GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Tucobenedicto on September 15, 2016, 04:58:45 PM
-
I have read a post by Bigtinboat about a comparison between JDS regulators and Ninja and decided to try a ninja piston in my JDS regulator.
My hard tuned 850 airmagnum HPA converted was setted at 1700 psi and was capable of about 21fpe (.177 JSB heavy).
The belleville arrangement found in my JDS slammed on the Ninja piston gave to me 1450psi.well,the Ninja piston is a bit longer and engage the high pressure seal with less stroke.Added one Ninja silver shim the pressure raised at 1650 psi,added two silver shim and the pressure now is 1850 psi a bit high for me (980 fps).Tryed a Ninja red shim,but the reg stopped to work and gone full 3000 psi.
The original spring setup was )) ((( ))) (()) (( and seems a bit strange to me.
The question is : has anyone a suggestion about a better spring setup to work with?
It seems the regulator works in an area too much sensitive to shimming (one shim too low,two shim too high)
Any suggestion?
-
The nested (parallel) Belleville washers--those in the ))) arrangement--increase the spring rate but decrease the available travel as compared to a single thick washer. So as you add shims to increase the setpoint, the stack quickly runs out of travel (is squashed flat) and ceases to operate, sending the full pressure through.
The solution is to use thicker washers in a series arrangement )()()()()()(.
-
Thanks,i suspected the triple stack was not the best choice.Time to buy a bunch of new washers it seems,i have only 0,022 on hands.
-
I prefer to keep all sets of washers in a stack the same.... All singles, all pairs, or all triples.... If one set is stronger than the others, and you push the compression too close to flat, the weaker set can end up getting reversed and that damages them, they will no longer return to their original cup shape.... If you are not running them near their limit, you will end up with a somewhat "progressive" spring rate, which some feel is beneficial....
There are three commonly used Belleville washers in Ninja sized regulators (that includes JDS).... They are 0.022" thick (105 lbs flat load), 0.032" thick (260 lbs. flat load), and 0.047" (600 lbs. flat load).... There is some variation between brands, but basically a single 0.032" is stiffer than a pair of 0.022", and a single 0.047" is about the same as a pair of 0.032".... Given the choice, instead of using 0.022" arranged in pairs.... )) (( )) (( )) (( .... I would use 0.032" in series.... ) ( ) ( ) ( ) ( .... and then shim to get the pressure I need....
Bob
-
This make sense to me,it seems the guy who preset my regulator that way was out of thick washers.
My goal is a fine pressure adjustment,i want to keep my speed at no more of 950 fps or slightly under to increase shot counts.
My setup become too sensitive to hammer spring adjustment over 1800 psi and i was not able to hit my speed goal.
I will try 0,032 washer.
Thanks.
-
I am not able to find 0,032 bellevilles in my town,so i decided to try a "simmetric" arrangement with 0,022 washers.
I tryed a stack like this: )((()))((()))( and it gave me 1300 psi,so i added a Ninja red shim and now my pressure is 1810 psi/125 bar.
The first shot string:
293,4 m/s
293,7
293,7
293,4
294,1
294,5
295,2
294,1
It seems works great,and without pressure creep at full filling,i will try 0,032 belleville in the future for a finest adjustment,maybe ;)
For sure the Ninja piston works better than the JDS one like Bigtinboat sayed.
Never had this consistency before.Sorry for metric :D
-
I am not able to find 0,032 bellevilles in my town,so i decided to try a "simmetric" arrangement with 0,022 washers.
I tryed a stack like this: )((()))((()))( and it gave me 1300 psi,so i added a Ninja red shim and now my pressure is 1810 psi/125 bar.
The first shot string:
293,4 m/s
293,7
293,7
293,4
294,1
294,5
295,2
294,1
It seems works great,and without pressure creep at full filling,i will try 0,032 belleville in the future for a finest adjustment,maybe ;)
For sure the Ninja piston works better than the JDS one like Bigtinboat sayed.
Never had this consistency before.Sorry for metric :D
Just saw this - Welcome Fabio - glad you were able to duplicate the results with the Ninja piston. Seems a bunch of guys on the 850 Forum have the JDS, and just put up with the creep and slow recovery.
Nice having a single digit ES (your metric reading convert to 6fps) and best of all no CREEP
I get my bellevilles from ZORO, found them on ebay.
-
Hi Rob,i started from your input,i am a moderator on the 850 forum ;)
I posted my results there too.
Thanks.
-
It was Rob(Bigtinboat) Who helped me get the regs working well for our Warp and Flex, much tanks buddy. Night and day difference.
-
I saw some members of GTA in the 850 forum some time ago,Bigtinboat,rsterne,fivestar45 and others,i learned a lot of things from you guys,and from the members and the owner of the 850 forum (Roald) too.
Shooting and tuning are fun!
And i can improve my english too ;)
Thanks to all.
-
Fabio, the single Bellevilles that you have on each end of the stack will be driven completely flat in that arrangement, which may damage them.... they may never return to their full cup height.... This is not an issue as long as you make sure you keep them on the ends, and don't mix them up with the others.... or you will gradually ruin more and more Bellevilles and wonder why the pressure setpoint in your regulator is dropping each time you reassemble them in a different order.... Basically, once under tension, those end Bellevilles are becoming just a flat shim with maybe a little bit of preload effect from the cup....
Just something to be aware of....
Bob
-
Bob beat me to it :)
The ones on the end pretty much just become shims.
-
This is only a test with the washers i have on hand,i understended your imputs and i am waiting to put 0,032 belleville in my reg,stores in my zone want to sell me they in box of 500 >:( so i am searching a good on line shop here in europe.
Bob,the reason of the drop of pressure at first reassembly is i removed two silver shims to the setup,during regulators testing i prefer to reach my target pressure from low,just to see shims effect (and avoid to stress the 3K burst disk). I agree the two single washer are actually shims in this situation but at least now i have four triple washer working.
-
Finally finded a good source of industrial grade belleville washers in europe, SODEMANN industrifjedre a/s,in Denmark,not cheap but they have a wide catalog of springs of any shape and they ships small quantities.For Europe based folks a great source.
Following the guide of rsterne and nervoustrigger i ordered a bunch of 0,030 washers (and some spare hammer springs ;)).
Reading an old post by rsterne with a lot of graphs tryed an arrangement like this ))()()()()(( plus two ninja shims,one red (tick) and one silver (thin).Luckily i hitted my 1800 psi target with a couple of test.
I am pretty sure my regulator is now at his best and i can leave it alone for long time.
Thanks for the inputs.