Royale 500 Regulated Pressure Gauge Project

I took on a little project and thought I'd share if with you folks. The more I get into PCPs the more I want to know. Knowing your regulated pressure is a key to performance and accuracy. Finding out what that pressure is can be a pain if you don't own a gun with this secondary gauge. With the Royale's finding this pressure (my way) involved removing the gun from the stock, bleeding off the receiver, removing the stock bolt stud, screwing in a special adapter, hooking up a gauge, pressurizing the receiver again and reading that pressure...finally.
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Well I got tired of this method and decided to add and on board regulated gauge.
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How I did it....
First I made sure that where I wanted to add the gauge would get me in behind the regulator without screwing something up in the process.

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Next I CAREFULLY and as precisely as possible measured and marked the location with a pointed awl, carefully mounted the receiver with the action in it in a vise, got everything leveled up and centered, said a good long prayer and drilled a small hole through the stock and just touching the receiver.
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Next, I pulled the stock off the receiver and was pleasantly surprised to find that my drill bit hit the very center of the receiver.
Almost forgot to explain how I bored the hole through the stock. I used a 1" Forsterner wood bit and followed up with sandpaper wrapped around a 3/8" slotted to enlarge the hole large enough to accommodate the gauge.
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Next I re-positioned the receiver with all the internal components removed back into the cushioned vise and drilled a 1/8" pilot hole through the receiver into the plenum space. After drilling the pilot hole I drill that hole out to 11/32". That's the recommended bit size the 1/8X28 BSPP tap. I then chucked up a BSPT (tapered) tap into the drill press and started a few threads by rotating the chuck by hand. Keeping the tap in the drill press ensured that the hole would be straight. I then switched over to the BSPP tap and finished tapping the hole by hand to the depth I thought appropriate.
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It actually tapped pretty easy with a new tap in use. At this point I machined a small delrin spacer/washer to set down in the bottom of the hole for my gauge to seal against. I ended adding a O-ring in between the gauge and the delrin spacer.
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The gauge I added wasn't the easiest to read for an accurate pressure reading so I'm in the process of ordering another FX gauge that is incremented in 10bar divisions. Once I get it in I'll try to get the gauges facing the same direction for a cleaner appearance.
Hope ya'll enjoy.
Jimmy





 
Thanks guys,
Dennis, I don't think I qualify as a craftsman but thanks for the compliment, I look at the work of 220Swift, Weatherby and I believe he goes by Kingman on GTA. They are the true masters. I always envy those guys with the skills and the creations they come up with.

10X, I didn't really know that I had issue with creep until the last pressure check I did on the regulator. I thought that I had left it at 155 and it had settled way down to 143. I reset it a few days ago to 161bar thinking that it would settle to a lower setting after a couple of hundred cycles but it seems to be staying put. What I have noticed since I installed the gauge is that it's creeping up some until I fire a shot and then it looks like it's settles back to 160 on the gauge. It'll definitely be a benefit having an on board gauge now. If it continuous to act up I may pull in and adjust it down to 155 and see how it acts there. 10X, what gun are you putting the regulator in?
jk

 
Jim,
I'm putting the reg in (a Gen1?without the power wheel adjustment) Royale 400 or the regulator breather hole....the hole is 3/4th drilled and a 2mm drill is guided perfectly by the factory pilot hole....but still...makes a guy nervous drilling into higher price tagged toys....
You sir, bravely go for it...so I voted you a +....cuz your thread puts me at ease with my project....I'm more concerned with aluminum chips getting where I don't want them...so that's where I'm taking great care to block/mask/isolate the mess.
 
Wow! Nice write -up! Wish I had more time and Know-how to do things like this. I have really enjoyed the few thing I have done. The more you know about the rifle the better you will be able to use it and to optimize performance!
Great job and thanks for sharing the steps!

Doc
PS- I can't give you any more +'s. This projects deserves a few more +s
 
Thanks Doc, you and your stock work is amazing. Always enjoy everyone's projects btw.
Mubhaur, that sounds kind of like Ernest's little bottle he added to one of his Impacts. I don't remember if it was to increase the plenum or just to increase his high pressure capacity.

I have learned that my regulated gauge is almost 10bar too high compared to my Crystal test gauge. Hopefully the one I get from FXUSA will be closer and easier to determine the correct reading. The one in place now is in 20bar increments which leaves room for lots of guessing.
Jimmy