Paintball

[splattttttt]

Originally Posted by capitalpaintball

that's the back of the piston. the head has the middle sized o-ring. I tried to add another o-ring but it didn't fit right.

I know. Is it possible that may be where the air is coming through during recock?

[capitalpaintball]

no, the back o-ring moves the piston back and forth, the one closest to the head seals the incoming regulated air when the gun is fired, and the piston head o-ring seals the dump chamber until its fired.
when you cock the gun the hammer is lifted off the clippard valve,(that's the chuff you hear) moving the piston forward allowing the o-ring closet to the head to slide out of the body, thus filling the dump chamber, at the same moment the piston head o-ring seats in the front hole, plugging the dump chamber. it needs to get there a fraction faster to seal it before the air escapes.

[commandoman]

You know, I would not be surprised if Metadyne was reading this thread trying to figure the problem out lol

[Rage 01]

They would be a fool not to. A great place to get information. There are more people watching and inputting information in this thread than there is in Idaho.

[toymachine]

lol but then again mcb isn't the potato capitol of the country

[LilShank]

Technically our main export is lentils

I know that they've had a presence here, no idea if they do now, as the most recent person from Metadyne to have an MCB account no longer works there, and I haven't seen nor heard from Scott since the beginning.

I've been meaning to offer a bar of SS to Brain for testing but I'm not sure he would be down for it

[toymachine]

Yea, sadly it seems that he's just not interested in the extra cost/tooling involved in getting a ss piston made. Wish it were otherwise though, have since all this started

[toymachine]

Originally Posted by capitalpaintball

no, the back o-ring moves the piston back and forth, the one closest to the head seals the incoming regulated air when the gun is fired, and the piston head o-ring seals the dump chamber until its fired.
when you cock the gun the hammer is lifted off the clippard valve,(that's the chuff you hear) moving the piston forward allowing the o-ring closet to the head to slide out of the body, thus filling the dump chamber, at the same moment the piston head o-ring seats in the front hole, plugging the dump chamber. it needs to get there a fraction faster to seal it before the air escapes.

srry for the double post, but this is very cool - I just learning something new, specifically about the source of the chuffing sound when cocking the gun I couldn't previously explain. Now it makes perfect sense. So, if I understand it correctly, that chuff is from air the escaping that had been diverted by the actuating valve to move the piston backwards to open the dump/front chamber when the gun is fired? In that sense, it's like a qev, no?

I always worried about losing efficiency when I heard that sound, but it would seem that's it's not some leak but the exhaust from the piston's rear most section? In which case it's not a big deal in terms of efficiency???

thanks again capital!! you've made some great contribution to our little cult here

[woouulf]

I always thought the o-ring channels were too wide on the piston shaft, i just couldn't see a need for them to be like that and for the life of me i just dont understand it ..I still want to have a piston made of SS and the chanels a lil smaller..On another note, my thumper went down last weekend. I had the reg set to 275-280 psi output and 5 or 6 shots and poof and that was the end of the that..I hope it was a rolled o-ring and not a bent piston since i have only one left..

[woouulf]

Humm, Is it possible that i have a SS piston or is it just steel ? I just took one of my thumpers apart and and although ive had all verison of pistons, this one looks ood..Pic's are big for a reason.
It seems to be a V1 piston and the reason it was replaced by the V2 was the heads always came loose as this one did..I remember having this type , just not this material..