Flyng Dragon PCP Air Tube Failure

[Tater]

That was one of the very first suggestions given directly to the participants.

Did they get people out there with metal detectors? If they did I apologize, I must have missed it.

[Fudgey Sycles]

Id still buy one.

Matter of fact if someone doesnt want theres anymore?

[tracker1955]

I would still buy one too. I just recommended one to my brother. I believe that Mike will be checking them to make sure he isn't sending out an unsafe product, now that he is aware of it.

[vigilandy]

AFAIK the "explosion" tube has not been located...or at least reported. This one was purchased in February.
I offer it as backup for the warnings I have given. I do not need to add more details...or shouldn't need to.
Those that have been around here very long or know me personally can attest I have no agenda besides the safety of our family!!!

Thanks for the info Dave!  I think you've done a great job in monitoring the situation for us.  As much as I hated to do it,  my three FDPCP are currently mothballed. 

[sixshootertexan]

As a machinist with 35+ years in the business I can tell by those pictures what happen in the process. The die head had at least one broken die most likely all 3 or 4 (depends on the die head style). To make the threads to be able to thread into the mating part the die was adjusted to cut smaller.

[nervoustrigger]

Well, the first FD PCP I took apart (newer glossy-tubed version) had its threads well formed and within specified dimensions.  And when the parts were mated but not tightened against the seal, there was just the slightest hint of perceptible play, certainly what I would characterize as a secure fit. 

Last night I took apart a second one, an older matte-tubed version, and both the tube thread major diameter and receiver thread minor diameter measured within 0.001" of the first one.  Visually the threads are sharp and distinct.  And again, the parts mate securely.  Andy, this rifle is the one you sent me.  No mothballs here

[nervoustrigger]

As a machinist with 35+ years in the business I can tell by those pictures what happen in the process. The die head had at least one broken die most likely all 3 or 4 (depends on the die head style). To make the threads to be able to thread into the mating part the die was adjusted to cut smaller.

Dez, do you have a measurement of the major diameter on that tube to confirm Ricky's suspicion?

[Fudgey Sycles]

Thenks Jason. or which ever one you are lol =) Ill learn your name..


thats my point.. I wonder who ever took apart that barrel Dez posted.. whats the backstory to it. You know rifles. youve been around them. You posted details.. no assumptions to be made.


Pics by any chance?

[Wood Boats]

They say a picture is worth a 1000 words. In this case, these speak volumes. I hope you choose to listen.
Please remove your FD-PCP airguns from service until they can be properly inspected.

Could we please have descriptions to go with these photos?  I am not trying to be a smart @@@ here but having done failure analyses these images raise more questions than they answer.

We seem to be seeing two different tubes.

[Motorhead]

They say a picture is worth a 1000 words.

We seem to be seeing two different tubes.

Daves top 2 pictures are the same end, but tube being rotated for 2nd ... 3rd picture is the other end of tube that contains a shorter threaded portion.

[rsterne]

To add some clarity, the parts in the photos did NOT fail in use, the gun was inspected and removed from service as a result of the incident in question.... This gun was disassembled and reassembled several times (they are, after all, sold as a "tinkerer's gun").... However, anyone can understand that the damage to those steel tube threads could not possibly have occurred from screwing them into (not crossthreading) the much softer aluminum receiver.... although the damage to the receiver threads could most certainly have occurred by installing and removing the tube, with those horrible threads on it.... If the tube was crossthreaded into the receiver, there would be evidence of that, and even that would not have damaged the tube threads closest to the shoulder on the tube, because you couldn't have screwed it in that far (if crossthreaded)....

To further clarify, this is NOT a tube from an XS-60c, made in China, but one from an FD-PCP, made in the USA.... They are longer, and a different ID and OD than the original tubes, but are supposed to be threaded 22mm x 1mm to match the original receiver.... In my personal opinion, I see no possibility other than the tube threads were manufactured like that, passed quality control during installation, and were supplied to the customer in that state.... If someone else has any other reasonable explanation, I am prepared to listen....

While I would hope that this is an extreme case, other FD-PCP tubes that have been checked since the event that started this thread have been found to be undersize.... by that I mean smaller than the tolerances listed on "Engineer's Edge" as I posted at the top of Page 10 of this thread.... It is because of the condition of the tube in these photos, and subsequent reports of undersized tubes, that the GTA Administration felt they had to act by recommending that all FD-PCPs be degassed, disassembled and inspected to insure safety before further use.... I wholeheartedly support that decision....

Bob

[SpiralGroove]

Thanks Bob and Dez,
Take the air cylinder in question off your XS60c and inspect before continuing to use
Pretty simple vs. the alternative ............. Kirk

[WHITEFANG]

I have steered clear of this thread. But I have to admit I have kept up with each post and picture.

I have to come forth as the (FANG / WHITEFANG/LOBOWHITEFANG / Owner of JUNKYARD AIRGUN'S ) Say that I back EZMan  on his stand on the parking of the said gun.

Much reported data has come forth and is recorded here on the GTA. BUT, as always some unknown to all lingers outside the box. Just the way this business works. But SAFETY for the community is of the MOST importance.

Not taking a side to anyone but EZman for his making a bold statement that is justified on the gun. Or any issue of such reguardless the brand after all the findings by members of any forum. Some may be questionable but for the most the GTA has many qualified engineers and craftsmen that know there occupation.

I have to admit in my work of QC the last pictures were not in anyway or form exceptible as a true craftsmanship. But
Thanks Ezman!! You have controlled the issue sir!!👍

FANG💀👻
JUNKYARD AIRGUN'S 

[MicErs]

From what I have seen in these pictures, the problem appears to be poor manufacture of an aftermarket tube?  Is there any evidence of receiver issues?  I have not seen any pictures which would lead me to believe the receivers are faulty?  Have people measured the receivers and are they consistently within tolerance?

Please keep cool heads lads.  Nobody is pointing any fingers at anyone. Please don't make more work for the moderators, I cause them enough grief for all of us.

Has the group consensus distilled to poor QC on the part of the aftermarket tube?  Is there more than one manufacturer of the aftermarket tube?  Actually the thread has interested me in possibly getting one of these after the forum's engineers bless the fix.

[ezman604]

There are too many unknowns in this whole deal to narrow it down for certain. As you state, we are not here to point fingers or assign blame to anyone. THAT is not the point and will not be on this forum. The point is there is a possibility of an unsafe setup and we are STRONGLY advising folks to empty their FD-PCP and wait for the safety checklist to be posted.
These can and will be good airguns. And to back that up, I'll step out and say this. I have one that was donated by a member to use as a monthly GTA raffle item. We put that on hold after this thread began. After this airgun is checked and retrofit (if needed) it WILL go back up for raffle. That would not happen if we didn't feel sure of the product safety and the forthcoming inspection checklist.

[rsterne]

A few receivers may be marginal as to thread tolerance, but if the tube was on the large size of the tolerance range it would not be a problem.... I think the big problem is that some FD-PCP tubes are at, or below, the minimum tolerance diameter.... Mating that with a large ID receiver is even more of a recipe for disaster.... I suggested way back on Page 10 that people disassemble and measure their tubes and compare them to the tolerances given, but VERY FEW have either done that or reported their findings.... If you measured your tube and receiver, and you didn't publish your results, you aren't helping get to the bottom of the problem.... be your results good or bad.... JMO.... Hopefully, now that the GTA has issued a warning to do this, more will heed the request and share their results.... There will, as DEz mentioned, be a safety checklist coming to assist you....

Bob

[spike]

gen 2 gloss black tube , major diameter .8595 , receiver minor diameter .830

[Sprungout]

Gen 1.5 glossy tube. Tube threads= .859 and receiver threads= .823. Threads are in pretty decent shape, nothing like the picture above. I've also noticed the fill end of the tube on mine is spaced further from the barrel than most other guns? The tube has quite a bit of wiggle until tightened, and I'm seeing the receiver is on the low side of spec measurement.

[rsterne]

I can only comment on whether the measurements of your tubes are within or outside the tolerances published on "Engineer's Edge", not on the safety of the combination.... Obviously a small receiver ID and a large tube OD will have less "wiggle" and greater strength.... If the receiver ID is on the large side and the tube OD on the small side, there is less overlap of the threads, so less strength, and the parts will "wiggle" more....

spike - tube and receiver within tolerance....

Sprungout - tube within tolerance, receiver 0.0005 undersize.... However if you state that the tube wiggles quite a bit that doesn't make a lot of sense.... I would double-check the receiver ID just to make sure....

Realistically, the only time an undersize receiver would be a problem (smaller ID than spec.) would be if the tube OD was on the large side and the tube was difficult to thread into the receiver.... The same would apply to an oversize tube (larger OD than spec.).... not an problem unless the receiver ID was on the small side.... Basically, the threads can't be too tight if they thread together by hand, IMO.... in fact that is what I would prefer....

Bob

[Sprungout]

Well, I checked it again and got the receiver to read .8235. I spent many years working on Japanese motorbikes, so maybe my idea of a lot of wiggle could be skewed by the precision of those machines. At any rate, I think it's good to go and I'll see if Mike has a reseal kit while I'm already dug in. Should I wait until an official checklist/decision comes out before reassembly? This thing is just too accurate for $80, I don't want to trash it.