More DAR bad luck

[Wayne52]

The o rings that came with both of mine aren't good at all, like you say they crack at the seams and chunks break out of them.  If I knew what kind of o rings were on the SS valves I'll bet the right sized one of those would work good, I know they're hard but I don't know what they're made from but they're clear.  The BunaN90duro seem to be just fine for the regulator, on the ends I'm using BunaN70duro and they're holding up really good as well.

[Gertrude]

we took the factory supplied chinese replacement orings, to a local oring supplier today.
They measured the chinee orings and said they were not in spec for either metric or SAE standard.
 in other words, they were oddball in size.
 They tried to match them with good quality alternatives as best as possible, leaning/favoring to thicker or bigger in sizes.

 The new quality orings fit the barrel just fine, but the ones for the regulator still did not fit well.
 We will be returning to this supplier with the rifle parts disassembled for them to measure the grooves in all the parts to determine what will/may work.

 This will also help to determine how far out of spec the grooves are, and it MAY help to explain why the manufacturer put the teflon tape in the grooves too.

[tracker1955]

Gertrude, if you get a chance to go see Ryan at Aim that would be something I'd like to hear about. A face to face with him showing him the problems found could go a long way, although all he can do is report the problems to the chinese manufacturer. I'd like to see them get things sorted out, not good to hear they are using custom or out of spec o-rings. Begs the question what does someone do about o-rings when our rifles are out of warranty in a year. If standard metric o-rings won't fit we're dependent on the ones from the manufacturer through Aim only. That's not cool.

[BigMike1]

The Biggest problem I see is the clearances are far to loose.   The regulator is way to loose in the bore of the air tube the threads on both ends of the tube are on the loose side . I am a machinist and I tell you this stuff way to loose even for 90d orings to do their job. the 90d are just a bandage for loose tolerances.  My 2cents     

[kingrude1]

I thought we had come to the conclusion that  the combination that Wayne found of the 90s on the reg and the 70s at each end of tube were good matches. They did seal my tube, it was my poppet that was leaking. I guess at some point the remaining orings will have to have replacements found, definitely don't want to use their replacements. It is hard for me to see Dar. making it through this bad early period of operation. 3 out of 4 guns not working right out of the box?

[Wayne52]

I got a tracking number coming from Ontario Cal which has to be the parts for my DAR25.  Supposed to be here tomorrow.

[BigMike1]

I thought we had come to the conclusion that  the combination that Wayne found of the 90s on the reg and the 70s at each end of tube were good matches. They did seal my tube, it was my poppet that was leaking. I guess at some point the remaining orings will have to have replacements found, definitely don't want to use their replacements. It is hard for me to see Dar. making it through this bad early period of operation. 3 out of 4 guns not working right out of the box?

I agree ! It is going to be hard on sales even if they get this under control.   What i measured the Tube is to large ID and the best fix would be a new tighter tolerance air tube to reduce the clearance between the regulator and tube... If they wouldnt have asked me to send my rifle back I was going to make a air tube.   

[nervoustrigger]

Ron, just a few thoughts after following the various threads on this issue.  I suppose it’s possible that the material is somehow deteriorating at a breakneck pace…it’s rather unlikely to be because of exposure to HPA but if they were exposed to some incompatible solvent / cleaner / lube, that could explain it.  However based on my general experience, I’m more inclined to think they are failing via extrusion.  A few of the clues were the comments of O-rings that looked spread out like gum or with missing chunks, and that some folks are having luck with harder 90 durometer O-rings (a harder material resists extrusion).  Also, the fact they were packing some of the O-ring grooves with floss is another clue.  Granted, it could be because they mistakenly milled the grooves too deep, but by pushing a greater portion of material to the outside, a larger cross section of material is put between the high pressure side and the low pressure side.  That will buy some time before the material extrudes through the gap but it’s not a good long term solution.
 
If you can post a few closeup photos, we may be able to tell so I’ll keep an eye out.
 
Another thought…isn’t it the seals on the regulator body that are failing most commonly?  Maybe you can get an accurate dimension on the reg OD and the ID where it mates.  The difference should be no more than about 0.010” – 0.012” for a 90 durometer to resist extrusion failure.  Generally it should be quite a bit tighter than that.  Most designs with a 3000psi fill will have tolerances compatible with 70 durometer.
 
But here’s the bad news, if it is in fact extrusion failure, the only practical solution for most folks will be to try a properly sized 90 durometer O-ring.  If that doesn’t hold, a precision fitted backing ring would work but where would you get that?   Plus the groove would need to be widened to accommodate it.  It becomes legit machinist work at that point.

[deerflyguy]

Wouldn't the best repair be for AimSport to recall all 400 guns that are out and replace the regulators with properly manufactured regulators, and other associated parts, that use common sized O rings to enable owners to replace them easily should they fail when out of warranty? Is that too much to ask? After all, we all bought this gun in good faith, assuming merchantability.

[kingrude1]

I think the problem has gone away from the regulator after further inspection. Yes initially the o rings on the regulator were failing and probably still are. But Wayne showed with the duro 90s you can seal that. Some of us were still having leaks after the 90s so we kept believing it was our o rings on the regulators still wasn't sealing. But then we went further into our guns and found those orings had sealed fine but the poppet wasn't seating and it was causing air leaks from the port. I don't know that I heard from anyone who used the 90s that it didn't stop the tube leak.

[Rat Sniper (AKA: PaulT58)]

David, Jason did a good job of explaining the issues with the regulator, and I still believe the regulator is part of the problem.  The Dura90's are holding for now because they are a harder material.  If the regulator fit in the air tube as it should, the original o-rings or the Dura70's should have worked fine. 

I like Bill's idea, but instead of having my gun recalled (i.e. having to subject it to possible damage in transit back and forth to Aim Sports), I'd prefer they just replace the regulator with a properly fitting one with good quality o-rings.  I truly believe a properly fitting regulator and an aligned poppet with the correct spring would probably remedy 99% of the issues being experienced by the folks who have reported problems. 

Since not all have had problems, and some folks have not experienced any problems, a total recall may not be warranted at this point, but I do think parts replacements would be the best way to remedy the problem.  Or, offer the owner the choice to send it back and have Aim Sports replace the parts if they aren't comfortable doing so.  This gun is so simple to work on, I'd just prefer to do it myself.

[kingrude1]

Agreed they are simple to work on and I was really wanting to figure mine out when they decided to bring it back in. With that said, while I have learned a lot from this gun I am extremely disappointed that a brand new gun didn't work out the box and had me spending hours assembling and disassembling trying to get it work like it should have day 1. I know it's a cheap rifle and that is no excuse, so is my  Hatsan Flash and yet all it does is work and does what it's suppose to do, haven't had to put a wrench on it.

[Gertrude]

Ron, just a few thoughts after following the various threads on this issue.  I suppose it’s possible that the material is somehow deteriorating at a breakneck pace…it’s rather unlikely to be because of exposure to HPA but if they were exposed to some incompatible solvent / cleaner / lube, that could explain it.  However based on my general experience, I’m more inclined to think they are failing via extrusion.  A few of the clues were the comments of O-rings that looked spread out like gum or with missing chunks, and that some folks are having luck with harder 90 durometer O-rings (a harder material resists extrusion).  Also, the fact they were packing some of the O-ring grooves with floss is another clue.  Granted, it could be because they mistakenly milled the grooves too deep, but by pushing a greater portion of material to the outside, a larger cross section of material is put between the high pressure side and the low pressure side.  That will buy some time before the material extrudes through the gap but it’s not a good long term solution.
 
If you can post a few closeup photos, we may be able to tell so I’ll keep an eye out.
 
Another thought…isn’t it the seals on the regulator body that are failing most commonly?  Maybe you can get an accurate dimension on the reg OD and the ID where it mates.  The difference should be no more than about 0.010” – 0.012” for a 90 durometer to resist extrusion failure.  Generally it should be quite a bit tighter than that.  Most designs with a 3000psi fill will have tolerances compatible with 70 durometer.
 
But here’s the bad news, if it is in fact extrusion failure, the only practical solution for most folks will be to try a properly sized 90 durometer O-ring.  If that doesn’t hold, a precision fitted backing ring would work but where would you get that?   Plus the groove would need to be widened to accommodate it.  It becomes legit machinist work at that point.

Jason,
Thank you for the excellent explanation. I think we are on the right track here regarding the regulator orings and the ID/OD fit. Unfortunately, I do not have one of the leaking guns in front of me today. They are 40 miles away at my buddies house. I will be shooting with him this weekend and can bring 1 or 2 of them home with me. I will be taking them apart and doing some measurements.
I also have reason to believe the poppet may not be square to the valve, thus causing a valve leak.
I just spent an hour on the phone with my buddy, talking him through the lapping process of the poppet to the valve body.
It appears we are making progress on that issue also.
As I determine more, I will report back. Its going to take me a few days... Simply due to logistics and prior obligations... But I'm working on it.
Thanks for your excellent input.
I may give you a call to discuss some of my findings if that is ok with you.

[Wayne52]

I think the o ring I.D. for the regulator fits the regulator great, as far as how the -117 size fits the tube is too loose, when assembling with the 70 duro BunaN's I kinda figured they wouldn't work but they did work for a few days til they dumped the air, I heard it when it happened.  The o rings weren't extruded probably on account of BunaN being top notch o rings, the air got past them finally and opened them up with no damage to them at all.  That's when I decided to order the 90 duro because I was sure they'd fit much tighter.  Both guns still have the 90duro's that I put in them to begin with, I think they'll last for a long time myself.

The 25 never really had a chance to even break in at all so I had a good look see of the internals early on and since the last time I had it apart the poppet is wearing evenly, hopefully I have no problems in that department, when I had my 177 apart I just had to check out out easily that hammer slides in the delrin sleeve, it amazed me how it slid barely tilting the gun, now that is smooooooth.

The 177 is 50 bucks cheaper at a super bargain price, I think my total cost on that with a coupon I got in my email, it was like $252.95 to my door.   I think this gun could be tuned easily to shoot Nielson slugs too, these little 177's have some serious power capabilities the way they are with only tweeking.  I also noticed there's some room in the TP on the 177 for opening up, it's now .133 and you could go to .150 I think if you wanted to. The barrels on these things are massive like a bull barrel.

All in all after going through the rigamaroll of tinkering and waiting on o  rings I'm still happy with both of them, I've had them both out in the woods hunting with great success, last time I was out with the 25 was the first time I shot at a target at any distance and I was pleased with the way it was shooting.  I had a good run this morning casting 34.5 grain pellets after some tweeking on the mold pins, the skirts turned out about as perfect as I've seen yet and I'm going to try them out in the morning at the state land and maybe do a little hunting after.

[nervoustrigger]

Ron, sure thing.  I’ll be running around so if I miss your call, I’ll ring you back.

[tracker1955]

Good news, got my stuff from Aim and actually got to shoot my rifle tonight. So far it's holding air ok and the new barrel seems to be better as it's not being inconsistent like the first one was spitting pellets on one mag and then stacking them on another. Have it topped with air for the night and will see what it's doing in the morning.


I want to correct something that was said in an earlier post about the regulator, I never was able to get the regulator to seal for more than a mag or two before it would let go and leak all the air out the vent hole just past the front regulator seal. I had no other leaks and my poppet was fine. I tried buna 70's 90's urethane and square o-rings trying to make this thing seal at the regulator and in every case, it continued to fail. They tested the new one they just sent me before sending it and so far it's holding. If I recall there was at least one other member who couldn't get his to seal at the regulator also with replacement o-rings and I think they recalled it as well. I need to get some other pellets to try in this new barrel but so far with no break in the JSB 18.13's are doing best. Want to get some JSB 15.89's to try along with some H&N field target trophy.

[triggertreat]

That's great news Tom!  Maybe it will hold this time.  I do have some FFT you can try.  Maybe we can get together next week.

[oldpro]

Might be time I get my hands on one of these.

[tracker1955]

I say go for it, could use another educated opinion and additional insight.

[Rat Sniper (AKA: PaulT58)]

Might be time I get my hands on one of these.

Yes you should because we'll be needing some performance parts for them soon!  LOL!