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This is a Safety issue alert
- Thread starter steve-l
- Start date
Perhaps you suffer a reading deficit, I created a safety alert not a complaint. Yes, I had this issue for two years and I did mention the issue before here, but I dealt with it and kept shooting. I did not know what the real cause of the issue was because I shoot my gun not play with it. It was not until I had multiple reasons to disassemble the gun that I could measure dimensions to determine the cause. I also bought an extended fitting from DannFL and another vender. Both of those also interfered on my Crown.
I only milled 1.2mm all around the clearance slot in the laminated stock and solved the bind issue there. There is however another potential source of another bind. On my Crown, there is 10mm from the center of the Foster to the edge of the plenum pressure gauge. Many of my whips have a 19mm brass sliding ring on the female fitting on them that could also cause bind. Another observation is that these manometers are NOT uniform in size. (My plenum gauge is slightly larger than my bottle gauge). One touches, the other does not.
I think the extended fitting is a great idea, but the quality of the construction of these vary widely beware and I have not yet found one with a female 1/8" BSPP thread. Both of the ones I bought have a male thread.
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As a customer, how do you know that a female fitting is included in the purchase if it is not included unless the dealer tells you and he did not. I did purchase a fill whip at the time because I had nothing. Unfortunately, that did not work because all I had for the other end is scuba bottles with American scuba valves and nothing fit. The fill probe and bleed valve had a European 18mm male thread. That of course is another adventure discovering all the different HPA bottle standards, which I went through at the time. That is a story for another thread, but I ended up building my own compressor rig, compressor controls from a junkyard Bauer pump.
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I'm actually a bit disappointed in the responses in this thread from so many of the more experienced shooters here. This forum along with most other forums are designed to benefit the overall members participating in the forum. None of us know everything about everything and it is clear that not everyone reading this thread was aware of the mentioned issue. So it appears to me at least that my alert has helped some others. That's good. That is why I did it. The question must also be asked why this alert was not made before by those that knew about it? The entire subject of Foster fittings is a minefield of mistakes just waiting to happen to the uniformed.
I have mentioned in other previous posts all the variations that exist. So for those not informed, there are 3 families of threads involved, British standard, American standard and Metric. Within each family there also different diameters, different pitches and different thread forms.
British standards use a 55 degree thread form.
American and Metric standards use a 60 degree thread form.
All tapered threads like NPT and BSPT seal on their threads.
All straight threads like Gas threads, NPS and BSPP seal on either the top of the thread with a sealing washer or a Dowty seal or they can seal at the bottom of the threaded hole with a sealing washer.
My point here is that they cannot safely be interchanged. The problem here is twofold. How do you distinguish from one to another without a complete set of thread gauges? Secondly, how do you buy what you need if you don't know what you need and the advertiser does not fully identify the fitting they are selling?. It is a minefield! Because of this, FX offering a Female fitting with a male thread as a solution is grossly inadequate.
I have mentioned in other previous posts all the variations that exist. So for those not informed, there are 3 families of threads involved, British standard, American standard and Metric. Within each family there also different diameters, different pitches and different thread forms.
British standards use a 55 degree thread form.
American and Metric standards use a 60 degree thread form.
All tapered threads like NPT and BSPT seal on their threads.
All straight threads like Gas threads, NPS and BSPP seal on either the top of the thread with a sealing washer or a Dowty seal or they can seal at the bottom of the threaded hole with a sealing washer.
My point here is that they cannot safely be interchanged. The problem here is twofold. How do you distinguish from one to another without a complete set of thread gauges? Secondly, how do you buy what you need if you don't know what you need and the advertiser does not fully identify the fitting they are selling?. It is a minefield! Because of this, FX offering a Female fitting with a male thread as a solution is grossly inadequate.
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I'm just letting you know what's come with the ones I've bought.
I wonder if that's why I received the female foster fittings with my FX guns, based on the country I purchased it, so there wouldn't be a mistake.
I wonder if that's why I received the female foster fittings with my FX guns, based on the country I purchased it, so there wouldn't be a mistake.
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Good point. I don't know either. I bought my Crown in Belgium. In my experience in Europe BSPP seems to be very common in HPA plumbing, but by far, not universal. When I built my compressor output manifold I used 1/8" NPT for the male Foster, but the adjustable over pressure safety valve is Australian and it is 1/4"BSPP. All of the factory HPA threads on the Bauer pump are BSPP. Most of the American SCUBA threads appear to be Gas threads, which are adopted American standard NPS.(National Pipe Straight)
If you search Alibaba for these fittings, they can be anything NPT, BSPP or BSPT, but they rarely state if they are BSPP or BSPT. They sometimes just say BSP. Go figure.
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I really don't care whether probe or foster on an air gun as long as it hits the target but prefers foster fittings.
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Having just hit this problem with my new GRS-stocked Crown, I'm here researching it....
I've tried three female fittings so far including the one supplied with the gun and a good quality extended one but none of them will latch on. I've a strong feeling the stock is getting in the way but will have another look when there's something closer to daylight. My woodworking skills are at best modest so I'm hoping I'm wrong.
I've tried three female fittings so far including the one supplied with the gun and a good quality extended one but none of them will latch on. I've a strong feeling the stock is getting in the way but will have another look when there's something closer to daylight. My woodworking skills are at best modest so I'm hoping I'm wrong.
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As I said, I only had to remove 1.5mm all around...not so much. I only had to remove 2 screws, the safety screw and the hammer cam to remove the stock. You also have close tolerances between the forward stock mounting washer and the manometer. It is possible to gain enough clearance for a 19mm fitting.
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Ah, thanks. I thought I'd read everything but obviously missed that post. I've had the stock off already to adjust the trigger weight so I can manage that again. I won't be doing much else tomorrow so I'll probably have a go at it.
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