Theoben Rapid Forum
Everything Technical About Rapid => Technical => Topic started by: angrybear on October 02, 2021, 03:32:00 PM
Playing with the .20 MFR I noticed the ME was a little low at 11.15fpe (663fps with FTT's) hammer adjuster was all the way in so thought I'd give the reg 1/2 a turn more, to up it a fraction.
The book (download) says turn nut clockwise to increase so I gave the nut 1/2 a turn clockwise & it dropped to 5fpe (445fps) ???
So reset the nut as it was & gave it another 1/4 turn back anti clockwise, 11.72fpe (680fps) Perfect 8)
but a tad confusing as that's the opposite to what should have happened ???
Well with the standard valve-stem style.
bottom valve in photo...
(https://photos.imageevent.com/scl_electronics/gun/air/websize/valve_1_.jpg)
It is possible that the hammer pushing the valve-stem so far that the nonreduced stem area is restricting the flow...
So reducing the spring tension a little, is allowing better air flow!!
So This will give you a Bell Curve effect as you adjust the hammer tension!!!
Just like Fill pressure!
Stuart
That is what should have happened. If you increase reg pressure but keep the same hammer spring tension, then valve opens less. If you drop reg pressure slightly, then valve opens longer. Reg pressure has to be matched with spring tension.