I though I'd revisit the Pneumag idea after a 6 or 7 year break from it and try and have a go at coming up with an anti short stroking mod. I don't know if anyone still uses the Pneumag or even if anyone cares anymore but I thought I'd give it a go and post up my idea and results. So I have in fact come up with an idea for it and it's so simple I'm suprised no one has thought of it before!
Anyway, as of now it's only half done as I had to re-convert my stock retro valved Mag back to a Pneumag which took up a couple of hours of cleaning parts and reasembling and gassing airing it up to make sure it works pre-short stroking mod. As of now I'm almost out of air so I can't complete the 3rd part of the mod until my dive bottle is tested, hopefully I can get it tested in a week or 2.
So the mod is this.
1. A pair of opposing magnets on the MSV-2. (No suprise there!)
2. A second pair of opposing magnets fitted to the rear of the trigger shoe just under the trigger stop, and to the front part of the frame where the trigger stop hits, again just under the trigger stop. The trigger is then pushed forwards far more efficiently. What happens then is the MSV-2 is doing less work to push the trigger forwards. This will be critical to it's success assuming the 3rd part of the mod works as they have to work in unison!
3. Where the rod makes contact with the rear of the trigger, the rod is pushed upwards by a small amount, of course when you keep the trigger depressd the MSV-2 still lets air through as the rod is still being pushed back. What I propose is to drill a small indent or hole at the point where the rod is at it's highest point when it's being pushed by the trigger. The rod thenv drops into the indent or hole and the MSV-2 stops letting air through. The Mag valve then completes one cycle and won't cycle again until the trigger is released and the rod drops back down to it's rest position ready to be activated once again.
The reason(s) it won't or might not work.
1. There is a little bit of play before the MSV-2's lever activates the valve, that bit of play has to be dialled out. Maybe with another set screw drilled through the front of the frame. I don't think it will work properly until that has been done as there will be too much movement from the lever for it to be able to reset. I think it might get stuck in the indent/hole, so walking the trigger might be difficult without the play being dialled out. There also has to be a small gap between the rod and trigger to allow the rod to drop down correctly.
2. The rod gets stuck in the indent/hole and won't release correctly.
If anyone can offer up any opinions or advice it would be greatly appreciated.