Tuning Cobra valve tech built into raw valve

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Airgunmann

Airgunmann

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Jun 2, 2018
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Minnesota, United States
My thoughts are to remove the end on the plug that holds the spring use what is left of the rod to fit in a tube and keep it straight and install a oring on the poppet to incorporate cobra valve tech into the raw valve to slam the valve shut controlled by the office hole any thoughts or opinions on design would be great but I think it would easy enough to do 
 
Been running one for quite a few years now in my TM-1000 .... good luck in the fabrication, very doable !



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Inside the tube sits a light spring so gun can be filled from empty. Black cup sits in the Access cap pocket. it does use a custom aluminum valve body tho which is shorter in height to allow space for these COBRA components.
 
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Been running one for quite a few years now in my TM-1000 .... good luck in the fabrication, very doable !



DSCF0403_70.1633325258.jpg


DSCF0402_70.1633326463.jpg




Inside the tube sits a light spring so gun can be filled from empty. Black cup sits in the Access cap pocket. it does use a custom aluminum valve body tho which is shorter in height to allow space for these COBRA components.
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That is great Scott 

Will it work on high power RAW HM1000X guns.

What kind of reliability, durability and consistency do you achieve by this set up?

What benefits?

Please share if you like.

Regards, 



Bhaur
 
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OK .. you asked, sit down and have Looong read : https://www.gatewaytoairguns.org/GTA/index.php?topic=139401.msg1402661#msg1402661



Every "REGULATED" PCP in my collection has a "Cobra" air spring conversion fabricated and fitted. Primary want is that of EFFICIENCY and with tuning with vent size and making sure chamber has enough volume to be effective can find a happy medium in chopping dwell w/o effecting power by much if any. End result a quieter PCP with reduced air use.



Scott S
 
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IF you want to see how to retrofit a Marauder valve ? Here is that link : https://www.gatewaytoairguns.org/GTA/index.php?topic=149519.msg1525979#msg1525979



Do understand that ALL OF THIS was R&D and proof of concept testing and multi gun trials to see if indeed the attributes carried over across all .. IT DID !!

Fabrication skills & Lathe required being really not a bit of work one can cobble together ... sadly.
 
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I'm going to pick up some aluminum and give it a go I'll set my peek poppet off to the side make a new one and fit aluminum chamber to the spring guide which should line everything up and start out with a .030 hole and reg at 150 the hole will probably need adjustment but any suggestions motorhead ? Chamber depth or size and hole size to start with thank you for any help . I'm excited to give it a try to see what it can do I know they are efficient I had a couple which I sold for marauders a couple years ago it would be my first go at a cobra valve but I was successful at building a simplified balance valve that Bob stern had us testing including himself it should be easier than that was won't have to drill threw the stem like on that thanks for any help or suggestions that you could give 
 
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Creativity of making an adjustable needle valve as the venting miens is doable. I've got nothing on paper, but the idea is valid enough.
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I feel that if we can make adjustable piston chamber of the balanced valve, it can act as adjustable spring.

If we need more power behind the valve we can adjust the piston chamber a bit smaller and if we need less power behind the valve we can increase the area of piston chamber by just adjusting one screw.

Do I make sense!!!

Bhaur
 
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Further I have noticed one thing that FX valve design is of such nature that one end of valve stem always opens in Atmospheric pressure.

I understand this is the reason that in FX Royal 400 the valve spring is extremely light, hammer weight is also light and hammer spring is also nice.

Under the above concept I understand that in RAW guns if I open one end of valve stem in Atmospheric pressure, the required force to crack the valve will be decreased, I will need lighter valve spring, lighter hammer and lighter hammer spring and shall achieve the same objective as can be obtain through balanced valve concept. 

Please opine.

Bhaur
 
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Balanced valves and Cobra air springs are two entirely different animals ...



Changing vent size in a COBRA ... Larger the vent size less is the closing effect and = longer dwell. Smaller vent stronger is the closing effect.



Changing Vent / Bleed hole in a Balanced has the reverse effect ... Smaller the bleed, slower balance chamber fills sending poppet back to the seat resulting in longer dwell. Larger the bleed hole FASTER the balance chamber pressurizes sending poppet back to seat and shorter will be the dwell.



Scott S
 
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