Quick explanation of the power tube spacers

[georgeyew]

Guys, I've searched all of the treads on this subject and I have not been able to find a decent explanation on how the power tube spacers work. Could one of you educate me real quick? I know that ADG says that if there is a leak use a shorter spacer and if there is a bolt stick use a longer one. But here is where I get confused. If I used a longer spacer wouldn't it compress the o-ring more making the opening tighter? So wouldn't a longer spacer be better at stopping the leak instead of the bolt stick? I know that ADG can't be wrong, so I am trying to figure out what I am not understanding correctly. Thanks for your help.

[Coralis]

The power tube spacers actually are used to adjust the position of the powertube oring, a shorter one allows the oring to be more forward in the stem and a longer one pushes the oring back farther as I understand it.

[michbich]

If your getting bolt stick, put in a shorter power tube spacer

If your getting barrel leak, put in a longer one.

The spacers adjust where the pin inside the bolt seats on the power tube o-ring. You want to have it set where the bolt pin can get past the seal of the o'ring, but also seat far enough so it seals and keeps the dump chamber from leaking while it refills for the next cycle.

Taken from chapter 4:

http://www.automagsuk.com/classicandrt.html

[georgeyew]

If your getting bolt stick, put in a shorter power tube spacer

If your getting barrel leak, put in a longer one.

Taken from the ADG site: http://www.airgundesignsusa.com/down...plodedview.pdf

"If your marker has bolt stick use a longer one, if it leaks down the barrel use a shorter one."

What the ADG manual says is different than what you posted...I wonder why?

[snoopay700]

If your getting bolt stick, put in a shorter power tube spacer

If your getting barrel leak, put in a longer one.

The spacers adjust where the pin inside the bolt seats on the power tube o-ring. You want to have it set where the bolt pin can get past the seal of the o'ring, but also seat far enough so it seals and keeps the dump chamber from leaking while it refills for the next cycle.

Taken from chapter 4:

http://www.automagsuk.com/classicandrt.html

Barrel leak is a shorter one.

[michbich]

I just copy/pasted the info from the site.

[BlackVCG]

I just copy/pasted the info from the site.

That site is not an official site and is not part of AGD. Their info is incorrect and needs to be updated.

[Spider-TW]

"If your marker has bolt stick use a longer one, if it leaks down the barrel use a shorter one."

Good, this fits what I was thinking. I wer cunfusd.

[georgeyew]

I still don't understand what the oring spacing has to do with bolt stick and air leak

[Spider-TW]

The power tube oring is pushed forward by the dump chamber pressure and kept at the right distance by the spacer. If the distance is too short, the bolt will not release the pressure or will retain too much pressure to recock when the bolt returns. If the distance is too long, the bolt will not be able to seal.

The bronze springs let the oring ride back and forth as required, but the spacers take away that movement (a good thing for the seal) and don't get too short over time.

Any compression of the power tube spring forward under pressure (on the bolt stem) would delay the release of pressure and any movement back after that would delay the reseal of the tube. This must not have made much difference since spacers work fine.

[georgeyew]

Thanks. That makes sense now!

[DamianTC]

I am having the same problem, and still cant figure out what is going wrong. when I use a 215 spacer, I will get bolt stick and with a 220 I get no bolt stick but I will get some leak down the barrel. My leaking comes if I pull the trigger slightly before the gun fires it will start leaking. I replaced the power tube o-ring. This seems to happen more often when the gun is fired rapidly. I am thinking this is an issue with the bolt and o-ring freezing from CO2. if I am correct with this, would a compressed air setup fix this?

[Spider-TW]

I am having the same problem, and still cant figure out what is going wrong. when I use a 215 spacer, I will get bolt stick and with a 220 I get no bolt stick but I will get some leak down the barrel. My leaking comes if I pull the trigger slightly before the gun fires it will start leaking. I replaced the power tube o-ring. This seems to happen more often when the gun is fired rapidly. I am thinking this is an issue with the bolt and o-ring freezing from CO2. if I am correct with this, would a compressed air setup fix this?

If it is freezing, yes. Compressed air gets cool when you drop the pressure on it, but not enough to freeze. What kind of trigger do you have and how fast (and long) are you shooting?

[ajnin]

I always thought that a longer spacer will squish the oring more which is why if you have barrel leak you use a long one, your trying to create more of a seal. A shorter spacer obviously allows the oring to retain more of its original un-squished state.

[georgeyew]

I always thought that a longer spacer will squish the oring more which is why if you have barrel leak you use a long one, your trying to create more of a seal. A shorter spacer obviously allows the oring to retain more of its original un-squished state.

That's what I initially thought also, but apparently in the Level 7, the o-ring does not get compressed at all (unlike the Level 10).