Noob air seal question

[Sjkendall]

I am currently trying to track down an air seal  issue, So before I open up the gearbox to further investigate I was wondering if the below video is normal, 

 

the metal circular seal doesn’t fit in permanently or click in place etc. is it normal for this piece to be freely sliding up the barrel ?. 
 

thanks 

Edited July 11, 2024 by Sjkendall

[Enid_Puceflange]

Apply a bit of pressure , it should slip in between the front of the hop unit and barrel, helps to keep the barrel tight to the hop unit

[The_Lord_Poncho]

Yes, some tighter than others. I've had both extremes - a very tight fit (eased with a bit of silicone oil), and very loose fit (rectified with a few wraps of PTFE tape). If you are needing force to seat yours in this case, after you have finished wrestling with it take care that the barrel hasn't got twisted within the hop (and therefore that the nub remains directly seated above the bucking patch).

[Shamal]

It's not a seal in any sense bud it just helps to take up any slack between the barrell and hop.

[Sjkendall]

Thanks for the help guys. 

 

another noob questions… 

 

when I cover all holes ( bb receiver + end of the barrel) and I blow through the other end there is a slight ( very slight ) leak of air going somewhere. Is this normal ?? 
 

thanks 

 

7 minutes ago, Shamal said:

It's not a seal in any sense bud it just helps to take up any slack between the barrell and hop.

Thanks

[Colin Allen]

3 hours ago, Sjkendall said:

when I cover all holes ( bb receiver + end of the barrel) and I blow through the other end there is a slight ( very slight ) leak of air going somewhere. Is this normal ?? 

If there is a very slight leak, that is probably normal as the sealing of the ends may not be perfect.

 

With the gun assembled and the nozzle fully forward, shine a light up the BB feed tube and look down the barrel; if you can see a ring of light, the nozzle is not sealing in the hop lips.

 

[ak2m4]

Give us some fps stats, also have you changed anything (I can see a spring in the video), is it all stock etc etc etc. 

[Sjkendall]

 

30 minutes ago, ak2m4 said:

Give us some fps stats, also have you changed anything (I can see a spring in the video), is it all stock etc etc etc. 

With an m120 spring it’s 310fps 1.01 joules. So way under the performance of that spring, everything is stock other than the spring , the stock spring was a m100 and was only getting 240 fps 

 

0.25 BBs

2 hours ago, Colin Allen said:

If there is a very slight leak, that is probably normal as the sealing of the ends may not be perfect.

 

With the gun assembled and the nozzle fully forward, shine a light up the BB feed tube and look down the barrel; if you can see a ring of light, the nozzle is not sealing in the hop lips.

 

Will try thanks

Edited July 11, 2024 by Sjkendall

[Colin Allen]

51 minutes ago, Sjkendall said:

With an m120 spring it’s 310fps 1.01 joules. So way under the performance of that spring, everything is stock other than the spring , the stock spring was a m100 and was only getting 240 fps 

That is very poor; what is the length of the inner barrel?  Do you have a photo of the cylinder showing the window?

[Sjkendall]

1 hour ago, Colin Allen said:

That is very poor; what is the length of the inner barrel?  Do you have a photo of the cylinder showing the window?

380mm the inner barrel, its a vfc avalon rapier the barrel is quite big. , a photo of what mate? sorry im a noob. 

i did what you suggested about shining a light, i do see the light through the barrel constantly. when i look up the bb feeding tube, the nozzle from the lower receiver only covers the hole when i fire the RIF. (the nozzle cannot be seen through the feeding tube unless i fire for a split second ) 

[Lozart]

If any of the multitude of VFC teching videos are anything to go by, the piston probably fits like a dick in a shirt sleeve.

 

How up for ripping it apart and tinkering are you?

[Sjkendall]

5 minutes ago, Lozart said:

If any of the multitude of VFC teching videos are anything to go by, the piston probably fits like a dick in a shirt sleeve.

 

How up for ripping it apart and tinkering are you?

im totally up for taking it apart, just all new to me so dont know terminology, part names etc etc. 

so the piston is known to not fit very well in its surround ?

Edited July 11, 2024 by Sjkendall

[Sjkendall]

Is this normal operation for the tip?. I’ve seen on other videos it retracts first then pushes forward with the air ?

[Shamal]

30 minutes ago, Sjkendall said:

Is this normal operation for the tip?. I’ve seen on other videos it retracts first then pushes forward with the air ?

IMG_9229.mov

Not 100% sure but is the gun working?

[Sjkendall]

23 minutes ago, Shamal said:

Not 100% sure but is the gun working?

Yeah all works and feeds fine. Just a loss of pressure somewhere  

[Shamal]

45 minutes ago, Sjkendall said:

Yeah all works and feeds fine. Just a loss of pressure somewhere  

Ok so it works pretty good that's a start. How about that air nozzle. It looks like an old plastic one and some of the plastic air nozzles didn't have an o ring. Could be loosing some pressure there.

I'm guessing you have checked the hop up bucking for holes?

[Sjkendall]

32 minutes ago, Shamal said:

Ok so it works pretty good that's a start. How about that air nozzle. It looks like an old plastic one and some of the plastic air nozzles didn't have an o ring. Could be loosing some pressure there.

I'm guessing you have checked the hop up bucking for holes?

 

yeah hop up and bucking are intact :), the air nozzle is plastic i cant tell if there is an o ring or not in place, it is a vfc avalon v2 gearbox. think its time to bite the bullet and open the gear box 

[Shamal]

1 hour ago, Sjkendall said:

 

yeah hop up and bucking are intact :), the air nozzle is plastic i cant tell if there is an o ring or not in place, it is a vfc avalon v2 gearbox. think its time to bite the bullet and open the gear box 

Yeah I think it would be good to check if that nozzle has an o ring. Plus you can check the rest of the compression side of things. V2 boxes aren't that scary.?

[Colin Allen]

1 hour ago, Shamal said:

Yeah I think it would be good to check if that nozzle has an o ring. Plus you can check the rest of the compression side of things. V2 boxes aren't that scary.?

The compression on VFCs out of the box is usually awful, which could be a major part of the problem.

[Sjkendall]

25 minutes ago, Colin Allen said:

The compression on VFCs out of the box is usually awful, which could be a major part of the problem.

Aye the compression on the piston is pretty naff. Would you suggest a new piston from a different brand ?

2 hours ago, Shamal said:

Yeah I think it would be good to check if that nozzle has an o ring. Plus you can check the rest of the compression side of things. V2 boxes aren't that scary.?

Thanks mate. Yeah there is no o ring on the nozzle however I cannot see anywhere where on may go. 
 

checked the inside of the gearbox and the compression isn’t the best 

[Shamal]

20 minutes ago, Sjkendall said:

Aye the compression on the piston is pretty naff. Would you suggest a new piston from a different brand ?

Thanks mate. Yeah there is no o ring on the nozzle however I cannot see anywhere where on may go. 
 

checked the inside of the gearbox and the compression isn’t the best 

O rings are built into the nozzle. You can get single or double o rings but single work just as good. You will need to measure the length of the nozzle to get the right one.

[Sjkendall]

1 hour ago, Shamal said:

O rings are built into the nozzle. You can get single or double o rings but single work just as good. You will need to measure the length of the nozzle to get the right one.

thanks for the help mate (the seal was missing ). just purchased a new piston head, cylinder head and nozzle. hopefully solves my problems. 

[Colin Allen]

3 minutes ago, Sjkendall said:

thanks for the help mate (the seal was missing ). just purchased a new piston head, cylinder head and nozzle. hopefully solves my problems. 

Replacing the piston head O ring would be a good idea if the new one does not come with one.

[Sjkendall]

11 minutes ago, Colin Allen said:

Replacing the piston head O ring would be a good idea if the new one does not come with one.

good point, just purchased a set so hopefully they do come with, will double check

[ak2m4]

Also make sure you have some silicone grease for the orings as well... I sell a little kit but you use anything that's suitable for orings. 

 

You want the fitment on the nozzle to be tight but not overly tight where it restricts movement.

 

Same with the oring on the piston head, needs to seal but not be too tight.

 

 

Edited July 13, 2024 by ak2m4