FX Impact regulator whacky behavior

[rfuss928]

Just about every regulator I’ve used has a proportionality to it when it comes to fill pressures. This is the exact reason FX went to the double regulators in their Maverick . Regulators operate by spring tension , just like your car/truck . You wouldn’t expect the ride to be the same in you vehicle if you had it loaded to the hilt in comparison to being in it by yourself. The same applies to your regulator . I have found that using a 100 bar window between filling keeps the regulator working optimally . I see this topic come up often enough between just about every forum I visit , nobody seems to be buying into my conspiracy theory.

Ok I'll buy the 'window' theory.

I was involved in the design and testing of regulators. The change in output pressure vs input pressure was referred to as gain - zero is ideal. Virtually all regulators exhibit a positive gain with the output increasing some proportion with increasing input pressure. It is generally a function of the inlet seat (sealing) diameter and the spring rate. On my well tuned guns this shows as a slight decline in fps (<10) from max fill to nearly reg set point.

 

[avaris]

Finally I sorted out what is happening to MY impact mk2. There is not exactly a decrease in reg pressure actually as the air pressure falls below 150 bar. It is a very slow recovery of the reg especially from 120 b to 130b where it is set.It is so slow that you can miss it. I noticed that everything is ok from 230 bar to 200, at that range the reg has a fast recovery time. From 200 to 180 bar the reg pressure returns instantly to 120 bar after each shot, but it takes almost 60 seconds then to reach the set pressure of 130 bar. As the air pressure drops from 180 to 150 bar the recovery time from 120 to 130 increases gradually to more than 180 seconds. Below 150 bar the reg of MY impact returns instantly to 115 bar and takes ages to reach 130 bar.

Unfortunately I didn't have time to chrono the shotstring, which I plan to do next time. 

 

[Vetmx]

FX told me to go ahead and take it apart. I haven’t yet but I will pay attention to mine and it’s recovery time once I’m below 150b. Thanks for the update. If mine acts like yours, I know what I need to do once I get my reg apart. If that doesn’t work I will try a Huma. I’m headed out on a hunting trip now so it will be a while before I get back to messing with the gun. Avaris, I will let you know what I come up with. Thanks again.