Flyng Dragon PCP Air Tube Failure

[Ribbonstone]

Are lots of ways for any PCP system to fail....I'd rather not have a mal-treated, unmaintained tank up to my face as a stock either.

[avator]

I have a question... can the ID of the tubes safely be expanded to create a better/safer fit? I mean, we really aren't talking about a whole lot here are we? Would the threads be further compromised if stretched just enough?

DO NOT stretch the tube to increase the diameter.... Doing that means you have exceeded the yield strength of the steel, which could either lead to it cracking where it is thin (ie at the bottom of the threads), or breaking where a crack had already started.... REALLY BAD IDEA....

Thank you.

[spike]

 fill cap end of tube major diameter .059 , receiver end of tube major diameter .0595 ,just checked the fitment of the fill cap to the receiver end of the tube , as one would expect from the higher reading of the receiver end , the cap screwed on more snugly and with tighter fit than on the fill cap end

[rsterne]

I assume you mean 0.859", not 0.059".... I'm a bit surprised you can feel the 0.0005" difference (on tubes near the minimum size) by using the fill cap.... it must be a fairly snug cap....

Bob

[Rescue35]

I'll offer to measure and inspect these parts for anyone that would like. Just need to get them to me. I travel North Alabama and Mississippi ad well as West Tennessee and Kentucky regularly.

Thanks to Rstern and DEzman for heading this effort for the community sake. Thanks to PakProtector for bring up this subject. As for those questioning Dave's integrity, Iv'e had the pleasure of meeting him and exchanging ideas on a couple of occasions. He is a stand up guy and if I had one of these rifles I would take him at his word for what needs to be done.

[spike]

I assume you mean 0.859", not 0.059".... I'm a bit surprised you can feel the 0.0005" difference (on tubes near the minimum size) by using the fill cap.... it must be a fairly snug cap....

Bob

yes , I meant .859 , yes the cap fits snug on the cap end and a bit more so on the receiver end , cant get the fill nipple out with out marring the brass valve to measure the minor diameter of the cap

[bubba zanetti]

An update on this matter:

As previously stated the GTA Staff has been working on solution to the possible FDPCP problem that was brought to all our attention. I am 'bumping' this thread as the GTA Staff waits for some answers to so we can provide some sound solutions to the owners of these air guns.

At this time, we have a sticky in the GTA's Announcement Gate listing out fellow member rsterne's (Bob's) tolerance recommendations regarding the FDPCP found in this thread for easy convenience. Some members have chosen to pull their FDPCP's down and used calipers to take the measurements already to ascertain answers if their FDPCP's pose any possible safety issues to themselves and others.

We have appreciated all your patience. I know we all want answers and we are getting closer to some, but in the meantime the GTA Staff wanted to bring this matter back up as an update on where we stand and to let everyone know we haven't forgot about this as safety will always be a major concern and we take that very serious.

Here is the link in the Announcement Gate:

http://www.gatewaytoairguns.org/GTA/index.php?topic=99476.msg955714#new

Have a blessed Christmas.

BZ

[bubba zanetti]

An addition was made and to add here two things (Yes, I will sound like a broken record).

1. DEGAS YOUR FDPCP COMPLETELY BEFORE DISASSEMBLY!

2. IF YOUR AIR TUBE IS OUT OF THE SAFETY SPECIFICATIONS RECOMMENDED AT THIS TIME, PLEASE CONTACT FLYING DRAGON AIR RIFLES FOR A REPLACEMENT.

All the information needed again is in the announcement thread.

BZ

[Sprungout]

Not to throw some gas on a smoldering fire, but what if it is a thread pitch issue versus a thread diameter issue? That would explain how our tubes are still wiggly when almost tightened, even when measured up to spec. And if the pitch angles are different, I can't imagine good engagement now matter how deep the threads are. Thoughts?

[ezman604]

Good point. And why I would suggest these airguns be examined by someone with a lot of knowledge in this area. And we have some very qualified folks right here willing to help.
I want to toss out a few more comments and thoughts on this.
This IS a serious issue that needs to stay fresh in everyone's mind that has one of these airguns or have thoughts of purchasing one.
First point....the remains of the "exploding" airgun have undergone professionally unbiased forensic examination. Without the reservoir, no EXACT cause can be determined. But the available parts DID show evidence of strike damage. Whether this damage happened before, during or contributed TO the "explosion" cannot be determined with the info that is available. 
There have been NO other reports of this type of incident.
There have been a few of these airguns examined and found to be questionable as far as safe tolerance.
So we sent our alert out to everyone out of concern for our community. On our part, there is NO other agenda or reason for this alert!!!
We felt that GTA is a leader in the airgun community and had to do something.
We certainly hope everyone with one of these airguns will take the time to inspect or have it inspected to insure it is safe. We cannot MAKE anyone do anything, we can just alert and suggest.
Those of us that give suggestions for safe tolerance and offer remedies if found out of tolerance assume no responsibility. We are merely trying to help our fellow airgunners. What you decide to do is up to you. And YOU assume full responsibility for that.
I hope this was an isolated incident but we cannot just turn away and do nothing, even if we are not responsible for this issue.

[Bob K]

Does anyone have images of the strike damage?

[ezman604]

I'm sure someone does.

[Mikes Garage]

Good point. And why I would suggest these airguns be examined by someone with a lot of knowledge in this area. And we have some very qualified folks right here willing to help.
I want to toss out a few more comments and thoughts on this.
This IS a serious issue that needs to stay fresh in everyone's mind that has one of these airguns or have thoughts of purchasing one.
First point....the remains of the "exploding" airgun have undergone professionally unbiased forensic examination. Without the reservoir, no EXACT cause can be determined. But the available parts DID show evidence of strike damage. Whether this damage happened before, during or contributed TO the "explosion" cannot be determined with the info that is available.

Was a report written by the professional, unbiased examiner?  If so, can it be published here?

Thanks,

Mike

[Mikes Garage]

Is there any more interest in this topic?

I saw today that Dave posted (In the Announcement Gate) that there is now a defined set of inspect criteria that every FD-PCP owner should undertake.

Where can that be found?

Thanks

Mike

[ezman604]

Mike, the checklist will be posted in that Announcement Gate sticky. It should be there shortly. And will also break the rules (this time it's justified) in the PCP Gate.

[RHytonen]

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

It seems to me the inconsistency between the ID and OD surfaces of the REA$ONABLY PRICED caliper's jaws, on the digital calipers available to most people (certainly myself,)
renders our measurements all but useless, in the tolerances needed to determine this issue.

I'm just saying beware of trusting that difference, unless you  (for instance) transfer the measured ID somehow to an OD  so you can use the SAME caliper jaws(internal OR external) for both measurements.
I have long coveted a QUALITY (Starrett or Mitutoyo) analog or "Vernier Dial" caliper.
And a passive (no-dial) caliper for making the above transfer (at least for the interior thread's major diameter) is almost as costly...

[Poorman Plinker]

    Please forgive my personal observation which is only marginally on topic in this thread... First, let me say I learn a lot in this forum  and I too am only human and have bias and prejudice beyond my own personal awareness.
I have been following this thread and "This is what can happen" and find the tone and tolerance levels to be completely different. 
True people have reported Dave to be a "nice guy"  and Alex to be a "arrogant brute" .
This thread has managed to stay on topic while the other degraded to a complaint about a part that was not used in or the cause of the incident.
While Alex was criticized for not establishing a recall... Flying Dragon is not.
A spirit of investigation and cooperation  exist on the Flying Dragon incident but not on "Can Happen"
While bashing and infighting was common in the "Can Happen" thread I am not seeing it here.
So I ask you all: Not, why do we dislike the brute ? That is obvious. But, how can we instill a feeling of cooperation and desire to improve the safety and well being of the entire airgun community on ALL airgun issues .
Again apologies for my naivete and unrealistic desire for a peaceful and united community of users... there must be a way to get closer to that if even if only in my imagination.

[uncle paulie]

Sorry, I just really do not get your point. The staff of the GTA continually strive to maintain an extremely family oriented forum. We are dedicated to "a peaceful and united community of users"(in your words), and we spend countless hours on the site to insure that goal to the best of our ability. The growth we have seen in the last few years has made it difficult(for myself and many of the staff)  to just log on and just enjoy the gates we have the most interest in. Our time is spent carefully going over all of the posts to assure compliance with the rules all have agreed to but are frequently forgotten or ignored. Should you have any specific recommendations about how we may improve our performance, I'm sure they would be considered.  Please feel free to PM any of the staff with your thoughts.

pv

[7624452]

Poorman plinker is a troll. He spouts gibberish, deliberately attempting to make people angry.

[Rocker1]

And I suppose your post here makes it better sir or are you feeding the fire, be careful with what flame you light. David