How to Fix a Liberty / Freedom / Aspen Valve Poppet

[FuzzyGrub]

The white 5/16" Delrin rod came today.  The next poppet will be for my original Liberty and it will be white. 

[wll2506]

The white 5/16" Delrin rod came today.  The next poppet will be for my original Liberty and it will be white. 

Awesome..... looking forward to your report.... my Delrin comes next week :-)

wll

[Madd Hatter]

IMHO I don't see why you'd want to keep the metal can and it seems to me that drilling the hole for the stem should be the first step so the poppet face is perfectly square to the stem. But that's just me.

[FuzzyGrub]

IMHO I don't see why you'd want to keep the metal can and it seems to me that drilling the hole for the stem should be the first step so the poppet face is perfectly square to the stem. But that's just me.

If I had a lathe, I'd probably ditch the can.   You would need to have the step for the spring guide, so would need to start with a larger OD rod, like the 3/8".  ie the spring OD is about the same as the can OD.  Given the larger OD, you can't use the can for the pilot to find the center of the rod, for the drilling.  I think it can be done with caveman tools, just more steps and more areas for something to get messed up.   Also, don't think the can will be an issue.  The seat would have to wear into the Delrin the height of the seat + 0.020".   I have seen rings in crosman Delrin poppets, but much more shallower than what I've seen on these two poppets. 

It is only perfectly square if the mfg made a nice clean cut, and then only the ones on each end.    That said, the rod I have was cut well.   

[Madd Hatter]

I didn't mean to say it wasn't cut square but it doesn't take much to drill the hole for the stem a little crooked.

[FuzzyGrub]

it doesn't take much to drill the hole for the stem a little crooked.

I am normally the guy that can't drill a straight hole without a guide.       I think the rotating stock helps and will find out when I make the next one.  I never get lucky twice in a row.     I also think that the Delrin is more forgiving than if I tried peek.

Looking at the stub of Delrin I had left from making the other two poppets, I think I can make a can-less one out of it. 

Once Will gets his lathe up and makes a bunch of these inserts, I recommend anyone that has a Liberty, Freedom, or Aspen to grab one.  Very generous offer on his part.  These guns will need the poppets replaced at some point.   What I see as a challenge, others just see as a PITA to do.   

PS: Both guns holding air, rock solid.  I thought there was a good chance that gun #2 had a leak somewhere else. 

[nervoustrigger]

Just a heads up for anyone looking to make a replacement poppet with hand tools, don’t sweat it if you don’t get the hole in the poppet drilled perfectly.  You can true the sealing face with sandpaper.  Drill a close-fitting hole for the stem in a thick piece of wood…thick enough to support most of the length of the stem, with just a little bit sticking out the other side that you can grab with your drill chuck.  Now take a piece of sandpaper and use a hollow punch or leather punch to make a series of holes big enough for the stem can pass through.
 
Lay the sandpaper over the wood and put the stem through both pieces.  In other words, trap the sandpaper between the poppet and the piece of wood.  Grab the stem from the other side with your drill and spin it to work down the sealing face.  Don’t go so fast that the plastic melts.  Fine sandpaper will tend to clog so move to a fresh location as needed.
 
It helps to color the surface with a magic marker so you can see the low spots as you go.  Once all the marker is gone, you’re good.
 
Try your best to drill the hole in the wood as true (perpendicular the surface) as you can, but even if you are off by few degrees, it will still work.  You will end up with a subtle taper to the sealing face but it will be true to the stem.  So whether the valve has a flat sealing face or a raised ring, it will seal fine.
 
As usual, it’s a good idea to do a final burnish of the poppet against the valve with a light abrasive.  Color the face again with a marker and use that to see how well it’s mating.  When the marker is removed uniformly around the full circumference, you know it’s going to seal fine.

[Nvreloader]

Guys

Question for you,

What is the "C" clip on the shaft used for, to hold the poppet can/head on the shaft,
because the inside material of the can/poppet is so soft etc ??

Tia,
Don

[FuzzyGrub]

Guys

Question for you,

What is the "C" clip on the shaft used for, to hold the poppet can/head on the shaft,
because the inside material of the can/poppet is so soft etc ??

Tia,
Don

I think the metal can is to prevent the soft material from mushrooming out to the sides, from repeated impacts to the valve, and the C-clip is just to keep the can from coming off inside the gun.   It is a rather thick clip, which suggests it is providing structural support.   The oem material is significantly softer than the Delrin.

[FuzzyGrub]

Just a heads up for anyone looking to make a replacement poppet with hand tools, don’t sweat it if you don’t get the hole in the poppet drilled perfectly.  You can true the sealing face with sandpaper.  Drill a close-fitting hole for the stem in a thick piece of wood…thick enough to support most of the length of the stem, with just a little bit sticking out the other side that you can grab with your drill chuck.  Now take a piece of sandpaper and use a hollow punch or leather punch to make a series of holes big enough for the stem can pass through.
 
Lay the sandpaper over the wood and put the stem through both pieces.  In other words, trap the sandpaper between the poppet and the piece of wood.  Grab the stem from the other side with your drill and spin it to work down the sealing face.  Don’t go so fast that the plastic melts.  Fine sandpaper will tend to clog so move to a fresh location as needed.
 
It helps to color the surface with a magic marker so you can see the low spots as you go.  Once all the marker is gone, you’re good.
 
Try your best to drill the hole in the wood as true (perpendicular the surface) as you can, but even if you are off by few degrees, it will still work.  You will end up with a subtle taper to the sealing face but it will be true to the stem.  So whether the valve has a flat sealing face or a raised ring, it will seal fine.
 
As usual, it’s a good idea to do a final burnish of the poppet against the valve with a light abrasive.  Color the face again with a marker and use that to see how well it’s mating.  When the marker is removed uniformly around the full circumference, you know it’s going to seal fine.

Thx Jason    You are the supreme expert in caveman approaches!   

I do have a small bench-top drill press, that would make the above easier.  Just have to make sure the table is square.  So far, that hasn't been needed. 

[nervoustrigger]

Yes sir!

[Madd Hatter]

I love it!!! For those of us who are still cave dwellers with our equipment !!!!! I do so miss not having access to a mill and lathe.

[nervoustrigger]

About the retaining clip, I suspect it is also an insurance policy against the stem ejecting out the back of the valve with 4000psi behind.  Look out!
 
The friction holding it is probably more than sufficient…until such time as the elastomer degrades some years down the road, or until an owner applies some cleaner or lube that attacks it.  That’s the sort of stuff the design engineers and safety engineers are thinking about.

[FuzzyGrub]

Making one from the 5/16" rod.  The OD need to be slightly sanded to fit the inside of the metal cup.  The drilling method also produced a centered hole through the length of the Delrin I was working with.  Looking good to complete poppet #3.

[wll2506]

Making one from the 5/16" rod.  The OD need to be slightly sanded to fit the inside of the metal cup.  The drilling method also produced a centered hole through the length of the Delrin I was working with.  Looking good to complete poppet #3.

What size hole did you drill ..... also what is the length of the Delrin poppet ?

Also ------ did you trim back any of the steel poppet shell to keep the same OAL ?

wll

[FuzzyGrub]

Making one from the 5/16" rod.  The OD need to be slightly sanded to fit the inside of the metal cup.  The drilling method also produced a centered hole through the length of the Delrin I was working with.  Looking good to complete poppet #3.

What size hole did you drill ..... also what is the length of the Delrin poppet ?

Also ------ did you trim back any of the steel poppet shell ?

wll

Will,  I basically followed the procedure above.  The final drill size was a #22, which should be around 0.156".   I removed 0.030" from the metal can rim, and the Delrin now extends about 0.035" below the lip of the can.   

[wll2506]

Making one from the 5/16" rod.  The OD need to be slightly sanded to fit the inside of the metal cup.  The drilling method also produced a centered hole through the length of the Delrin I was working with.  Looking good to complete poppet #3.

What size hole did you drill ..... also what is the length of the Delrin poppet ?

Also ------ did you trim back any of the steel poppet shell ?

wll

Will,  I basically followed the procedure above.  The final drill size was a #22, which should be around 0.156".   I removed 0.030" from the metal can rim, and the Delrin now extends about 0.035" below the lip of the can.

Thank you very much ... I may change my drill size from .166 to.156 , and trim back the shell a few thousands.

wll

[FuzzyGrub]

Long story short, I broke the stem right where the c-clip goes.  Dug out the stub of 3/8" Delrin, left over from the first two poppets, and made a blind hole version of the poppet.  Not as clean as I'd like on the step for the spring, but it is what it is.  Holding air for now. 

[FuzzyGrub]

It's been one of those days!      I took the gun down to the basement range, and half way through a mag, the poppet starts a massive leak.   I had a picture of Robert's broken poppet in my mind.   Tore it down, but the poppet was in tact.  It was a piece of broken E-clip stuck between poppet and valve.   It put a small ding in the Delrin, but outside of the sealing area. 

[FuzzyGrub]

It's been one of those days!      I took the gun down to the basement range, and half way through a mag, the poppet starts a massive leak.   I had a picture of Robert's broken poppet in my mind.   Tore it down, but the poppet was in tact.  It was a piece of broken E-clip stuck between poppet and valve.   It put a small ding in the Delrin, but outside of the sealing area.

It looks like I have a nick in the valve seat from the broken E-clip.     Will have to pull the valve.  Hopefully, it is not too deep.