Paintball

[splattttttt]

Originally Posted by capitalpaintball

So the o-ring popped out again in the store while dry firing. so I decided to super glue it in.
Played today with it, shot 100 rds at the chrony and played a game where I shot 200 rds and no leaks.



Only problem I noticed was some major inconsistency over the chrony and when shooting it you can hear the difference between shots.
turns out that sometimes when you cock it there is a puff of air the blows the ball past the detent causing the inconsistency.
need to find out why this is happening, maybe the piston head oring? or the spring. maybe the piston needs to be a fraction longer.

what about a spacer for the piston to help take up the slack?

[Morhaughn]

Has a stainless piston been tried? if someone knows if Brian did or did not try it let me know so I know if Iwould be waisting time making one.

[capitalpaintball]

So far as I can tell the new piston is the same length as the old one but the o-ring placement on the piston head is slightly lower.
My thought is that: the air filling the dump chamber is just escaping for a fraction of a second before the piston head seals the chamber.
I am going to try a spacer between the head and the shaft but I dont want to make the piston to long.
I have sent an e-mail to Brian to ask his advise.

Maybe reg spiking could also be a contributory factor?

I am running a secondary regulated co2 bottle at around 250-300 psi. its not the most consistent of regs, but it is working. it relieves the stress of the internal reg having to deal with high pressure. one of the ways the Thumper use to fail was the internal reg would lock forward. you would be shooting and all of a sudden nothing. so far the dual system is working well.

What if it was made of stainless steel?

It was tried and failed. well plain steel not stainless

[toymachine]

The piston would probably be better off had it been made from ss. I always wondered why they didn't go from al to ss, but I guess it just had to do with manufactoring/machining costs. There was once a rumor about a brass piston but tbh I never really understood that idea and in any case it never materialized. I think one of the main consensuses on why the pistons would snap (normally around the first oring groove from it's head) has been due to pressure spikes, given that adding an inline reg to prevent the inline reg from spiking over 300psi seems to have solved the piston problem for a number of people. But of course the piston might be snapping for other reasons I just don't understand(?).

If you want to avoid sending you thumper in for the newest piston upgrade (the thickest version that seems to actually work long term), get an inline reg for your thumper and change out all o-rings as you plan. Lube gun regularly and correctly. As you're getting a used thumper, make sure the actuating valve works if the previous user had problem with it (input limit is 300psi, not a problem with inline regs and for some lucky thumper owners where their internal thumper reg seems to have worked out fine).

Sorry that last sentence was a little jumbled lunchbreak's what it is

edit - sorry cp, I always forget you're already running it with a reg upstream of your thumper's input

[Rage 01]

Thankx for the info. I think as soon as it gets here, the new project on my lathe will be a ss piston. I will keep you posted on how that works.
I guess I better order a actuating valve as well just in case.
I will go threw the post to find out where to get that from.

[redlaser666]

The valves you can get from clippard or any of their distributors if you have one near.

[toymachine]

Originally Posted by Rage 01

Thankx for the info. I think as soon as it gets here, the new project on my lathe will be a ss piston. I will keep you posted on how that works.
I guess I better order a actuating valve as well just in case.
I will go threw the post to find out where to get that from.

talk to joedirt, you can find one of his posts a page or two back to pm him, he found a way (what redlaser666 said) to get valves way cheaper than the 20 or 40 or whatever metadyne offers them for (no idea on the actual number, I just know it's significantly higher), and he might still have an extra one to sell you.

a legit ss piston would be awesome! I look forward to your project

if ss doesn't work, is it on to some crazy ti compound then?!

Edit: I'm not saying ss won't work

[splattttttt]

Originally Posted by capitalpaintball

My thought is that: the air filling the dump chamber is just escaping for a fraction of a second before the piston head seals the chamber.
I am going to try a spacer between the head and the shaft but I dont want to make the piston to long.

looks to me like the pring groove has enogh space for one more oring.

[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.

[toymachine]

^I've tried the same thing with the older problematic pistons and had the same results as capitalpaintball

I'd love to see your spacer idea and/or hear a little more about how you think it'll help/work btw