Author Topic: My Condor Builds (Read 24870 times))

rsterne · « **Reply #40 on:** March 20, 2014, 02:05:00 PM »

Did you find any advantage going over the boresize on the valve, ie .280 on a .257".... I know nothing about Condors, is there a stem in the way of the flow?.... If so, what is the diameter, and hence what is the remaining area at the smallest restriction?....

My .257 Hayabusa is running boresize porting right through.... The barrel port is 0.188 x 0.312", the transfer port is 1/4", the valve exhaust port is 1/4", and the valve throat is 0.281" with a 0.115" stem (0.256" equivalent)....

Bob

dyotat100 · « **Reply #41 on:** March 20, 2014, 02:10:55 PM »

I don't have a good place to shoot paper or the time.

I just let Tofazfou, knife maker, and 80 grit over on TAG do all the paper punching. Those are all my builds also.

I will contact the guy in Greece I built a 1:10 30" setup for and ask for some pics. He is shooting out to 400 yds.

dyotat100 · « **Reply #42 on:** March 20, 2014, 02:26:21 PM »

The valves I sell are .260" bore.

My .257 setup has a .280". At the time I was building it I was opening it up .010" at a time. I can't remember if it changed from .270" to .280". I just left it the way it is today. I need to put one of the new valves in my gun and see what it shoots.

I might be surprised and gain even more fps

rsterne · « **Reply #43 on:** March 20, 2014, 03:47:03 PM »

Is there a stem in the Condor valve?

Bob

Scott Endler · « **Reply #44 on:** March 20, 2014, 03:55:31 PM »

Quote from: rsterne on March 20, 2014, 02:05:00 PM

is there a stem in the way of the flow

the "top hat" is essentially a cross drilled thin walled tube once the poppet is opened. Also the whole tank is a huge, straight shot plenum with a funnel shape focusing the air flow right to to the poppet at the end of the tank. The smallest restriction could end up being the straight open end of the barrel.
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http://talontunes.com/shop/quick-change-top-hat/

Scott Endler · « **Reply #45 on:** March 20, 2014, 05:02:19 PM »

Here is a drawing showing the basic hammer/ breech slide/ top hat design of the AirForce.
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http://www.stealthresource.org/introduction.htm
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The only limit to the size of the poppet and top hat would be leaving enough material in the valve body to thread into the bottle. The id of the frame tube is 1.000 inches so this is the limit for the od of the hammer. There was a group buy for custom medium diameter 4,500 psi carbon bottles but I don't know how they intend to conveniently fill them to shoot that high.

Scott Endler · « **Reply #46 on:** March 20, 2014, 05:11:06 PM »

Quote from: dyotat100 on March 20, 2014, 02:26:21 PM

The valves I sell are .260" bore.

Is there an after market hpa bottle version of your valve that you sell. The Airforce bottle/ valve are over priced at $200.

rsterne · « **Reply #47 on:** March 20, 2014, 10:10:28 PM »

Thanks, I think I understand the airflow path now....

Bob

Scott Endler · « **Reply #48 on:** March 20, 2014, 11:08:37 PM »

That drawing makes it look like there is a spring inside the bore of the top hat but what he is really trying to show is that the tube is threaded on the end so the collar can screw up and down to set the max valve lift.

dyotat100 · « **Reply #49 on:** March 20, 2014, 11:13:19 PM »

Here are the differences between the stems. Stock condor on the left, my .25, .257, and .308.

Here is a stock condor stem inside my .257 valve and my .25 inside my .308 for a size comparison. A stock stem will fit inside my one off .25 valve that made 170 fpe with 89.5 gr in 24" barrel.

A stock condor valve is more than enough to shoot pellets but not enough for 70 gr slugs.

rsterne · « **Reply #50 on:** March 21, 2014, 01:28:20 AM »

What actually controls the airflow.... ie where is the seat that seals?.... I'm still having difficulty understanding that....

Bob

dyotat100 · « **Reply #51 on:** March 21, 2014, 04:47:55 AM »

Here is a old pick of my first .308 valve.

I'm out of town working and will be home Saturday and can get pic's of what ever you want then.

rsterne · « **Reply #52 on:** March 21, 2014, 12:25:42 PM »

OK, that changes things considerably.... What is the diameter of the hole in the valve body that contains the moving "top hat / valve stem".... and what is the diameter of the stem itself.... It looks like the hole in the valve body is the same size as the OD of the rear portion of the top hat.... That would mean that the throat is the same diameter as the OD of the smaller (rear) portion of the top hat and then you subtract the area of the stem, correct?.... I assume that area works out to larger than the ID of the top hat, but I'd like to see the numbers.... Once the top hat is inside the valve body, the area for flow is the ID of the valve body MINUS the stem and/or the web between the angled cross-holes, whichever is the largest at any given point....

In terms of lift, what are you allowing, at least 25% of the throat (seal) diameter?.... Less lift than that restricts the flow because of the "curtain height" effect.... Once poppet valves have a lift greater than 1/4 of the throat diameter, their flow rate can't increase because the limiting factor is the throat area instead of the curtain area....

Bob

Scott Endler · « **Reply #53 on:** March 21, 2014, 01:44:56 PM »

The stem that you see at the end of the top hat is buried in the poppet. The next thing the air sees when the valve opens are the two holes. Which, since his are on an angled surface, could have a combined area greater than the id of the top hat bore. The spring perch is trick also. This is beautiful work. The original factory valve is simply cross drilled. Though that looks like an old version factory valve. There is a new, high flow valve which has a different poppet and top hat. The other possible tight spot in the design could be the space between the inlet bore that the poppet moves back into, and the poppet od. But this looks to be more than generous also.

dyotat100 · « **Reply #54 on:** March 21, 2014, 01:56:28 PM »

Quote from: sendler2112 on March 21, 2014, 01:44:56 PM

The stem that you see at the end of the top hat is buried in the poppet. The next thing the air sees when the valve opens are the two holes. Which, since his are on an angled surface, could have a combined area greater than the id of the top hat bore. The spring perch is trick also. This is beautiful work. The original factory valve is simply cross drilled. Though that looks like an old version factory valve. There is a new, high flow valve which has a different poppet and top hat. The other possible tight spot in the design could be the space between the inlet bore that the poppet moves back into, and the poppet od. But this looks to be more than generous also.

You obviously don't know much about AF valves. All my valves are custom made. Not a modified valve. The valve in the picture is a .308 valve. It is a lot different from a AF valve.

Ok Bob here are some numbers for you

.25 valve
.310" opening
.100" stem
.375 seal
Stroke .115" (.135 on my one off valve)

.257/.308
.320" opening
.100" stem
.375" seal
Stroke .257 .115"
Stroke .308 .085"

I did a little porting on my .308 and it caused tank dump after 5 shots with 158 gr. It is now at .070" and still makes the same power and no more tank dump.

Scott Endler · « **Reply #55 on:** March 21, 2014, 02:05:39 PM »

Quote from: dyotat100 on March 21, 2014, 01:56:28 PM

All my valves are custom made. Not a modified valve. The valve in the picture is a .308 valve. It is a lot different from a AF valve.

Not sure where that came from...
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You are doing beautiful work. Want to sell me one?

rsterne · « **Reply #56 on:** March 21, 2014, 02:24:06 PM »

By "opening" do you mean the ID of the throat, downstream (forward) of the seat?.... or do you mean the ID of the hole through the top hat?.... Is the 0.375" "seal" the OD of the plastic poppet, or the ID of the throat where the seal occurs?.... Sorry for all the questions, but I've never been inside a Condor and want to understand them.... I would agree that the area of the angled ports are greater than the ID of the top hat.... Looking through the top hat you would "see" a restriction from the web between the holes, but by the flow "bending" a bit it wouldn't notice it.... The (thin part of the) stem still subtracts some area from the throat, however....

You certainly have plenty of lift on the .257 valve.... If the seat is 0.375" then you will continue to get increased flow up to a lift (stroke) of 0.094", although that may be a moot point as the ID of the air path is quite a bit less than that anyway.... so that 0.094" would be a maximum that would benefit you from a lift point of view.... However, increasing the lift further also increases the dwell of the valve, enabling more air to flow through it during the shot cycle....

I'm curious about your "tank dump" problem on the .308.... It sounds like a hammer bounce situation, re-opening the valve and causing the tank to drain once the pressure drops to a given level.... I had a similar situation on my first 9mm Disco Carbine when I tried a very light valve spring.... The shots went.... POP.... BANG.... B-BANG.... B-B-B-BURP.... BBRRAAAPPPPPPPPPPPPPPPPPP.... *LOL*.....

Bob

dyotat100 · « **Reply #57 on:** March 21, 2014, 03:00:40 PM »

Yes the opening is where the air comes in the valve then goes to the ports in the stem. I use 3 ports instead of the 2 AF uses for ease of manufacturing.

One of the main contributing factors to tank dump is the step in the barrel to bore size. With .25 you have a .250 bore and the barrel is .308".
so barrel is real thin and there is no step.

With .257 I machine the barrel to .374". I tried when I first built the .257 to use a .25 valve and I never got it to work. Even with 60 lb return spring the best I got was 1000 psi for the first shot(partial tank dump).

I then down sized the .308 valve a little and have never had a problem.

.308 barrel is .428" with .308 bore so the step is big also. But throw in heavy bullets and the tank dump gremlin is there. It took me some time and a lot of making parts and pieces to get where I an now.

There is some weird things that happened with these valves. If I take a .308 stem and open up the ports it will tank dump. On a .257 or .25 you can port all you want. .257/.308 valve has a 49 lb return spring. I'm sure I could use a smaller one on .257 but I got to a point where I was tired of experimenting. .25 valve will work with almost no spring.

I'm going to build a .308 with a .374" breech so there will be only .033" instead of .060". Should make it so I can shoot 200 gr bullets.

rsterne · « **Reply #58 on:** March 21, 2014, 04:18:40 PM »

You have a very different set of closing forces to work with than in a "conventional" valve where the end of the stem is exposed to atmospheric pressure and the area of the stem times the reservoir pressure provides the closing force.... In a gun with a 5/32" stem at 3000 psi, that works out to 57 lbs., plus another 7-10 lbs. for the spring.... In your case, if I understand it correctly, there is an O-ring sealing around the front of the top hat, so if that diameter is larger than the rear portion, then you have a net OPENING force.... Once the valve is open, the pressure on both ends of the top hat is essentially the same, so the opening force is that pressure times the area of the front stem of the top hat, while the closing force is that pressure times the area of the rear stem.... unless I'm not understanding it correctly.... That would sure explain the tendency to dump the tank....

Bob

rsterne · « **Reply #59 on:** March 26, 2014, 06:57:22 PM »

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My Condor Builds

Author Topic: My Condor Builds (Read 24870 times))