jamesp

 

Absolutely,  you will just need to devise a mounting method allowing a longer throw on the finger-end of your lever.

...as well as a double lever arm setup as a single (see saw) lever would pull instead of push.  I'm still trying to work that out in my brain.  Flexibility and space availability are pointing me in the direction of a qev.

I was wondering if some sort of lever type system might work to decrease the effort required or magnify the trigger pressure applied.  It seems I'm getting away from the original intent of building a very simple gun.  I just can't figure out how anyone else has made this work easily, not to mention how they have gotten repeated shots out of the tank without re-pumping.

I get all that, what is throwing me is that other people have built them using these kinds of valve without trouble. Wait, have you - Youre in my region? If its a regional thing, maybe *all* the valves locally available are too large internally?

I hate to shoot holes in your theory, but I'm in FL so probably not a regional thing.

Actually, color me curious to the answer as well. I built a Mad Ghost or the free version of the JSPB or something, none of my flow valves (bought several kinds trying to figure it out) would pop when pushed, not easily enough to act as a trigger anyway. I didn't have a gauge on them, but I only filled with enough pressure to seal the valve.

Thank you for verifying my concern

 

 

Well, think about it this way:  The force required to open your valve is calculated like this:

Force = (Pressure * Area of valve face) + valve return spring force

 

In the case that it were actually a 1/2" diameter valve with a 1 pound spring (1-2 is common), that would be an absolute minimum of: (0.25")^2 * pi * 20PSI + 1 pound = 4.93 pounds.

 

In reality, most 1/2" check valves have a diameter of about 3/4" to 7/8", depending on the quality, making the range of more like 9-14 pounds on the low end, or 14-20 pounds on the top end.  That's not exactly an easy pull, but you can see how it varies wildly.

That definitely makes sense, and although I didn't have the formula for it, in my analytical mind I figured the trigger pressure would be proportional to the chamber pressure as one would need to overcome the other.  So the question really is; is this how this particular trigger setup is intended to function or is there a method to get an easier trigger pull (larger valve, maybe?)

Actually, color me curious to the answer as well. I built a Mad Ghost or the free version of the JSPB or something, none of my flow valves (bought several kinds trying to figure it out) would pop when pushed, not easily enough to act as a trigger anyway. I didn't have a gauge on them, but I only filled with enough pressure to seal the valve.

Thank you for verifying my concern

The only slight modification I did was capped the 1" L prior to connecting to the check and I drilled a 1/16" hole in the cap as was suggested in another write up on the same assembly.  I am guessing that could be the cause of too little pressure to the barrel, but I can't imagine that would be the reason for the increased trigger pressure needed to release the valve.  As a side note, using the trigger mechanism with the backside of the checkvalve disconnected, I can blow in and release the trigger pretty easily.  even when I push the trigger enough to fire, the stefan doesn't go far at all.  like 15 feet.  I'm sure someone is going to ask for photos, so I need to get a photobucket account and take some pics.