Link to Weatherby’s mod if anyone needs it.
https://www.airgunnation.com/topic/fx-crownimpact-regulator-mod-tutorial/
It describes reconfiguring the stack of Bellevilles (spring washers) from a series stack ()()()()() to using nested pairs in series (())(())((. That doubles the spring rate (makes it harder to compress) but halves the available travel. The former is a good thing if the original stack was getting squeezed flat from adjusting to a pressure that is too high for them. The latter can negatively affect repeatability/consistency but with the relatively large number of washers in the regulator, it should not be a problem and indeed does not seem to have surfaced for those who have made the change.
Another change was adding a flat washer to prevent the acetal (plastic) piece from being damaged.
BTW, toward the end of the thread someone noted taking theirs apart to do the mod but it already had been set that way from the factory. He said it was creeping 10 bar anyway, but that he lubricated everything well and reassembled and it came down to 2-3 bar. So that may be something else to be mindful of.
I kinda skimmed the thread but it looked like it was hit or miss as to whether the mod fixed the creep on some rifles. That is not surprising to me because the most common cause in my experience is some sort of imperfection in the valve seat. Could be a tiny scratch from a piece of grit zipping through the valve seat, from long term wear of having cycled many thousands of times, or from the surfaces being misaligned/out of square (more of an issue with large apertures on some regs). Also, note that a brand new regulator will often creep until it has been cycled perhaps as much as a few hundred times so it’s a good idea to first give it a break-in period before pursuing other remedies.
FWIW, I have never experienced creep from having the setpoint adjusted too high. I had briefly looked for a spring rate curve to see if the force climbs significantly as they near full compression but didn’t find anything definitive. Based on the geometry, I would expect the opposite but it may be counterintuitive...to my way of thinking, anyway
https://www.airgunnation.com/topic/fx-crownimpact-regulator-mod-tutorial/
It describes reconfiguring the stack of Bellevilles (spring washers) from a series stack ()()()()() to using nested pairs in series (())(())((. That doubles the spring rate (makes it harder to compress) but halves the available travel. The former is a good thing if the original stack was getting squeezed flat from adjusting to a pressure that is too high for them. The latter can negatively affect repeatability/consistency but with the relatively large number of washers in the regulator, it should not be a problem and indeed does not seem to have surfaced for those who have made the change.
Another change was adding a flat washer to prevent the acetal (plastic) piece from being damaged.
BTW, toward the end of the thread someone noted taking theirs apart to do the mod but it already had been set that way from the factory. He said it was creeping 10 bar anyway, but that he lubricated everything well and reassembled and it came down to 2-3 bar. So that may be something else to be mindful of.
I kinda skimmed the thread but it looked like it was hit or miss as to whether the mod fixed the creep on some rifles. That is not surprising to me because the most common cause in my experience is some sort of imperfection in the valve seat. Could be a tiny scratch from a piece of grit zipping through the valve seat, from long term wear of having cycled many thousands of times, or from the surfaces being misaligned/out of square (more of an issue with large apertures on some regs). Also, note that a brand new regulator will often creep until it has been cycled perhaps as much as a few hundred times so it’s a good idea to first give it a break-in period before pursuing other remedies.
FWIW, I have never experienced creep from having the setpoint adjusted too high. I had briefly looked for a spring rate curve to see if the force climbs significantly as they near full compression but didn’t find anything definitive. Based on the geometry, I would expect the opposite but it may be counterintuitive...to my way of thinking, anyway
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