A thought on a Discovery Pressure Regulator

A thought on a Discovery Pressure Regulator

Joined: August 20th, 2008, 5:32 pm

September 20th, 2008, 7:08 pm #1

Anyone:

I do not have a metal-lathe, but if I did, wouldn't it be cool to put add a 'hang-off' air resevoir on the end of the Discovery pressure tube and then machine and put a pressure regulator inside the original pressure tube? (I am such a geek!) For my Disco, if I could hold the transfer port presure to 1500# and fill the rest of the pressure tube upto something around 2500#, that would give lots of shots with the best shot string consistancy.

Seems like a machined plug with o-rings (installed in the pressure chamber similar to the hammer valve assembly)with a spring-valve pressure moderator inside would do the trick. Looking at a BSA PCP, I figure about one third of the volume of the existing Discovery pressure tube would be required for a sufficient volume of regulated pressure air - hence the add-on resevoir.

This may be too over-the-top, but I have always ben interested in regulated pressure air guns; and this is a cheap one to mod!

Scott
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Joined: September 8th, 2004, 8:08 am

September 21st, 2008, 3:01 am #2

But that's as far as it goes so far! It was my reasoning to control Co2 at hi-temps but I guess if done right it could work with air as well.


The idea is to place the reg. just ahead of the gauge adapter or even replace the adapter all together.

But first, since this is my first post here let me introduce myself. D R Greysun here, I live in the Southern Calif. desert where temps of 110 + are not all that uncommine. When most of the country is shivering we have our prime Co2 shooting temps. Co2 pressure can exceed 1250 psi with ease during our summer.

This is a project I started a couple of months ago.

I hope someday it will be a 'Match Class' bench rifle. With some valve mods I have been able to get between 6 FPE w/ 10.68 gr.CPH to 6.7 FPE w/7.7 gr. Daisy Max Speed WC. As you can imagine indoors at 78 to 80 deg F. It shoots with ideal consistency. However, out of doors it can get out of hand, hence the regulator idea.

D R


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Joined: April 7th, 2007, 8:31 pm

September 21st, 2008, 1:33 pm #3

I know with my rimfires it's a plus, but with no extra powder burn time needed in an airgun is the longer barrel a plus or not?

Enjoying the 70's here in NC.
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Joined: May 12th, 2001, 1:29 pm

September 21st, 2008, 1:50 pm #4

Anyone:

I do not have a metal-lathe, but if I did, wouldn't it be cool to put add a 'hang-off' air resevoir on the end of the Discovery pressure tube and then machine and put a pressure regulator inside the original pressure tube? (I am such a geek!) For my Disco, if I could hold the transfer port presure to 1500# and fill the rest of the pressure tube upto something around 2500#, that would give lots of shots with the best shot string consistancy.

Seems like a machined plug with o-rings (installed in the pressure chamber similar to the hammer valve assembly)with a spring-valve pressure moderator inside would do the trick. Looking at a BSA PCP, I figure about one third of the volume of the existing Discovery pressure tube would be required for a sufficient volume of regulated pressure air - hence the add-on resevoir.

This may be too over-the-top, but I have always ben interested in regulated pressure air guns; and this is a cheap one to mod!

Scott
...essentially doubling the complexity of a PCP powerplant, while contributing little to performance, consistency, or accuracy that can't be achieved in a simpler way: adding volume to the air reservoir.

Steve
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Joined: April 7th, 2007, 8:31 pm

September 21st, 2008, 1:53 pm #5

Did you mean can be achieved in a simpler way by a larger volume air reservoir?
Last edited by BuyMyJunk on September 21st, 2008, 1:53 pm, edited 1 time in total.
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Joined: May 12th, 2001, 1:29 pm

September 21st, 2008, 2:35 pm #6

...increasing reservoir volume. How's that?

Plus, a regulated gun is inherently less efficient in converting air expenditure into muzzle energy. This is due to the pressure drop indroduced by the regulator.

Steve
Last edited by pneuguy on September 21st, 2008, 2:37 pm, edited 1 time in total.
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Joined: May 12th, 2005, 1:57 am

September 21st, 2008, 2:42 pm #7

...essentially doubling the complexity of a PCP powerplant, while contributing little to performance, consistency, or accuracy that can't be achieved in a simpler way: adding volume to the air reservoir.

Steve
and it definitely improves the consistency of the gun. Is there seal issues occasionally, yes but it is not too often. Larry and Tims usft rifle is an excellent example of a self regulating action and it obviously works but there is still a place for a regulator in a gun today. Expecially one with a smaller resorvoir. Larry's simple simon rifle has a HUGE resorvoir and operated on a lower pressure system similar to the discovery I understand but a regulated discovery would definitely be cool. The only problem being that the resorvoir is rather small already and adding the regulator even a small one would make it even smaller.

My own homebuilt pcp was getting around 35-40 good shots before I got the regulator built and working and now it is getting over eighty from the same reservoir. OF course my valve was not maybe as efficient as it might be despite several different valve and valve body variations over a two year period. I am definitely glad to have the reg in the gun now as it is pretty consistent and gets more shots than I will probably ever need in a match. peace....

Pete Matos
865-363-9218
Matospeter@charter.net
Safe Journey Space Fans, Wherever you are....
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Joined: April 7th, 2007, 8:31 pm

September 21st, 2008, 2:50 pm #8

...increasing reservoir volume. How's that?

Plus, a regulated gun is inherently less efficient in converting air expenditure into muzzle energy. This is due to the pressure drop indroduced by the regulator.

Steve
translate into unwieldy guns. Remember the Drilling rifles. I think that design would make a nice template for an air rifle. Make the big barrels air reservoirs and keep the normal rifled barrel any caliber you want.

Also wondering if you introduced a regulator into an already designed system wouldn't that take up need air volume space. It would give regulation on the one hand, but take air volume away on the other maybe canceling out the benefits all together. Just a thought.
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Joined: May 12th, 2001, 1:29 pm

September 21st, 2008, 2:51 pm #9

and it definitely improves the consistency of the gun. Is there seal issues occasionally, yes but it is not too often. Larry and Tims usft rifle is an excellent example of a self regulating action and it obviously works but there is still a place for a regulator in a gun today. Expecially one with a smaller resorvoir. Larry's simple simon rifle has a HUGE resorvoir and operated on a lower pressure system similar to the discovery I understand but a regulated discovery would definitely be cool. The only problem being that the resorvoir is rather small already and adding the regulator even a small one would make it even smaller.

My own homebuilt pcp was getting around 35-40 good shots before I got the regulator built and working and now it is getting over eighty from the same reservoir. OF course my valve was not maybe as efficient as it might be despite several different valve and valve body variations over a two year period. I am definitely glad to have the reg in the gun now as it is pretty consistent and gets more shots than I will probably ever need in a match. peace....

Pete Matos
865-363-9218
Matospeter@charter.net
Safe Journey Space Fans, Wherever you are....
...I see a valve stem, spring, and several seals, at least three of which involve motion. Of all the components in an airgun, it's seals that accommodate motion that are the most likely to be maintenance issues. Also - good regulator designs will usually incorporate some means of adjusting the setpoint pressure without disassembly, which requires more moving parts and seals.

Meanwhile, your example of the USFT is a good one that proves my point that, given a large enough reservoir, self-regulation can deliver exactly as good consistency as can a regulator.

Steve
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Joined: May 12th, 2001, 1:29 pm

September 21st, 2008, 2:53 pm #10

translate into unwieldy guns. Remember the Drilling rifles. I think that design would make a nice template for an air rifle. Make the big barrels air reservoirs and keep the normal rifled barrel any caliber you want.

Also wondering if you introduced a regulator into an already designed system wouldn't that take up need air volume space. It would give regulation on the one hand, but take air volume away on the other maybe canceling out the benefits all together. Just a thought.


Steve
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