ATI Libert/Freedom Custom valve

[cosmic]

I asked him for bolt probe o rings.. No response. Duy sent me some and provided the measurements..

[USAFANG6799]

I asked him for bolt probe o rings.. No response. Duy sent me some and provided the measurements..

Fantastic!
Good reliable source for the inevitable.

[Madd Hatter]

Who knows, we might be able to get replacement parts from Pyramyd Air. The do sell the liberties brother the freedom aka Aspen and it uses a lot of parts that are the same.

[huklbery]

Who knows, we might be able to get replacement parts from Pyramyd Air. The do sell the liberties brother the freedom aka Aspen and it uses a lot of parts that are the same.

Evanix seems to have disappeared from Pyramyd/Airgun Depot, thought that was odd and I wonder about future support. 

I had called to get Diana Chaser (SPA) CO2 piercing pin seals just got crickets in response.  Would be nice if someone did the ArcherAirgun QB style support for SPA & Nova Vista products.   

Many of the O Rings on the Nova Vista are listed by size and durometer on the CAD Drawings.  Oddly enough the bolt probe o ring looks like part number rather than size though. 

[FuzzyGrub]

Many of the O Rings on the Nova Vista are listed by size and durometer on the CAD Drawings. 

Just be aware that those in the drawings are metric CS X OD, not the more standard way of CS X ID.   I have a few bags of useless, too large O-rings.     

[huklbery]

Many of the O Rings on the Nova Vista are listed by size and durometer on the CAD Drawings. 

Just be aware that those in the drawings are metric CS X OD, not the more standard way of CS X ID.   I have a few bags of useless, too large O-rings.     

Hahaha yep did the exact same thing when I ordered the O rings to make a plenum extension ;-).  Went with McMaster carr this time and could call it up by ID & OD & material dia unlike Amazon and ordered the proper/listed durometer   

Making these tidbits is fun but gets expensive when you add up materials and tooling.  It's like the crafts projects you spend $100 for some import product that costs $60 retail but your thinkin hey I can make that.... 

[Madd Hatter]

You mean like just about every hobie out there??

[darkcharisma]

Mark. the extensions look good. if you ever feel like the extensions are not enough. try making a standalone larger bore plenum.

Fuzzy there aint no way i can fit 60cc on this gun unless i am really desperate and tap the side of the breech for a gauge but instead use a plenum... like in my drawing i posted. 25cc is reasonable

Heath, there aint no oem power wheel replacements, ya gotta turn ya own. the ones i know of is buying a $100 ati parts gun.

yah guys ihave 4 packs from the oring store gonna use it for something else. Ray has been the most patient cat ever. lol usps had his package lost for a couple of weeks and then i went on two separate vacations seems like every time he sends in his gun.

oh yeah, still recovering from loss of sleep and the long drives. i saw a lot of dust storms from little tornados and a lot of scary down hill drives at night in New Mexico...

was going to teat last night but was to late to turn the compressor on for the shoebox

[FuzzyGrub]

Fuzzy there aint no way i can fit 60cc on this gun unless i am really desperate and tap the side of the breech for a gauge but instead use a plenum... like in my drawing i posted. 25cc is reasonable

You asked what Bob would suggest.     25cc is great for the space constraints you are working with.

Most pcps are limited to 3k fill, so it quickly becomes a major trade-off between plenum size and air supply. 

On the Liberty, you could set the reg point to 3K and still have over 1kpsi to work with. 

[darkcharisma]

the liberty's hammer is made of feathers. even with the extra hammer weight i put in Rays gun it is now unable to knock open the valve. making the rifle very efficient right now. when at first i tested it, i was getting 15.5 grains nsa slugs to go 980fps. now? with a 4k fill it will do 550fps and 880fps with 18grs at 2800psi. this is all from increasing the reg with no gauge.

3000psi would need some heavy hammers. it may already be at 3k on Rays gun. sorry Ray you gotta turn it down

[huklbery]

Mark. the extensions look good. if you ever feel like the extensions are not enough. try making a standalone larger bore plenum.

I was offput by the face O Ring,  doing a lathe trepann would be problematic.  I don't have a rotab or a CNC hook up on the mini mill.

My thinking on the extension however is with the receiver out of the stock I can stack the extensions and see where the chrony takes the tune.  If it does work out that the gain is real and the diminishing return point is reasonable, it will extend in the area a conventional rifle's mag does. 

All this of course is a balance, as the hammer/spring/valve is pushed I suspect bounce loss would go up.  I'm looking forward to what the chrony results show.  I must admit, I was a bit disappointed in the results of going to .187 barrel port and up sizing the adjusters port.  Somewhere around a 1 to a 1.5 fps gain in my case. 

I'm crossing my fingers the plenum will produce a 4 or more fps gain, if not I doubt I will through bore the stock.   

All that said, I ordered some 5/64 end mills to try lashing a dremel to the lathe toolpost to do that face O Ring.  What could go possibly wrong.... 

[huklbery]

1

[Madd Hatter]

the liberty's hammer is made of feathers. even with the extra hammer weight i put in Rays gun it is now unable to knock open the valve. making the rifle very efficient right now. when at first i tested it, i was getting 15.5 grains nsa slugs to go 980fps. now? with a 4k fill it will do 550fps and 880fps with 18grs at 2800psi. this is all from increasing the reg with no gauge.

3000psi would need some heavy hammers. it may already be at 3k on Rays gun. sorry Ray you gotta turn it down

The funny thing is is the hammer spring and hammer on the freedom will work just fine at 3000 psi. Is it a different hammer or spring or just the adj?

[darkcharisma]

Robert i have the Freedom. at 3000psi i was getting less fps then at 2600psi. i think the sweet spot is at 2600-2800psi. and i havent touch the adjusting feature. it probably is the same parts but having no gauge is the problem right now...just hate to be in the unknown. im getting to the bottom of that problem next couple of days. but plenum testing tonight

Mark, i would get a groove cutter with full radius and turn it towards the face and mill it that way to avoid chatters if any with the attached dremel.

whats your maximum fpe with those mods?

[darkcharisma]

whoooo wooo! the new valve works! just talked to Ray and we clocked a new speed beyond 980fps for 15.5gr nsa slugs in .177 cal. said he would do some more testing and shot string tomorrow. hope nothing is impeding his schedule so he can do us some good airgun research. nothing gets me more exciting than getting some good results!

[FuzzyGrub]

I think Stephen has been running at 2.7k psi with stock valve plus Delrin poppet.  He might be using his hammer spring adjuster but think the stock spring.   

I agree adding weight to hammer is a challenge.  Have you tried dual springs?

[darkcharisma]

i have not tried dual springs but adding weight was an easy job. we could use a stronger spring too. the hammer weight opens up new unreached levels of fpe. i have not tested it on my liberty. but i will soon.

[Madd Hatter]

Robert i have the Freedom. at 3000psi i was getting less fps then at 2600psi. i think the sweet spot is at 2600-2800psi. and i havent touch the adjusting feature. it probably is the same parts but having no gauge is the problem right now...just hate to be in the unknown. im getting to the bottom of that problem next couple of days. but plenum testing tonight

Mark, i would get a groove cutter with full radius and turn it towards the face and mill it that way to avoid chatters if any with the attached dremel.

whats your maximum fpe with those mods?

I have mine set at 1 turn out from bottomed and the vel really starts at the that pressure.

[huklbery]

Finished an extension plenum and mounted it to test the results.  Neglected to input the pellet weight for the 1st test run with stock air volume.  Was a little surprised as this is running a bit hotter than the last time I had tested it (890-910 fps 18.1g JSB jumped up to 930avg).

Added the extension plenum, the inside is dimensionaly the same though the front has a 9mm bore for the back 16mm threads vs the front's 10mm.  Roughly double the volume...  and it only pushed it 28 fps
 faster in this state of tune.

Nova Vista keeps impressing me with the package as delivered.   At 26ftlbs state of tune I don't think upping the plenum returns all that much.  I had suspected the small volume, turns out its not that bad as delivered. 

Next I need to make a plenum butt plug with a gage.  This exercise leaves me wondering where on the pressure scale my two samples are now.   

I'm curious as I take the pressure up *if* that plenum volume gives larger returns as I would suspect.  These plenums are stackable so larger volumes will be proofed for testing as well... 

[FuzzyGrub]

Next I need to make a plenum butt plug with a gage.  This exercise leaves me wondering where on the pressure scale my two samples are now.   

Yes, it comes off the reg so gradual, it is hard to tell exactly where the set-point is. 

What porting are you running?