Author Topic: JSAR SS Valve is better than ever! (Read 9255 times))

mann · « **Reply #40 on:** October 14, 2018, 12:54:37 PM »

Allorings.com has fep encapsulated o-rings ptfe encapsulated and several different cores that are encapsulated so if anyone know oring sizes for SS valve that would be great

oldpro · « **Reply #41 on:** October 14, 2018, 01:48:41 PM »

4.5mm x 1mm and 5.5mm x 1 mm

mann · « **Reply #42 on:** October 14, 2018, 01:55:17 PM »

Thanks Travis

HunterWhite · « **Reply #43 on:** October 14, 2018, 02:50:51 PM »

Is this "stiction" only observed when using regulator?

Motorhead · « **Reply #44 on:** October 14, 2018, 02:54:56 PM »

Quote from: HunterWhite on October 14, 2018, 02:50:51 PM

Is this "stiction" only observed when using regulator?

most prevalent with heavy hammers and softer springs ...
If you use a light hammer with a heavier spring the impact and motion of the poppet within valve is so fast you get far less sticktion effect.

mann · « **Reply #45 on:** October 14, 2018, 02:55:58 PM »

No observed both regulated and unregulated

mann · « **Reply #46 on:** October 14, 2018, 02:58:30 PM »

First shot is still enough to change point of aim for a hunter I don't want to have to burn a shot hunting

mann · « **Reply #47 on:** October 14, 2018, 03:00:01 PM »

Other than that I like this valve alot once I got it to seal up

triggertreat · « **Reply #48 on:** October 14, 2018, 03:21:32 PM »

I have been testing daily since my posted string. I'm getting 809 to 815 on the first shot. 855 to 860 on the 2nd shot. I'm using a 50 gram MDS with a 12.5lb primary and a 14.8lb inner spring. Basically, the primary spring is flush (no preload) The inner 14.8lb is a 1/4" shorter than the primary spring. If I add any preload to the primary spring, I would have to back off on the inner spring even more. I don't no if adding a heavier spring in the mix will work, but worth a try. I'll pull the valve and clean the thimble again and see if any rubber residue is in there. I have seen some in the past with a new poppet.

PCPhack · « **Reply #49 on:** October 14, 2018, 03:31:25 PM »

Did you try a tune with a smaller jet? I solved it for now on my Bulldog with a .015 jet, and more spring, along with a tune that expects the stiction, so a bit extra spring.

I am interested in FEP oring results, as I would like to go back to my higher power tunes, but then I need to open the jet up again. I asked Travis about FEP in one thread about the stiction, but didn't get a direct answer if he had tried that specifically.

triggertreat · « **Reply #50 on:** October 14, 2018, 03:42:46 PM »

Quote from: PCPhack on October 14, 2018, 03:31:25 PM

Did you try a tune with a smaller jet? I solved it for now on my Bulldog with a .015 jet, and more spring, along with a tune that expects the stiction, so a bit extra spring.

I'm using a .037" jet. The jet only affects the closing speed. I was using a .060 jet, but dropped it down seeing's how the cocking was still doable. 56 FPE with a 50 gram MDS is a tall order and requires a lot of spring already, even ported at .220 with a 2225 set point.

mann · « **Reply #51 on:** October 14, 2018, 04:22:42 PM »

Yes it is a tall order I'm using a 30 gram mds hammer and 12 spring with a good amount of preload and am getting stiction . I put out for a quote at allorings.com for price and availability for fep encapsulated o-rings and a couple other orings . They also have xrings but I would imagine they wouldn't help any being more sealing surface

shorty · « **Reply #52 on:** October 14, 2018, 05:00:11 PM »

I have never understood the stiction thing.

Do you guys think that first shot is harder to open and not getting the lift?
Or
The valve does open and the valve closes faster (Dwell)?

Is there a possibility that the poppet to thimble o ring is leaking.Just going to through this out there, what happens if you don't use o rings on the poppet?

Check out this website about dynamic o rings.
http://www.applerubber.com/hot-topics-for-engineers/what-you-need-to-know-about-dynamic-seal-applications/

I wonder if something like this is happening where the o ring is extruding and hanging up.

shorty · « **Reply #53 on:** October 14, 2018, 05:08:12 PM »

I think Huma regs use a HARD square o ring on the pressure adjustment screw ?

shorty · « **Reply #54 on:** October 14, 2018, 05:33:52 PM »

I wonder if PTFE coating the inside of the thimble would decrease the stiction ?

I have been working a lot lately with electropheric polymers as a conformal coating. At only 8um/10um film thickness I would be curious if the poppet/oring would still fit.

On Monday back at work, I will be working on a PTFE version.

Instead of coating the inside of the thimble, can one make a thin wall Teflon insert ?

mann · « **Reply #55 on:** October 14, 2018, 05:44:53 PM »

I think it's opening harder on the first shot some lubes have helped for a bit

nervoustrigger · « **Reply #56 on:** October 14, 2018, 07:35:41 PM »

If extrusion is a contributing factor, what would help is some combination of a higher durometer O-ring and/or reducing the gap between the parts.

HunterWhite · « **Reply #57 on:** October 14, 2018, 08:31:34 PM »

Some of the powder burner guys will embed a dry lubricant into the bullets, or the barrel. I don't know the physical layout of the valve, but is it possible to treat the metallic components with a dry lubricant like HBN (hexagonal boron nitrate) or molybdenum di something?

Motorhead · « **Reply #58 on:** October 15, 2018, 01:46:25 AM »

Quote from: shorty on October 14, 2018, 05:08:12 PM

I think Huma regs use a HARD square o ring on the pressure adjustment screw ?

Nope ... they just get Hard and Square after a year or more.

jarmstrong · « **Reply #59 on:** October 15, 2018, 02:10:15 AM »

https://www.theoringstore.com/index.php?main_page=index&cPath=14

here is a thought from my monkey brain..a backup ring on one side of the o-ring $:-\$

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JSAR SS Valve is better than ever!

Author Topic: JSAR SS Valve is better than ever! (Read 9255 times))