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Thread: Regulator Build

  1. #1
    Marksman

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    Default Regulator Build

    After 4 tins of JSB pellets through my Artemis PR900w the time has come to regulate the rifle.

    Owning the cheapest PCP on the market says a few things, one of them is my budget is small, very small.
    So when it comes to regulating the rifle, there isn't much of a choice other than building my own one.
    I did a lot of research on o-ring design and regulators and the Robert Lane videos on Youtube was very helpful.
    When I was happy with my concept, I got the springs and tweaked the design around them.





    Here is the 2 springs I got.
    My calculations showed that I needed around 600N of Spring force to acquire an average regulated pressure of 9Mpa or 90Bar over the 200Bar-80Bar fill pressure range.
    so I got a 350N/mm and a 270N/mm spring of equal length and OD.

    Here is a section photo of the design:


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  2. #2
    Marksman

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    While waiting for the o-rings to be delivered I got to work on the "body of the regulator".
    It is advisable to work according to the hole based system: where you manufacture the parts with tight tolerance holes first, before you manufacture the shafts or in this case the piston.
    The reason being that it is a lot easier to get a shaft on to tolerance- so you basically make the shaft/piston to fit the hole.








    I opted for M8x1 thread for the adjuster screw because it is a standard size tap and allows for relatively fine adjustment.
    A quarter turn would theoretically yield a 70N-90N change in the lockout force and more or less a 10Bar adjustment on the regulated pressure.
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  3. #3
    Marksman

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    If you ever thinking of making more ,please... i will be interested of purchasing one

    Pieter
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  4. #4
    Marksman
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    Hi Ryno hoop ons sien jou by die club shoot
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  5. #5
    Marksman

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    Today I finished all the manufacturing on the regulator.
    Because I had a CAD model of my design it was fairly easy to make everything come together.
    I started off with the piston, I was concerned about the 4.1mm shank being to long and thin to cut.
    I managed to get it right 1st time with a 0.3mm depth of cut without a running centre.
    I the drilled the 2.5mm hole running through.




    The o-ring groove depth is determined by the actual diameter of the bore in which the piston runs, that is why you cut and polish that part first.
    After the piston is parted off, I used a deburring tool to create the "knifes edge" at the back that locks the regulator up.
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  6. #6
    Marksman

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    The next step was to manufacture the adjuster/lockup screw.
    I have to admit : this simple part I had to twice to get right.
    When I cut the threads the 1st time it was a bit to loose and I was afraid it would wiggle out when there is movement on the piston.





    I drilled a 6mm hole 3/4 way through and parted it off.
    I Then turned a small piece of nylon to fit the hole.
    I hammered it in and sanded it flat and square to the axis.

    The manufacturing is now complete, and I am waiting for the correct o-rings to be delivered.
    I will speak about the o-rings tomorrow after I collected them and assembled everything.


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  7. #7
    REP: Outdoor Pitstop
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    [/QUOTE]

    Wow, that's pride in your work right there. Lekker.
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  8. #8
    Sharp Shooter

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    Quote Originally Posted by ryno smith View Post
    The next step was to manufacture the adjuster/lockup screw.
    I have to admit : this simple part I had to twice to get right.
    When I cut the threads the 1st time it was a bit to loose and I was afraid it would wiggle out when there is movement on the piston.





    I drilled a 6mm hole 3/4 way through and parted it off.
    I Then turned a small piece of nylon to fit the hole.
    I hammered it in and sanded it flat and square to the axis.

    The manufacturing is now complete, and I am waiting for the correct o-rings to be delivered.
    I will speak about the o-rings tomorrow after I collected them and assembled everything.


    Ryno, great work ......

    See how you get on, but from when I still fiddled ........

    Having a very sharp edge on the sealing piston was not ideal over the long run. It would eventually "eat" into your seating material and then start to cause problems. A very smooth small radius edge I found worked best.

    The seat material also need to be hard enough to stand up to the wear and soft enough to allow for sealing.
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  9. #9
    Marksman

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    Thank you for the advice Wannebe!
    What you say makes sense, and I will sand it down lightly to just break that sharp edge and give it a rounded shape.
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  10. #10
    REP: Froggy Custom Silencers

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    Well done Ryno! Thanks for sharing.
    Ek hou duim vas vir jou dat hy mooi gaan werk.
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  11. #11
    Protea Benchrest (Air) Team '15/'17

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    Quote Originally Posted by Wannebe View Post
    Ryno, great work ......

    See how you get on, but from when I still fiddled ........

    Having a very sharp edge on the sealing piston was not ideal over the long run. It would eventually "eat" into your seating material and then start to cause problems. A very smooth small radius edge I found worked best.

    The seat material also need to be hard enough to stand up to the wear and soft enough to allow for sealing.
    Agree 100% with Albert. I also tried to "improve"' my EV2 reg by "sharpening" the edge - worked perfect for the first couple of shots and then it started to creep. You need a balance in terms hardness of the seat material, piston surface area and max force to press it shut. Your spring stiffness only allow for a specific optimum regulated pressure to get a quick shut off that does not creep. I assume thats why Steyr use bevel washers and spacers to get to that optimum pressure value and quick shut off with minimal creep?

    Sharp edge cut into seat material - which is a no, no.
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  12. #12
    Marksman

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    On Friday I collected the o-rings and on the last minute I decided to turn a new housing.
    On version 1 I used a 2 flute end mill the tailstock to "drill" the bore of the regulator.
    I didn't take a big cut with it, but after polishing I noticed a small helical groove running down, similar to one you sometimes get when drilling.
    The fear of air leaking past the piston seal and out of the atmospheric breathe hole was unbearable and I just had to do another one.
    On Version 2 I used a boring-bar to bore the hole. (I know I should have done it the first time)
    I also added a small groove at the back to which I attached an electrical wire to easily remove the regulator.

    The regulator was now ready to be installed.
    I calculated that I need about 3CC of air at 90 bar to accelerate the pellet to 16J (12FPE) over the length of the barrel.
    I did not trust the result of the calculation but at least it verified the figures Robert Lane gave in his videos.
    He recommended 9cc at 90 bar for 12FPE. I knew I needed somewhere between 3CC and 9CC of air at 90 bar to obtain 12FPE
    So I felt somewhat comfortable drilling the breathe hole.

    Back to the O-rings.
    After a bit of research, I found that O-rings with a hardness of 90 Shore A is recommended for dynamic applications and the standard of 70 Shore A is recommended for static applications.
    The 90 Shore A o-rings wasn't easy to obtain but BMG ordered from their JHB branch.
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  13. #13
    Marksman

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    On Saturday morning I drilled the breathe hole and installed everything.
    I rushed to Gotcha paintball to test the system for leaks.(I still don't have a dive cylinder).
    After firing 10 shots I was happy and packed up to head for the Inyati club shoot.
    Initially I had the screw 1.5 turns out and it read 70 bar on the gauge.
    I turned it another half out and viola +- 95 Bar of regulated pressure.( I was super chuffed that it confirmed my calculations and worked as planned)
    I shot 4 lanes and all of a sudden I could see the pellet dropping 0.5m over 30m through my scope.
    Initial thoughts where that I had a leak somewhere, but when trying to unscrew the end of the cylinder it felt tight (that was after I hand tightened it).
    I then knew there was air in the high pressure side of the regulator. I basically waited for that to leak empty before I could disassemble and inspect.
    Apon inspection I noticed the following:The nylon insert came out of the set screw, pushed the cylinder forwards and out and sealed against the face.





    I completed the shoot with my partners gun (Thanks Marnus!)
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  14. #14
    Marksman

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    It seems as if the initial problems with the soft seat has been solved, the initial material used for the soft seat was Teflon also known as PTFE. Although it really sealed well against the small edge of the piston the fundamental problem was that it has a yield strength of 13MPa and the seat came out shortly after I filled my gun to 20MPa. I suspect that when the gun was filled the heat combined with the high pressure caused it to "shrink" and move forward and seal off the reg.

    I then decided to move to Nylon for the soft seat.
    I have since shot 800+ shots with it without a problem.
    The o-rings also seems to be holding up well with no obvious signs of wear.
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  15. #15
    Marksman

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    Update on the reg:
    I’ve hit the 5000 shots mark without any issues. I am extremely happy with the regulator in the rifle. It did take some tuning to get it shooting sub 12fpe and not gulping through air reserves. The initial estimate of 3cc at 90bar seems to be sufficient for 12fpe. I went somewhere inbetween my calculated volume and Robert Lane’s 9cc at 90 bar when I drilled the hole. I should have trusted my calculation since I am now running at 2.5cc at 80bar. I grouped 2MOA yesterday at 50m from FT position with my new “tune”. I think expecting anything more than that from a R3000 gun is unrealistic. ��
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