My first regulator.... that really works

[lloyd-ss]

I've attempted making a few regulators in the past, applying less than 100% effort and achieving results that reflected such.
This time I had a goal in mind and did the requisite design work, and the results are pretty fair.   Input is variable up to 4,000psi. Output is field adjustable with An allen wrench from zero to 3,500.  I am testing it in the pic with 3,750 input from the CF tank, regulated down to 2,950psi.  I am using the gauge and bleed from the second tank, but the valve is closed to isolate the regulator.  So far, I have seen no creep. There are about 3 turns per 1,000psi, so the adjustability is fairly accurate. That is why it is so long.
I could be wrong, but I don't think you can buy a reg with this adjustability for less than an arm and a leg.
I'll get some pics of the internals. They are nothing special, just accurate.
If you can buy something like this, let me know.  It was a lot of work, LOL.
Lloyd-ss

[rsterne]

Now THAT is a project I could use.... photos of the guts will be great!.... 

Bob

[Pellethuntr]

Now THAT is a project I could use.... photos of the guts will be great!.... 

Bob

+1 on the pics, that is a cool project 

[aack73]

looks like a great idea lloyd-ss. regulators that accept 4k to 6k input with that much adjustability run $300 +

[airpuffhunter]

great project hope it work well

[ezman604]

Congrats!!!!
Totally awsome project Lloyd. Would love to have a fraction of your skills and knowledge. I can certainly send you a few airguns to test this with.

As long as I get a regulator for each.
Keep up the most excellent work sir!!!!
SAFE & Happy Shooting!!!!
Dave
 

[amb5500c]

Is it painful being so smart? Way too much information to fit in my head.
Richard

[OldmanJunky]

Yeah for a barebones new regulator, you are normally looking at around $300 + gauges and such.

That's awesome lloyd.  Let me know when you start shipping them

[lloyd-ss]

You guys are funny.  No plans on selling anything like this.  It's going into a one-off project I've got going.

Actually, it isn't my idea, I got the basic ideas from this page
http://www.zdspb.com/tech/misc/maxflo.html

The one I built is a combination of the AKA Sidewinder with the pressure adjusting screw in the end, and the Ion Vertical reg, but with Belville washers instead of a coil spring.  The Belville washers are needed to handle the spring loading that high output pressures produce in a reg.
Pictures are in the works.
Lloyd-ss

[rsterne]

If I understand those two diagrams correctly.... It looks like you move the high pressure seat up and down to change the regulation point?.... What are you using for a Belleville stack to achieve the wide adjustment range?.... What size washers, and what piston diameters?.... I'm wondering if I can start with a piston from a Ninja and make a housing to make it adjustable.... I've already made one regulator using that piston, and they are easy to obtain....

Bob

[lloyd-ss]

Here are the pics.


7/8 OD x .065 wall tube 4.72 long.
side input. output on the right. set point adjustment screw is in the left end.


Partially disassembled. Initial assy just barely compresses the Belville stack.
With springs barely compressed (just enought to keep them from rattling, that is minimum pressure.


All apart now.  The air enters thru the fitting into the side of the body, captured between the 2 orings on the adjustment screw.
Into the small hole into the adjustment screw, then thru an axial hole out the right hand  end of the adjustment screw.
The spring stack is 11 pairs of a .730 OD x .390 ID. one is .028 thk(171 lbs when flat) & one is .034 (326 lbs when flat).
So a load of approx 500 lbs will flatten the stack. Doesn't matter if it has one pair of springs or 11 sets of springs.
The eleven sets give a total travel .231" which is how you get a 3500 psi adjustment range.
Piston bore diameter is .430 (.145 sq in) so the springs will go flat at about 3500psi.


Screwing the adjustment screw OUT raises the pressure.  air travels out the tip of the adjustment screw, up a short distance
along the side of the small end of the piston, then in thru the side hole in the piston, and then up thru the center of the piston. 
In the piston chamber, it presses down on the piston, flattening the springs until the small delrin tip on the end of the piston seals up the air input hole.


Here you can see the plastic seal plug that stops the input of HP air. But in this pic you can't see how the sir travels up thru the piston.
 You can see the side hole in the 2nd and 3rd picture above. An important thing to note about this type of reg is that
it is not self venting. Therefore, you can start with the air pressure set low, and screw the adjuster OUT to increase
the pressure. But to LOWER the pressure after the tank is filled, you can't just screw the adjuster in because the HPA can't vent.
You have to bleed the air from the tank, and then screw the adjuster in. 
In the part on the right you can see the .430 dia piston chamber.


That's the basics

Edit- 10-30-12- by Lloyd-ss- Studying this some more, I think it can be simplified by swapping the plastic sealing element and the tiny axial hole between the adjuster and the piston, lengthening the nose on the piston, and shifting the input hole toward the right.  That way, no air would actually have to flow through the adjuster.  It would eliminate one potential leakage point.  The functionality would be identical.

[rsterne]

Excellent writeup, all the details are there, for sure.... I never really gave much thought to the total travel required for that adjustment range, and hence the need for a long Belleville stack.... It would mean the Ninja piston would likely be too short....

RE your EDIT.... It took me a while but I think I understand now.... You would eliminate the upper O-ring in the photo from the adjuster, right?.... The air would come up along the side of the adjuster, across the Delrin seat, and then into the axial hole in the end of the piston.... Why would that hole have to be off center?.... You would no longer need a side hole in the piston, the air would pass straight through the middle, through the hole in the seat.... Or am I missing something?....

Is there an easy way to balance the pressure on the adjuster so that it can be adjusted under pressure?....

Bob

[lloyd-ss]

Is there an easy way to balance the pressure on the adjuster so that it can be adjusted under pressure?....

Bob

Bob,
This part first. 
Turning the pressure up is easy, just back the adjuster out.
Reducing the pressure is not as easy.  If the application of this reg is in a typical situation, then there will be a tank on the output side of the reg.  If for example, it is already at 2500psi and you want to set it to 2000, then you will somehow have to reduce the pressure in the tank for that to happen. Because the piston is in a state of equilibrium between the spring stack and the output air pressure on the piston, the adjuster, if you are trying to reduce the pressure, will in the example above, be trying to move the piston to compensate for 500 psi, or 72 pounds (.145 sqin on the piston). My guess is that the adjuster would badly gouge the plastic seat if it were trying to apply 72 pounds of force to the plastic end on the piston. Adjusting it a few psi would work ok, but not 500 psi.
There are industrial regulators with built in unloaders, but you would essentially be trying to drain the gun's reservoir.  My plan for that situation was to have an inline valve on the input to the reg that would be turned off, then either bleed or shoot the gun down to the desired pressure, and then turn the adjuster in and open the air up again.  As I said though, you could probably adjust the pressure 50 pounds or so without bleeding. If you have a big tank with a high shot count, shooting the gun down could be slow. A bleeder would be necessary.
Lloyd-ss

[QVTom]

Beautifully done!

Tom

[lloyd-ss]

Excellent writeup, all the details are there, for sure.... I never really gave much thought to the total travel required for that adjustment range, and hence the need for a long Belleville stack.... It would mean the Ninja piston would likely be too short....

RE your EDIT.... It took me a while but I think I understand now.... You would eliminate the upper O-ring in the photo from the adjuster, right?.... The air would come up along the side of the adjuster, across the Delrin seat, and then into the axial hole in the end of the piston.... Why would that hole have to be off center?.... You would no longer need a side hole in the piston, the air would pass straight through the middle, through the hole in the seat.... Or am I missing something?....
....

Thanks Bob,
Look at this one, it is what I think will be the easiest to make, and I like that.

http://www.zdspb.com/media/tech/regs_akalmplpr.JPG

All these PB regs are made to work with 800psi input ( The usual paint ball tank already has an 800 psi reg mounted, so most of these regs are designed to take 800psi down to half that or less.  And the output is always set to achieve 299 fps with a 66 gn (?) paintball, so they need very little adjustability. We need a lot more, plus a very high operating pressure. You could possibly preload the spring by screwing the two main endplugs in so that the miinimum pressure was always 1000 or so psi.  I don't see why that wouldn't work.

This reg is more ascience project than anything else, LOL
Lloyd

[rsterne]

That diagram is functionally exactly what I was describing.... There are no holes in the adjuster, only a seat.... The HP air enters beside it (with yours I just envisaged removing the upper O-ring).... The hole in the piston is straight through, no hole in the side.... Easy to make.... I like it....

I understand the problem about screwing in the adjuster to reduce the pressure when the piston is loaded.... It would likely destroy the Delrin seat.... Never thought of that.... A bleed fitting in the hose to the gun (or built into the LP side of the regulator) would seem to be the way to lose the least air.... You need to be able to bleed it to remove the hose anyway, and the Foster QD on the gun has a check valve in it to prevent backfilling the hose....

Bob

[Rescue35]

Lloyd,

You do some great work sir! Truly inspirational.

BTW, That is a very LARGE coffee cup you have that carbon fiber tank sitting in! I thought I went through coffee quick.

[lloyd-ss]

Rescue, ha, ha, you a funny guy, too!  It is a good thing i have small deck facing the woods right out the back door of my shop. Saves a lot of trips to the house. LOL
lloyd-ss

[rsterne]

Lloyd.... I'm missing something on how this regulator design works in terms of the maximum pressure required to flatten the stack.... You say that the piston bore is 0.43" (0.145 sq.in.) so that takes 3500 psi to flatten the stack (508 lbs).... Don't you have to subtract the area of the lower end of the piston?.... The lower chamber is at the same pressure as the upper (once the regulator closes).... Let's say it is 1/2 the diameter of the large end.... It's area would be 1/4 (of 0.145 sq.in.) = 0.036 sq.in. so the total effective area would be 0.109 sq.in.... That would require 4600 psi to flatten the stack....

Expanding on that thought.... If you move the HPA inlet to the smaller chamber, it will now be running at, say, 5000 psi.... The chambers are no longer at the same pressure (once the regulator closes) because the valve is on the end of the piston.... The force OPENING the regulator would now be increased by 4500 x 0.036 = 180 lbs.... making the force to flatten the stack (and overcome the HPA) 680 lbs.... With the 0.145 sq.in. larger piston opposing that, it would take 4700 psi to flatten the stack....

Please review the above and let me know if I'm losing my mind....

Bob

[lloyd-ss]

Bob,
I think you have it partially right.  First, with the design I have, it will indeed take about 4600 psi to flatten the stack.  Good catch.  The consequences of that are that some of the axial travel is lost... approx 1/4 of it. Because the adjustment can be screwed in and out quite a bit, that is not a problem, but a diameter for the upper part of about .48 would have been better.

For the other style of regulator that you are talking about, the scheme you are mentioning will not work, for exactly the reason you are citing. The moving part of the reg that makes the seal has to be a straight tube, thin walled and small dia, with no steps on the high pressure side.   Steps will cause the regulation to vary significantly with changes in the tank pressure. 
The style that I made, although not fully balanced, is only susceptible to imbalances in relation to the area of the tiny inlet hole that supplies the HPA.  For the other style, that imbalance is in relation to the frontal area of the moving seal tube.
I hope that makes a little sense.
Lloyd

edit: I checked my left over springs  and it looks like I can replace all the .034 thick ones with .028 ones, which will will pretty much restore the full travel to the regulator.  Thanks for that catch, Bob. I haven't done all the calcs yet, but I will when I take it apart.
Lloyd