Destroyer Regulator Trials

Discussion in 'Weapons & Pneumatics' started by Kotori87, Apr 30, 2020.

  1. Kotori87

    Kotori87 Well-Known Member

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    Ahoy folks! In preparation for building several vac-u-destroyers, I decided to run some tests to find out which regulator is best suited for the job. After searching far and wide, and talking with as many other captains as possible, I bought three different regulators to test. They are, from top to bottom:
    1) Rock Lite regulator from Palmer Pursuit shop
    2) Battler's Connection regulator, with a disposable cartridge adapter from Palmer Pursuit
    3) an "ebay kegger" regulator, most commonly used in vac-u-gearings
    20200430_142554[1].jpg

    The test setup:
    Since my destroyer will be as stock as possible, I used one of Phil's Predator cannons with a MAV-3 poppet valve for firing. A MAT-2 air tank was included as an expansion volume, and two pressure gauges were installed, one upstream and one downstream of the firing valve. Each regulator was verified with an initial starting pressure of 150PSI. Each regulator was tested with at least two 16-gram cartridges, firing in single shots and 3- to 5-round bursts, with larger bursts when achievable. The regulators were mounted with a significant up angle, to replicate the sort of mounting I plan to use in my destroyer. I also weighed each CO2 cartridge both full and empty, and counted rounds to see if it would be possible to get two full magazines from a single cartridge. Short answer: no. But enough with that! On to the regulators!

    The first regulator I tested was the BC regulator with 16-gram adapter. This combination weighed in at 114 grams, or 4oz. Starting pressure was almost exactly 150PSI. When firing, I noticed that pressure would return to normal extremely quickly. There were minor variations in the output, with average pressure during use around 145PSI and as low as 140PSI when the cartridge got very cold. Overall performance was excellent, as expected of a high-flow regulator intended to power major capital ships. The only noteworthy drop in pressure was during rapid fire testing, when the cartridge got so cold that it couldn't boil off its liquid CO2 fast enough to keep up with demand.

    The second regulator I tested was the e-bay kegger regulator. This massive metal monstrosity weighed in at 138 grams, or 4.87 oz. It does have a small pressure guage included, but most of the mass is from an unnecessarily thick valve body. I'd heard from several sources that it struggles with rapid fire, so I was interested to test. The kegger regulator is nominally adjustable from 0-150PSI, but in practice I found that the adjustment knob was very non-linear. It took a lot of turning to go from 0 to 50PSI, but it took noticeably less to go from 50-100PSI. The last stretch, 100 to 150PSI, was crossed with just the barest of nudges, and it overshot to 170PSI. I then had to back off and try again a few times to get it steady at 155. Further reduction would be needed prior to battle, but good enough for a test. I immediately noticed a significant difference. While the BC regulator recovered almost instantly, the kegger regulator was much slower to recover after each shot. Pressure would quickly climb up to around 130PSI, but it would take a good 15 seconds or so to return the rest of the way. Firing in spurts would cause pressure to drop much lower, presumably as I used up more gas from the accumulator. Of greater concern was the pressure drift. Over time, the pressure setpoint went up. Highest observed pressure was in the upper 160's. It may have gone even higher but I didn't have the patience to find out. Overall, this regulator proved overweight and underwhelming, but that's about what I'd expect from a cheap ebay regulator.

    My final test was the Rock Lite regulator. It weighed in at 70 grams, or 2.47oz. It is also by far the smallest regulator, which is an important consideration for a tiny destroyer. It was also designed for paintball use, which provides a good high flow rate. The Rock Lite is adjustable from 0-250PSI. Unlike the kegger regulator, it has a very smooth, linear adjustment of pressure, so it was easy to dial in the desired pressure of 150PSI. Then I started the firing testing, and that's when things went bad. The good news is that the Rock Lite provides plenty of flow, just like the BC regulator. Unlike the BC regulator, though, the Rock Lite had a terrible time maintaining its set pressure. Pressure varied wildly from as low as 130 to as high as 170. After a while, I think it stopped regulating at all, because pressure went up to 180 and slowly rising. When I touched the frost-covered CO2 cartridge, pressure spiked up to above 200. I tried dialing down the set pressure with no result. Several further extremely cautious shots showed that the pressure output only rose with heat input to the cartridge, so I suspect the regulator froze and stopped regulating, while the cartridge was so cold that it couldn't keep up with demand. This is not an issue I've seen before from Palmer regulators, but this particular one does it a lot. I'm curious if anyone else has similar issues, or if I just got a lemon.

    Other lessons learned:
    The 16-gram cartridges I was using are not actually 16-gram cartridges. After weighing each cartridge before and after, I found that 2/3 or them contained only 14 grams of CO2. Only one contained 16 grams, and the last contained 17 grams. On average, with a good tweak on the cannon, I was getting between 60 and 70 shots. Good enough for one sortie plus a bit of tweaking, but that's about it. Other captains have reported similar performance from their 12-gram cartridges. If that is the case, I wonder how much CO2 those 12-gram cartridges actually contain, and whether it's worth it to use larger, more expensive cartridges that can actually supply two sorties worth of gas.

    Speaking of gas, one of the noteworthy limiting factors in even the BC regulator's performance was the ability of the small cartridge to keep up with demand. It takes a certain amount of thermal energy to boil liquid CO2 into usable gas, and that energy has to come from somewhere. There's a certain amount of heat stored in the metal of the cartridge, but once that gets used up, it's all down to heat transfer from the air to replenish. This effect was quite noticeable with the BC regulator. After a particularly aggressive burst, the cartridge may be so cold that it takes a minute or more to recover back to normal performance. During rapid-fire testing with the BC regulator, pressure output dropped to about 100PSI, and did not recover until I warmed the cartridge with my hands. BC's regulator may be good enough to supply dual high-flow sidemounts at 10+ rounds per second, but these small destroyer CO2 cartridges certainly cannot.
     
    Last edited: Apr 30, 2020
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  2. Kevin P.

    Kevin P. Well-Known Member

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    Great post.

    My direct experience and the experience I've observed with Palmer's is that they are notorious for pressure spikes. Last time I had one in a boat was 2007ish, I think I still have a couple. I've heard oiling them can help, but not worth it with the BC regulator now a days.
     
  3. BigGunJeff

    BigGunJeff Well-Known Member

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    Awesome testing and writeup. I'm happy to hear the BC regulator worked well because I'm using one in my Nassau.

    On the cartridge discussion, I solved the freezing issue in my Roma by cutting out part of the hull and putting in an Aluminum plate. That and an aluminum cradle allows the tank to suck heat out of the pond to maintain a reasonable temperature.

    Obviously a weight issue in a destroyer, but maybe it could be made very minimal weigh wise
     
  4. rcaircraftnut

    rcaircraftnut Well-Known Member

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    Reverse water cooling. Use a coil and a micro pump. Simple solutions for simple problems. Lol. Could even just put the pickup in the propwash and no need of a pump.
     
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  5. Z Boat

    Z Boat Well-Known Member

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    I have had the same spikes with a Palmers.
     
  6. Kotori87

    Kotori87 Well-Known Member

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    I did some disassembly this morning and took some more photos. I was already familiar with the BC regulator, but it makes for an interesting comparison to the other two regulators.
    20200501_065643[1].jpg 20200501_065655[1].jpg
    Here is the BC regulator, with cartridge adapter. Parts are arranged right-to-left, bottom-to-top. First you have the cartridge adapter, then the regulator base. In the middle column, you have a small shim washer to ensure proper 150PSI output (thanks BC, that rocks!), then the spring and piston. Finally to the left is the regulator body with output ports. Very cool arrangement of the regulating hardware here, with the actual sealing surface at the bottom, the spring in the middle, and the low-pressure region at the top. The sealing surface is a small white plastic ball on the tip of the piston. This does slowly wear out over time, requiring replacement.Unfortunately I do not know what type of plastic it is, so at this point the only option to get replacements is to order a rebuild kit. Also worthy of note is the enormous flow this regulator is capable of. Just look at that second picture, and see the diameter of the orifice. The only downside this regulator has is that it can only be adjusted using shim washers, so it cannot be used in Big Gun or other formats that limit penetration or muzzle velocity.

    Also worth pointing out, the cartridge adapter I used is basically a solid block of aluminum with regular paintball threads on one end, and 1/8NPT threads on the other end, with a brass fitting that actually fits the cartridge. It can very easily be cut down to save weight and length.

    20200501_065602[1].jpg 20200501_065551[1].jpg
    Here is the Ebay Kegger regulator. The first thing that stands out to me is how much of this thing is solid metal. There is a tremendous amount of wasted weight here. No wonder it's the heaviest regulator. Lets start with the base. That's the part with the pressure gauge and cartridge threads. In the top view, you can see the actual valve portion of the regulator screwed into the base. Notice how there's a pin that goes from the high-pressure side to the low-pressure side. That pin gets pushed down by the piston and spring, allowing CO2 into the low-pressure side. However, the pin fills up most of the orifice, so there is very little room for gas to flow. No wonder this thing has such a poor reputation! It can barely pass any gas. You'd need an enormous accumulator to get more than one good shot every 30 seconds with this thing. On the bright side, with such a low flow rate, it's highly unlikely to frost up the valve seat and fail. Next up is the piston and spring. The piston sits inside the base, and gets pushed up by the gas in the low-pressure side. This in turn is opposed by the spring, which opens the valve when the pressure exerted by the low-pressure gas is less than spring force. The spring is strong enough to reach 150PSI, but its short length means it is difficult to set the pressure. Last is the regulator top, with adjustment screw. Like the base, this thing is seriously over-built. Another thing that stands out to me is the lack of drainage. This portion isn't sealed, so it can be flooded during a sink. There is no way to drain it short of disassembling the regulator, which is inconvenient pond-side. If not drained, however, it could rust the spring and/or gum up the works.

    20200501_070440[1].jpg
    Unfortunately I couldn't get any good pictures of the Palmer regulator. I was able to partially disassemble it, but not much stood out. It uses the same basic hardware arrangement as the ebay regulator, but with a larger orifice to support higher flow, a longer spring for more precise pressure adjustment, and no unnecessary mass. I could not disassemble it any further than this, though, so I could not check the sealing surface. I have no idea why this regulator is so susceptible to freezing, but certainly it has failed open multiple times. Like the ebay regulator, this one has no good way to drain water from the non-pressurized area. Out of curiosity, I disassembled a different fifteen-year-old old Palmer regulator, and was greeted by a crumbled pile of rust in place of the spring. Now I need to check my other Palmer regulators for rust. It's easy to prevent, too - just gotta drill a couple drainage holes in the non-pressurized portion of the regulator.
     
    Last edited: May 1, 2020
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  7. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    Not to shit on all the good info you're putting out here, but modifying components on the high pressure side is not permitted in the ircwcc.
     
  8. rcaircraftnut

    rcaircraftnut Well-Known Member

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    Nothing the manufacturer couldn't cure. I took it as he was saying the manufacturer could and should make it lighter. In other words saying it is a poor choice for our uses. However. Not everyone knows these things so I can see where it bears saying. Safety first rite?
     
  9. Kotori87

    Kotori87 Well-Known Member

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    Indeed, it is a very simple modification for a manufacturer to make. I understand the basis behind the design, it is very easy to assemble and disassemble by hand. But in our application, size and weight is a more important concern. I also wonder what it would take for whatever company builds BC's regulators to make a base that accepts cartridges, so an adapter wouldn't be required at all. That would be the ideal solution.
     
    Last edited: May 1, 2020
  10. BigGunJeff

    BigGunJeff Well-Known Member

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    Again, I'm liking the Battlers Connection Regulator. It's built really well and very easy to service. To that point, the rebuild kit is $1.50, so pick up a few and you'll be fine.
     
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  11. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    Right. I know it was common practice back in the day to cut/chop/lathe extra material off to save weight which led to some sketchy high pressure setups. Didn't know if Carl was referring to that kind of modifications or not but figured it didn't hurt to mention.

    Actually, @Charley had been talking about something just like that a while back. Don't know if anything ever came into fruition though.
     
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  12. Charley

    Charley Vendor

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    Hey Guys,

    Yes this was an item that was brought up some time back I designed a unit that would allow an 1/8"npt thread to apply your adapter to. It never grew to fruition as the demand is very low and I have to have so many pieces made.
    here is the design render next to ASA design.
    upload_2020-5-1_20-56-11.png
     

    Attached Files:

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  13. Nate G

    Nate G Well-Known Member

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    Nicely done and some excellent info.
    I used the Vac-U-Gearing as my primary ship at Nats last year. I have used the Keg reg and BC Reg with adapter.

    In practice:
    1. the kegReg is an OK starter reg as intended by PhilP at VUBoat. It suffers from low flow and icing hurts it even more.

    2. The BC worked great. I worked with the other 2 destroyer captains testing setups and found that with a proper tank and BC Reg. The cannon system was ready for prime time and I would use it in a larger ship with no regrets. The limiter is the cartridge and its freeze up. This is just a limitation of the physics and geometry. As noted by others, there are several ways to help this and they all take space and weight. Now, since these ships need 8 ounces of ballast anyway, this could be tried - the plate in hull and cooling ring would work.
    That said, in practice, I was very happy with Charley's reg with Palmer adapter for the week of Nats and at several regionals. Once I realized that I needed to not shoot more than 20 shots at a time - which you don't do much with this type of ship - I was fine. This is my std setup now for class 1's.

    3. The palmers have always had an allure because they look well made and are the lightest . They just don't hold calibration unless you are lucky enough to get a good one. I have one full sized one that I used for over 10 years with absolutely no issue. others, not so much. I have not used on in battle since purchasing and using the BC Regulators of the current generation.

    4. Charley - I would love to see that product in your lineup. It would answer most of the issues and your quality with these Regs has been superb! I think interest in these small ships will increase with the new technology making these easier to build and battle. Great for a secondary ship.

    5. A thought: instead of a nice taper to the cartridge adapter, make a straight cylindrical profile and machine in fins to act as a heat sink. I think this will help or eliminate the freeze-up issue.

    Nate G
     
  14. Kotori87

    Kotori87 Well-Known Member

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    Wow, that adapter would be amazing. What sort of minimum order would be needed to make this? I could easily use four, and I've seen a lot of other vac-u-destroyers with the kegger regulator that could use an upgrade.
     
  15. Nate G

    Nate G Well-Known Member

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    Agree with Kotori87.
    Charley, the interest in these is increasing.
    I would want 3 for me and my high school group would want a few.