accepted wisdom from people like Moody Paintball is that the sweet spot is the most efficient, and just a few psi lower is most consistent (without losing much efficiency). I have always set up my guns this way with very good results.
It seems to me that this might make a good test. I have a bunch of reballs and an xradar handheld chrono. (way nicer than the little yellow triangle) If I can ever find a reball insert, maybe I can sweet spot a spyder clone and a cocker, fill two identical tanks to the same level, shoot the tank empty at sweetspot, and then dial the reg back about 10 psi put on the other tank,rinse and repeat. Compare the difference in shots and see what I find. I doubt my chrony is accurate enough to make people happy about consistancy comparisons, but you cant argue too much with with shot count for efficiency. How many shots over the chrony are necessary to get meaningful data for consistency comparisons?
Another llong held assumption is or was that guns are less efficient at high ROF. That makes sense to me for CO2, but it seems like high rof guns that suffer from shoot down should be using less gas per shot as the regulator lags, so it would be cool if someone could test that.
I don't really want to mess with comparing efficiency at different rof's right now. I think the way I would do it would be to try and always shoot at the same rof. with the spyder clone I would put it on 6shot burst and tally each time I pulled the trigger until the tank is empty. With the autococker, I would probably just put it on PSP zero the shot counter, and keep it going untill the hopper gets low, topp off the hopper and keep going until I run out of gas.
Edited by Merc4Hire, 03 January 2009 - 02:34 PM.
Posted 08 January 2009 - 08:36 PM
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