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Author Topic: Building a better balanced valve  (Read 1379 times)

rsterne

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Re: Building a better balanced valve
« Reply #15 on: August 02, 2017, 10:14:55 PM »
Yep, sure does.... Any idea what the plateau (maximum) velocities are with the two valves at 2Ksi, and how much difference the hammer strike to achieve that?.... It would seem reasonable that if the ports are the same, the max. velocity would be as well.... but of course the efficiency may not be....

I'm still trying to wrap my brain around the operating conditions, relative to the plateau, knee, and downslope, with the tunes used.... The fact you are getting higher efficiency at higher power just blows me away....  8)

Bob
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Christopher

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Re: Building a better balanced valve
« Reply #16 on: August 03, 2017, 03:07:37 AM »
I think that another interesting test would be to put the conventional valve back in, then crank up the hammer spring until you reach the same velocity as the ART/Sikes valve. Keep the set point the same of course, then we would get an idea of what the air consumption would be at equal power levels. Just saying...... :)  And of course,  MAXIUMUM  POWER (said in a deep, echoing, slightly digitized voice) ;D for each valve.

Chris

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rsterne

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Re: Building a better balanced valve
« Reply #17 on: August 03, 2017, 08:43:56 AM »
I agree, Chris.... the more data the better....

Bob
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Motorhead

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Re: Building a better balanced valve
« Reply #18 on: August 03, 2017, 09:57:50 AM »
Not sure this thread being the right place ... but having been working with Travis some on his "Cobra" variation valve tech I have some loose data to share.

Had designed and retrofitted the valve on the RAW TM-1000 FT gun a few months ago with "Cobra" style parts and been very happy with the snappier shot cycle and air savings found. 
In owning this gun a few years now have done extensive R&D in making it a better gun than delivered, been successful in this quest by applying SSG device, Lightened hammer, Different port sizing & such mods many have been fooling with of late.

Prior to "Cobra" mods the REGULATION pressure required to get a solid 19 ft lbs in a tight Sub 10 fps ES required @ 125/130 BAR pressure within valve.
Hammer weight able to be kept light, but heavier hammer spring tension required to fire the hammer VERY FAST at the poppet ... actually this worked excellent ! giving a very fast lock time and very little cyclic vibration.
* Enter the "COBRA" mod .... For these past few months been shooting the RAW set up as above operating at 128BAR without issue but a bit of reg creep noted and a shift in velocity in 1st shot of after an hour of more of non use.   ??? ??? ???  LIGHT BULB MOMENT that had me do a test that frankly had never been done while doing the "Cobra" R&D with Travis.

Knowing Regulator being set at 128 bar bled off pressure in the guns 400cc bottle to @ 80 bar, hooked up my Test Grade pressure gauge to my filler from HPA tank and started doing CHRONY shots as pressure was raised in 10 bar increments.
** This keeping the hammer & spring tension fixed at the power level gun had been at with 128 bar JSB 13.6 grain .20 cal @ 810 fps
At @ 80 bar velocity was mid 600's, at 90 bar low 800's and at 100bar 860's !!! WHAT THE HECK  :o :o
As we went past 100 bar to 110 to 120 then 130 the velocity fell back down settling out at @ 810 fps once regulator set point was active.

BOY WAS THIS FUBBARED ... so telling that as set up with the "Cobra" tech parts we were no longer operating near the bell curve optimal set pressure for the hammer weight and strike energy ... WHOA way the heck off !!!

So ... pulled the regulator placing it into the test / set fixture reducing output to a touch over 100 bar, installed back into rifle then confirming velocity of @ 860 fps.
Ok that will allow me to back off on hammer spring energy and being done ... settled back in at @ 810 fps velocity.
* Gun now cocks far easier, still has IMO wicked fast lock time yet now is so stable in velocity were seeing typically +/- 4 fps or less ES figures & shows virtually no set point creep velocity swings cold shot or after sitting as it had done previous.

We know that when a regulated gun is tuned near the knee that slightly lower of higher pressure within plenum has the lest effect on velocity swings  :)
Where I'm going here needing to be long winded in explanation is the EFFECT the "Cobra" valve mods had on the valves closing cycle and the major shift it made in required pressure to operate efficiently & effectively.

It is of MY OPINION that in a conventional valve, to get efficiency we need the higher pressure so the valve is able to be cracked yet because of the high pressure is willing to close fast too.  We want that SNAP shot cycle. 
Using lower pressure can work, but typically in my experience comes at the expense of excessive valve dwell and more air used per shot.

* The "Cobra" mod valve parts which vastly accelerate the valves closing speed is felt the major contributor to these results found above ... It did not take 128 bar to make the power required, only 100 bar. Because of the accelerated closing cycle / reduced dwell we fell into a tune parameter never experienced or documented best i know before.


Hope others find some interest in this data ...
Scott
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Scott

oldpro

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Re: Building a better balanced valve
« Reply #19 on: August 03, 2017, 11:00:30 AM »
  The Dwell of a valve consists of two parts 1.Lift time to max height 2. closing time to seated. What this valve does better than other valves and why its so efficient is #2 its clamping rate or closing time is far superior so If we build a high breathing valve with large lift we can control that with a super fast clamping rate. What this means is high power with the least amount of dwell time so less waisted air and a quieter report. There are parts of the technology we still dont all agree on how it works(Bob/me/Lloyd and Scott) because we frankly dont know yet how it works its sort of a mini mystery but we do know how to adjust the mystery area to get what we need. As I get closer to production I hope I have a full understanding of this simple but mysterious valves inner workings.
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oldpro

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Re: Building a better balanced valve
« Reply #20 on: August 03, 2017, 01:55:14 PM »
 Ran unregulated string and added 1/4 turn to help ramp it up to open at higher pressure. It was filled to 3k and for comparison it was at 2k (previous reg set point) at shot 27. No fine tuning what so ever just raw data. As you can see it will make a bell curve and if Hammer strike and fill pressures were adjusted you would have most excellent results.

Created: 08/03/17 01:03 PM
Description: Warp .25
Notes 1: 3k to 1400psi 1/4 turn in on HD
Notes 2: 15" barrel unregulated
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 34.00
Temp: 90 °F
BP: 30.02 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
45    708      37.85    24.07   
44    726      39.80    24.68   
43    735      40.79    24.99   
42    752      42.70    25.57   
41    759      43.50    25.81   
40    769      44.65    26.15   
39    781      46.06    26.55   
38    791      47.24    26.89   
37    799      48.20    27.17   
36    806      49.05    27.40   
35    816      50.28    27.74   
34    822      51.02    27.95   
33    827      51.64    28.12   
32    838      53.03    28.49   
31    836      52.77    28.42   
30    841      53.41    28.59   
29    848      54.30    28.83   
28    859      55.72    29.21   
27    864      56.37    29.38   
26    868      56.89    29.51   
25    867      56.76    29.48   
24    864      56.37    29.38   
23    864      56.37    29.38   
22    864      56.37    29.38   
21    859      55.72    29.21   
20    856      55.33    29.10   
19    853      54.94    29.00   
18    841      53.41    28.59   
17    837      52.90    28.46   
16    826      51.52    28.08   
15    823      51.14    27.98   
14    813      49.91    27.64   
13    800      48.33    27.20   
12    805      48.93    27.37   
11    785      46.53    26.69   
10    770      44.77    26.18   
9     773      45.12    26.28   
8     768      44.54    26.11   
7     753      42.81    25.60   
6     751      42.59    25.53   
5     750      42.47    25.50   
4     738      41.13    25.09   
3     727      39.91    24.72   
2     730      40.24    24.82   
1     717      38.82    24.38   
Average: 801.8 FPS
SD: 49.0 FPS
Min: 708 FPS
Max: 868 FPS
Spread: 160 FPS
Shot/sec: 0.1
True MV: 802 FPS
Group Size (in): 0.00
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oldpro

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Re: Building a better balanced valve
« Reply #21 on: August 03, 2017, 01:55:38 PM »
 Ok power tune from 3K fill same gun warp .25 15" barrel ART/Sikes valve. This was 3 turns in from previous test. There is 3 more turns till spring bind and if I fill to 3200 I can easy hit 70fpe from this little 15" barrel

Created: 08/03/17 01:41 PM
Description: 3k to 2500
Notes 1: unregulated max power string
Notes 2:
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 34.00
Temp: 91 °F
BP: 30.02 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
12    890      59.81    30.26   
11    895      60.48    30.43   
10    903      61.57    30.70   
9     910      62.53    30.94   
8     915      63.22    31.11   
7     919      63.77    31.25   
6     929      65.17    31.59   
5     928      65.03    31.55   
4     927      64.89    31.52   
3     916      63.36    31.14   
2     926      64.75    31.48   
1     936      66.15    31.82   
Average: 916.2 FPS
SD: 14.4 FPS
Min: 890 FPS
Max: 936 FPS
Spread: 46 FPS
Shot/sec: 0.1
True MV: 916 FPS
Group Size (in): 0.00
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Christopher

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Re: Building a better balanced valve
« Reply #22 on: August 03, 2017, 05:09:40 PM »
Thanks Travis for the data, keep it coming. This valve is amazing. Looks like you've found a nice balance (pun intended) between adjustability and the ease of balanced valves. I tip my hat to ya sir.

Chris
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bnowlin

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Re: Building a better balanced valve
« Reply #23 on: August 03, 2017, 06:46:07 PM »
Ok power tune from 3K fill same gun warp .25 15" barrel ART/Sikes valve. This was 3 turns in from previous test. There is 3 more turns till spring bind and if I fill to 3200 I can easy hit 70fpe from this little 15" barrel

Created: 08/03/17 01:41 PM
Description: 3k to 2500
Notes 1: unregulated max power string
Notes 2:
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 34.00
Temp: 91 °F
BP: 30.02 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
12    890      59.81    30.26   
11    895      60.48    30.43   
10    903      61.57    30.70   
9     910      62.53    30.94   
8     915      63.22    31.11   
7     919      63.77    31.25   
6     929      65.17    31.59   
5     928      65.03    31.55   
4     927      64.89    31.52   
3     916      63.36    31.14   
2     926      64.75    31.48   
1     936      66.15    31.82   
Average: 916.2 FPS
SD: 14.4 FPS
Min: 890 FPS
Max: 936 FPS
Spread: 46 FPS
Shot/sec: 0.1
True MV: 916 FPS
Group Size (in): 0.00

Travis how is that compared to a 23 inch barrel and a Cobra vs the new one
Bobn

rsterne

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Re: Building a better balanced valve
« Reply #24 on: August 03, 2017, 07:23:32 PM »
65 FPE from a 15" barrel is pretty stout, IMO....

Bob
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oldpro

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Re: Building a better balanced valve
« Reply #25 on: August 03, 2017, 08:40:23 PM »
The barrel port is only .185 and the short barrel are not conducive to making big power but the valve is making 10fpe more power than original valve at same power and still more efficient...No lose situation.
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Alan

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Re: Building a better balanced valve
« Reply #26 on: August 04, 2017, 03:06:02 AM »
Okay! Okay! My appetite is whetted! So when can I buy one? And how much?
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oldpro

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Re: Building a better balanced valve
« Reply #27 on: August 04, 2017, 12:10:29 PM »
   Pulling gun apart today and sending off drawings and valve to Matt but I did have time to run a string with light hammer and Regulator

Created: 08/04/17 11:39 AM
Description: Warp .25
Notes 1: ART/Sikes 15" barrel
Notes 2: 2900/2000 13ci tank
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 25.40
Temp: 79 °F
BP: 30.04 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
27    897      45.39    22.78   
26    899      45.59    22.83   
25    900      45.69    22.86   
24    905      46.20    22.99   
23    898      45.49    22.81   
22    899      45.59    22.83   
21    901      45.79    22.89   
20    908      46.51    23.06   
19    900      45.69    22.86   
18    901      45.79    22.89   
17    900      45.69    22.86   
16    905      46.20    22.99   
15    898      45.49    22.81   
14    905      46.20    22.99   
13    901      45.79    22.89   
12    904      46.10    22.96   
11    904      46.10    22.96   
10    904      46.10    22.96   
9     905      46.20    22.99   
8     902      45.89    22.91   
7     908      46.51    23.06   
6     900      45.69    22.86   
5     908      46.51    23.06   
4     907      46.40    23.04   
3     905      46.20    22.99   
2     903      46.00    22.94   
1     899      45.59    22.83   
Average: 902.4 FPS
SD: 3.3 FPS
Min: 897 FPS
Max: 908 FPS
Spread: 11 FPS
Shot/sec: 0.0
True MV: 903 FPS
Group Size (in): 0.00
« Last Edit: August 04, 2017, 12:55:01 PM by oldpro »
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rsterne

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Re: Building a better balanced valve
« Reply #28 on: August 04, 2017, 12:43:29 PM »
Is it really a 16 CI tank (262 cc)?.... Pressure drop was 900 psi (62 bar) x 16 = 993 CI total.... 27 shots at 45.9 FPE avg. = 1240 FPE total.... That works out to 1.25 FPE/CI.... Nice tight string at 11 fps ES....

Bob
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oldpro

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Re: Building a better balanced valve
« Reply #29 on: August 04, 2017, 12:54:22 PM »
 Sorry 13ci ninja tank ,good catch Bob I fixed post.
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