JTS Aircuda Max .... TECHNICAL DATA & TUNING

[Motorhead]

* Please don't clutter this thread with random chatting ... stay on subject so ALL can utilize this resource effectively.  Thank you !
If others have information, data etc feel free to add it to this thread.

FOR CONVERSATION ON CONTENTS OF THIS THREAD ... Please openly converse here: [/b]https://www.gatewaytoairguns.org/GTA/index.php?topic=196353.msg156286643#msg156286643

Notes go with picture sequence best we can ...

Aircuda Max in .22 cal with a JTS 4-16x50 FFP scope ...

Trigger unit removed, side plate removed showing the internals.  * While it has the geometry of a 2 stage, it does not operate as one ... But a 1 stage with adjustable sear overlap and free play seeming like a 1st stage ( But is not )
AS VIEWED ... On far LEFT where spring sits on intermediate link, there is a 1.5mm set screw that adjusts Sear overlap.  The second 1.5mm screw on trigger blade ONLY adjusts the free travel before sear is contacted by trigger blade.

Barrel removed showing it THREADS into receiver with shroud mount also threaded acting as a jam nut to secure it firmly.  Metal baffles stack up against a semi-square air diverter at muzzle so air get into shroud.
* Make note the BRASS thimble "IS NOT Clockable " it to is threaded on. One must be VERY CAREFULL when R&R of barrel to make sure the Bridged transfer ends up being pointed down.  A Dot of paint can help here a bunch !

 Primary valve parts extracted ... Brass seat sits inside housing and poppet spring secured via a threaded cap ( You CAN change spring preload over a very broad range ) Plenum tube then screws on, followed by the Regulator tube where the Stainless Reg just slides in and rests on a machined shoulder. Gauge manifold fitting next for HPA and then primary air tube. 
* To adjust regulator you simply loosen the provided Bleed screw on left side below Plenum pressure gauge and dump all the air ... SLICK !!   Then unscrew the primary air tube forward of HPA gauge, insert a 3mm allen in adjustment bonnet of reg, adjust and reassemble ... Rinse and repeat until at wanted pressure. easy peezy 

Bottom view of the air tube / valve / hammer / trigger block.  To REMOVE upper receiver from lower .... Fill cap and barrel band off, Remove HST adjuster / spring and pull it out. Remove 2 screws on trigger assembly. Single screw
in rearmost hole behind trigger, 4 screws on forward valve block by plenum pressure guage, 2 screws in Magazine area ( 7 total ).  Have cocking lever out @ 1/2 way so the spring detent plunger & spring don't fly out !!  Lift the 2 half apart.  WaLa 

[Motorhead]

Doing some MODS .. or add-on was to get the .25 cal to power up w/o resorting to more hammer spring.  SO ... we added a small BRASS weight of @ 13 grams putting it in against hammer with spring on top ( Total hammer weight now @36 grams. )  Raised reg pressure to @ 155bar and we're making 50 ft lbs with JSB 25.4 kings @ 942 fpe and with 33.95 heavy @ 832 fps at 52.2 fpe maxed out.  Not too shabby for a carbine, not bad at all !

O' near forgot    How the .22 MAX shooting ... well detuned for some FT duty regulator at 100bar and set to the HST being right on the bell curve.  Crosman Dome 14.3 with 10 shots at 50 yards !!  Yea its a shooter !!

As a note of smoothing it up a tad, did remove hammer and scrubbed it down with 600 wet/dry.  The surface finish was very smooth but had bulk part pile micro frets here and there. All shined up smooth as glass.
Little bit of LIGHT machine oil on hammer, cocking pivots etc.  Gun was clean as heck, but not seeing much in factory lubrication present.

Out on the end of Shroud, when you remove the 1/2-20 LDC mount, you will see this threaded cover that has 2 spanner holes. It places the Baffles in compression when tightened having no rattles of looseness. Once srouds screwed on snug, stack in the baffles in correct orientation and snug down the retention cover, replace LDC mount and done. * It does screw on down @ 1/2" deep.

[Rohmpm]

Scott, it appears as if the plenum is its' own section? If so,  could a plenum section/longer plenum simply  be screwed on to increase volume? Adding the same length as a suppresor would maintain the lines.

[Motorhead]

By design correctly made ... longer or shorter.  Tho don't expect JTS to offer one.  These are quality economy air rifles first and foremost. As stated on other threads if an after market parts market develops it will be done within the private sector of air gun hobbyists as stated by Travis at JTS.

Scott, it appears as if the plenum is its' own section? If so,  could a plenum section/longer plenum simply  be screwed on to increase volume? Adding the same length as a suppresor would maintain the lines.

[Motorhead]

Another little snippet for those who may feel the "Need for Speed" and in that thought wonder what the Valve and transfer porting size is ?

BOTH the .22 & .25 are using the same valve housing and it has a massive @ .215" transfer path as does the receiver that matches up to it.
The brass Valve SEAT differs in only transfer exit size.  THROAT on each @ .236" ( 6mm ) using a Acetal looking poppet of @ .315" diameter with a .118" ( 3mm) stem.
IIRC the .22 valve body transfer passage exited at @ .165" where the .25 exited at @ .195" .... AGAIN into a .215" transfer path to the barrel.

Is there room to open things up further ?  Appears to be, tho for a .25 cal a .215" transfer is sufficient ++ and bore spec for a .22 cal, so no need there what so ever !!

[TroyHammer]

Another little snippet for those who may feel the "Need for Speed" and in that thought wonder what the Valve and transfer porting size is ?

BOTH the .22 & .25 are using the same valve housing and it has a massive @ .215" transfer path as does the receiver that matches up to it.
The brass Valve SEAT differs in only transfer exit size.  THROAT on each @ .236" ( 6mm ) using a Acetal looking poppet of @ .315" diameter with a .118" ( 3mm) stem.
IIRC the .22 valve body transfer passage exited at @ .165" where the .25 exited at @ .195" .... AGAIN into a .215" transfer path to the barrel.

Is there room to open things up further ?  Appears to be, tho for a .25 cal a .215" transfer is sufficient ++ and bore spec for a .22 cal, so no need there what so ever !!

The standard is limited to a smaller port due to the adjuster but that is very impressive on the max.

[Wayne52]

Looks like the barrel port is on that brass piece.

[Motorhead]

Looks like the barrel port is on that brass piece.

As travis called it "Thimble" ... yes its the two side by side ( Bridged ) slots.
*I suggested a change in this configuration to a full radial slot and 3-4 transfer holes such as XISICO did previous ... it would allow full barrel clocking and ease MAG gap adjustments.  We'll see

[Motorhead]

More MEASURED to confirm DATA on Air Tube Volume / Plenum Volume & @ Total

Has been factory stated the MAX carries approximately 220cc of air     So where is it all at and what of it can we actually use while being on the regulator ?

Running the numbers on a CC volume calculator we get: 
HPA main tank @ 186cc
Reg Manifold & Fill manifold space @ 8.84cc
* Total HPA storage @ 194.84cc

Plenum numbers we get @ 21.1 cc
Valve body / area above poppet @ 4cc
* Total plenum @ 25.1cc

My numbers confirm @ 219.94cc min ( likely a tad more in valve body ...  so ) ...    Yes indeed there is @ 220 cc of air on board.

Scott S

[Wayne52]

Looks like the barrel port is on that brass piece.

As travis called it "Thimble" ... yes its the two side by side ( Bridged ) slots.
*I suggested a change in this configuration to a full radial slot and 3-4 transfer holes such as XISICO did previous ... it would allow full barrel clocking and ease MAG gap adjustments.  We'll see

That's a better idea I think for the ports, I'm really not a fan of the barrel being choked either, in my opinion that's a lame way of making different pellets shoot good, if the pellets are good pellets they should shoot good from an unchoked barrel.  Slower twist rate should work better with pellets as well.

[Hajimoto]

Not that my confirmation is required for your data to be relevant but thank you Scott for posting your findings as they mirror mine exactly. I will try my best to post any and all technical finding here in this thread in an attempt to consolidate the data.
I am thoroughly impressed with the consistency of these PCP's and your data does nothing but elevate my positive impression of the workmanship on these units.


If the factory continues to build the future units to these specs, there will be very little for end-users to complain about.

[oldpro]

 Short stiff spring all else bone stock. Ill tune it to 3 power levels with same spring.

Created: 16/02/22 03:19 PM
Description: Airacuda MAX 25
Notes 1: Cuda MAX
Notes 2: heavy short spring
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 25.00
Temp: 69 °F
BP: 1012.00 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
46    838      38.99    20.95   
45    838      38.99    20.95   
44    842      39.36    21.05   
43    845      39.64    21.12   
42    846      39.74    21.15   
41    847      39.83    21.17   
40    847      39.83    21.17   
39    846      39.74    21.15   
38    848      39.93    21.20   
37    840      39.18    21.00   
36    842      39.36    21.05   
35    839      39.08    20.98   
34    841      39.27    21.02   
33    845      39.64    21.12   
32    839      39.08    20.98   
31    847      39.83    21.17   
30    843      39.46    21.08   
29    842      39.36    21.05   
28    840      39.18    21.00   
27    842      39.36    21.05   
26    840      39.18    21.00   
25    848      39.93    21.20   
24    845      39.64    21.12   
23    839      39.08    20.98   
22    840      39.18    21.00   
21    840      39.18    21.00   
20    835      38.71    20.88   
19    846      39.74    21.15   
18    842      39.36    21.05   
17    845      39.64    21.12   
16    841      39.27    21.02   
15    839      39.08    20.98   
14    843      39.46    21.08   
13    839      39.08    20.98   
12    845      39.64    21.12   
11    838      38.99    20.95   
10    847      39.83    21.17   
9     841      39.27    21.02   
8     840      39.18    21.00   
7     834      38.62    20.85   
6     844      39.55    21.10   
5     844      39.55    21.10   
4     841      39.27    21.02   
3     841      39.27    21.02   
2     842      39.36    21.05   
1     837      38.90    20.92   
Average: 842.0 FPS
SD: 3.4 FPS
Min: 834 FPS
Max: 848 FPS
Spread: 14 FPS
Shot/sec: 0.1
True MV: 842 FPS
Group Size (in): 0.00

[BigMike1]

Short stiff spring all else bone stock. Ill tune it to 3 power levels with same spring.

Created: 16/02/22 03:19 PM
Description: Airacuda MAX 25
Notes 1: Cuda MAX
Notes 2: heavy short spring
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 25.00
Temp: 69 °F
BP: 1012.00 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
46    838      38.99    20.95   
45    838      38.99    20.95   
44    842      39.36    21.05   
43    845      39.64    21.12   
42    846      39.74    21.15   
41    847      39.83    21.17   
40    847      39.83    21.17   
39    846      39.74    21.15   
38    848      39.93    21.20   
37    840      39.18    21.00   
36    842      39.36    21.05   
35    839      39.08    20.98   
34    841      39.27    21.02   
33    845      39.64    21.12   
32    839      39.08    20.98   
31    847      39.83    21.17   
30    843      39.46    21.08   
29    842      39.36    21.05   
28    840      39.18    21.00   
27    842      39.36    21.05   
26    840      39.18    21.00   
25    848      39.93    21.20   
24    845      39.64    21.12   
23    839      39.08    20.98   
22    840      39.18    21.00   
21    840      39.18    21.00   
20    835      38.71    20.88   
19    846      39.74    21.15   
18    842      39.36    21.05   
17    845      39.64    21.12   
16    841      39.27    21.02   
15    839      39.08    20.98   
14    843      39.46    21.08   
13    839      39.08    20.98   
12    845      39.64    21.12   
11    838      38.99    20.95   
10    847      39.83    21.17   
9     841      39.27    21.02   
8     840      39.18    21.00   
7     834      38.62    20.85   
6     844      39.55    21.10   
5     844      39.55    21.10   
4     841      39.27    21.02   
3     841      39.27    21.02   
2     842      39.36    21.05   
1     837      38.90    20.92   
Average: 842.0 FPS
SD: 3.4 FPS
Min: 834 FPS
Max: 848 FPS
Spread: 14 FPS
Shot/sec: 0.1
True MV: 842 FPS
Group Size (in): 0.00

WOW !!!

[Jr007]

Short stiff spring all else bone stock. Ill tune it to 3 power levels with same spring.

Created: 16/02/22 03:19 PM
Description: Airacuda MAX 25
Notes 1: Cuda MAX
Notes 2: heavy short spring
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 25.00
Temp: 69 °F
BP: 1012.00 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
46    838      38.99    20.95   
45    838      38.99    20.95   
44    842      39.36    21.05   
43    845      39.64    21.12   
42    846      39.74    21.15   
41    847      39.83    21.17   
40    847      39.83    21.17   
39    846      39.74    21.15   
38    848      39.93    21.20   
37    840      39.18    21.00   
36    842      39.36    21.05   
35    839      39.08    20.98   
34    841      39.27    21.02   
33    845      39.64    21.12   
32    839      39.08    20.98   
31    847      39.83    21.17   
30    843      39.46    21.08   
29    842      39.36    21.05   
28    840      39.18    21.00   
27    842      39.36    21.05   
26    840      39.18    21.00   
25    848      39.93    21.20   
24    845      39.64    21.12   
23    839      39.08    20.98   
22    840      39.18    21.00   
21    840      39.18    21.00   
20    835      38.71    20.88   
19    846      39.74    21.15   
18    842      39.36    21.05   
17    845      39.64    21.12   
16    841      39.27    21.02   
15    839      39.08    20.98   
14    843      39.46    21.08   
13    839      39.08    20.98   
12    845      39.64    21.12   
11    838      38.99    20.95   
10    847      39.83    21.17   
9     841      39.27    21.02   
8     840      39.18    21.00   
7     834      38.62    20.85   
6     844      39.55    21.10   
5     844      39.55    21.10   
4     841      39.27    21.02   
3     841      39.27    21.02   
2     842      39.36    21.05   
1     837      38.90    20.92   
Average: 842.0 FPS
SD: 3.4 FPS
Min: 834 FPS
Max: 848 FPS
Spread: 14 FPS
Shot/sec: 0.1
True MV: 842 FPS
Group Size (in): 0.00

So what the starting psi and end psi on the tank.

[oldpro]

 Here you go.


2022-02-16 | 22:44:01 mtn
avg FPE/cuin per shot
1.68
avg bar-cc/FPE per shot
9.8
avg FPE per shot
40
avg PSI used per shot
30
For your records when printing:

Airgun
Barrel length
Type of pellet
Notes


Prints entire screen in black and white
PCP Air Efficiency Calculator
PSI before first shot
3400

Enter an integer from 1000 to 5000
PSI after last shot
2000

Enter an integer from 200 to 5000 which is less than the first PSI
Gun tank volume in cc
186

Enter an integer from 1 to 20000
Pellet weight
25.4

Enter an integer or decimal number from 2.1 to 1000
Total number of shots
46

Enter an integer from 1 to 500
Average FPS for all the shots
842

Enter an integer from 100 to 1500

 
Want to keep some of your previous data? Don't clear.
Just change the other fields and click Calculate again.

[casino7095]

Not that my confirmation is required for your data to be relevant but thank you Scott for posting your findings as they mirror mine exactly. I will try my best to post any and all technical finding here in this thread in an attempt to consolidate the data.
I am thoroughly impressed with the consistency of these PCP's and your data does nothing but elevate my positive impression of the workmanship on these units.


If the factory continues to build the future units to these specs, there will be very little for end-users to complain about.

Look forward to seeing your impression of the workmanship.

[oldpro]

Airacuda Max .22 SSSpring shooting in warehouse at 40F all 55 shots at 30 yards can be covered with nickel


Created: 18/02/22 11:27 AM
Description: JTS Cuda .22
Notes 1: Heavy spring
Notes 2: 3500-1900
Distance to Chrono(FT): 3.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 18.00
Temp: 45 °F
BP: 1026.00 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
55    919      33.76    16.54   
54    922      33.98    16.60   
53    921      33.91    16.58   
52    924      34.13    16.63   
51    920      33.83    16.56   
50    920      33.83    16.56   
49    919      33.76    16.54   
48    919      33.76    16.54   
47    921      33.91    16.58   
46    921      33.91    16.58   
45    921      33.91    16.58   
44    920      33.83    16.56   
43    924      34.13    16.63   
42    923      34.06    16.61   
41    921      33.91    16.58   
40    923      34.06    16.61   
39    919      33.76    16.54   
38    924      34.13    16.63   
37    921      33.91    16.58   
36    921      33.91    16.58   
35    921      33.91    16.58   
34    921      33.91    16.58   
33    921      33.91    16.58   
32    920      33.83    16.56   
31    923      34.06    16.61   
30    921      33.91    16.58   
29    919      33.76    16.54   
28    921      33.91    16.58   
27    921      33.91    16.58   
26    921      33.91    16.58   
25    928      34.43    16.70   
24    921      33.91    16.58   
23    924      34.13    16.63   
22    924      34.13    16.63   
21    923      34.06    16.61   
20    927      34.35    16.69   
19    926      34.28    16.67   
18    923      34.06    16.61   
17    926      34.28    16.67   
16    922      33.98    16.60   
15    929      34.50    16.72   
14    925      34.20    16.65   
13    924      34.13    16.63   
12    923      34.06    16.61   
11    924      34.13    16.63   
10    923      34.06    16.61   
9     919      33.76    16.54   
8     920      33.83    16.56   
7     927      34.35    16.69   
6     923      34.06    16.61   
5     921      33.91    16.58   
4     925      34.20    16.65   
3     926      34.28    16.67   
2     928      34.43    16.70   
1     928      34.43    16.70   
Average: 922.6 FPS
SD: 2.7 FPS
Min: 919 FPS
Max: 929 FPS
Spread: 10 FPS
Shot/sec: 0.0
True MV: 923 FPS
Group Size (in): 0.00

[oldpro]

[oldpro]

 Another tuning method that works on both the Standard and MAX is the valve return spring has a long threaded retainer that can be adjusted for more power or a tighter ES.

[Firewalker]

Airacuda Max .22 SSSpring shooting in warehouse at 40F all 55 shots at 30 yards can be covered with nickel


Created: 18/02/22 11:27 AM
Description: JTS Cuda .22
Notes 1: Heavy spring
Notes 2: 3500-1900
Distance to Chrono(FT): 3.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 18.00
Temp: 45 °F
BP: 1026.00 inHg
Altitude: 0.00
#          FPS   FT-LBS       PF
55    919      33.76    16.54   
54    922      33.98    16.60   
53    921      33.91    16.58   
52    924      34.13    16.63   
51    920      33.83    16.56   
50    920      33.83    16.56   
49    919      33.76    16.54   
48    919      33.76    16.54   
47    921      33.91    16.58   
46    921      33.91    16.58   
45    921      33.91    16.58   
44    920      33.83    16.56   
43    924      34.13    16.63   
42    923      34.06    16.61   
41    921      33.91    16.58   
40    923      34.06    16.61   
39    919      33.76    16.54   
38    924      34.13    16.63   
37    921      33.91    16.58   
36    921      33.91    16.58   
35    921      33.91    16.58   
34    921      33.91    16.58   
33    921      33.91    16.58   
32    920      33.83    16.56   
31    923      34.06    16.61   
30    921      33.91    16.58   
29    919      33.76    16.54   
28    921      33.91    16.58   
27    921      33.91    16.58   
26    921      33.91    16.58   
25    928      34.43    16.70   
24    921      33.91    16.58   
23    924      34.13    16.63   
22    924      34.13    16.63   
21    923      34.06    16.61   
20    927      34.35    16.69   
19    926      34.28    16.67   
18    923      34.06    16.61   
17    926      34.28    16.67   
16    922      33.98    16.60   
15    929      34.50    16.72   
14    925      34.20    16.65   
13    924      34.13    16.63   
12    923      34.06    16.61   
11    924      34.13    16.63   
10    923      34.06    16.61   
9     919      33.76    16.54   
8     920      33.83    16.56   
7     927      34.35    16.69   
6     923      34.06    16.61   
5     921      33.91    16.58   
4     925      34.20    16.65   
3     926      34.28    16.67   
2     928      34.43    16.70   
1     928      34.43    16.70   
Average: 922.6 FPS
SD: 2.7 FPS
Min: 919 FPS
Max: 929 FPS
Spread: 10 FPS
Shot/sec: 0.0
True MV: 923 FPS
Group Size (in): 0.00

JEEPERS!

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