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 Post subject: Re: Hipac question?
PostPosted: Thu Mar 26, 2015 10:40 pm 
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Joined: Sun Jan 04, 2015 3:53 pm
Posts: 276
That's a pretty descriptive post Gerard! I have an understanding of most everything you covered. I think I'm gonna order the hipac. This can be my first official project :)

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Cometa lynx .22-hawke sport 3-9x40 ao
Qb 78 .22 (sons)
Crosman 760-tasco 2-7x20
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 Post subject: Re: Hipac question?
PostPosted: Thu Mar 26, 2015 11:05 pm 
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Location: Vancouver
Cool. Glad to help where I can. I hope yours works out well. The guy has a dedicated support forum on network54 which should bring you up to speed on a lot of things about the HiPAC, though he's deleted quite a few comments when they aren't praising the product. I love mine... but only after doing a whole lot of work. His reaction when I said that the 1 extension tube I bought was full of some sort of rust-coloured waxy paste? Didn't happen. When mine leaked and pressurized the front half of my 2240 main tube, necessitating a very careful removal before eventually blowing out the front at 2,000psi? Big deal, so what? Even though it was his 'high pressure' seals turning into chewing gum and blowing out which caused the problem - I went through a few of my own before settling on using Ertalyte plastic fitted carefully to the HiPAC to finally make a lasting seal. He's a jerk. His product is basically sound, not a worry in terms of blowing up, but quality control by whoever he's contracted to make them is garbage and they sometimes work perfectly, sometimes not so much. Still, it's about the only game in town for converting a Crosman to high pressure air without strapping on a Ninja tank, so I'm glad I bought one. Won't be buying another from this guy. I'd prefer to build around some other sort of pressure vessel than deal with him again.


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 Post subject: Re: Hipac question?
PostPosted: Thu Mar 26, 2015 11:45 pm 
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Location: Edmonton
Very interesting comments, GS. I've seen other comments from you regarding the hi pac scenario, but none so condemning. I've also seen related posts discussing the "weak link" features added to the scenario when you build with extensions. Hearing comments from other users on this issue would be most helpful.


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 12:04 am 
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Location: Vancouver
Agreed, substantiating comments would be useful. It wasn't just the extension however. There was the valve seal problem. The fill valve started leaking after a few weeks too. On dismantling for the umpteenth time I found that the tiny O-ring used to seal it was being forced out through the fill valve stem hole. That was after going to 3,000psi. A soft rubber O-ring just isn't up to the job with this design where it's just under compression, no groove. I made a disc out of 95 durometer urethane and it seals just fine.


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 12:22 am 
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GerardSamija wrote:
I love mine... but only after doing a whole lot of work.

That's tuning...it's time consuming.

When mine leaked and pressurized the front half of my 2240 main tube, necessitating a very careful removal before eventually blowing out the front at 2,000psi?

In a 2240, the valve is not sealed to the tube and there is no seal on the hipac threads/crosman tube...it is absolutely IMPOSSIBLE for the 2240 tube to pressurize. Will leak between the valve and tube as fast as the hipac could vent.

Even though it was his 'high pressure' seals turning into chewing gum and blowing out which caused the problem

I don't like the seals either. I use a captured o-ring...never a problem.

He's a jerk.

Alex does have personality issues...he has also been litter on by a lot of people who were wrong and out of line, forced off various forums and generally abused....I'll admit that in his shoes, I would have a couple personality issues too. And perhaps a couple law suites in the works.

His product is basically sound, not a worry in terms of blowing up, but quality control by whoever he's contracted to make them is garbage and they sometimes work perfectly, sometimes not so much.

Basically sound...I agree....I hydrotested one (2240 version) to 5000psi several times without signs of yield. Quality control might be deemed hit and miss, but considering a decent shop rate...rather good value for the dollar...JMO.



I own two hipacs and three extensions...never had a leak or a problem with the units themselves. Seals are something I did have issues with. Went with delrin valve stems and a captured o-ring for the valve/hipac seal and all issues were resolved permanently.

Mine see 3000 psi use as well.

Al


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 12:51 am 
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Location: Vancouver
Well you can say it's impossible if you like, but it happened, so... Here's what happened in more detail, this after using the thing for several weeks up to 2,000psi before finding the time to pull the 2240 apart and swap the seal (his black hard rubber seal or whatever the material is) from the stock Crosman beige one.

- Put the thing together with the new seal and pumped it to 2,000psi.
- Fired some test shots and it seemed okay.
- Remembered I'd have to swap out the hammer spring to operate the valve at 3,000psi so dismantled again and put in that harder spring.
- Pumped to 2,000psi again and tried it. Nothing happened. Apparently the valve was jammed somehow.
- Realised the thing was full of pressured air and had to get rid of that before figuring out how to resolve the valve issue, so as he says on his website I carefully unscrewed the HiPAC just a little to let the air out.
- Nothing happened. So I unscrewed a bit more. Nothing happened. I put the 2240 in a vise with soft jaws and focused my efforts on unscrewing the HiPAC carefully, a bit at a time, until it was out about 6 full turns. It was getting easier... which seemed impossible, as with 2,000psi in there it should be binding the threads MORE not less.
- Kept going, now putting on goggles and ear protection and making sure nothing important was in front of the HiPAC.
- At whatever number of turns it is (around 8 or 9 I think?) the thing had about 1/2 turn left on the threads and got REALLY HARD TO TURN!
- Slowed down a lot. Probably took 5 minutes to unscrew it this last partial turn. It just got harder and harder, until I had to hold the HiPAC Record vise with aluminum soft-jaws, turning the 2240 manually. I'd unscrew about 1/30th of a turn, pause, tighten maybe 1/60th of a turn, let go, then re-position in the vise and clamp then repeat...
- Finally when it was getting ridiculously hard to unscrew it blasted free. I was holding the grip with both hands, hard, but it kicked back maybe an inch. The HiPAC moved forward about the same distance in the vise, leaving aluminum deposited along that much of the HiPAC on both sides where it had rubbed the jaws. The little black plastic seal was gone forever, still haven't found it in my messy little workshop. Blasted forward I presume, somewhere under the drill press stand among all sorts of materials standing in buckets.

Now how did this happen? My theory, and I can't think of any alternative, is that the brass valve body had inflated enough to make a seal against the Crosman main tube, allowing the area in front of the brass valve body and behind the HiPAC to fill to 2,000psi. Boring even a tiny hole into the main tube somewhere around the front of the valve would have prevented this. Removing the front pistol grip frame screw would have been... interesting. Probably would have lost that somewhere, maybe been hit by it. Now I had put the valve body on my little lathe and carved away the threads behind the front cap engagement limit to increase valve volume, just to the bottom of the threads, but perhaps enough to weaken the brass enough to inflate at that pressure. Don't know, as I wasn't inside the thing, but that seems what must have happened. It shouldn't seal, but it did. Alex can call me a liar if he likes and so can you, but it doesn't change the fact that a sound like a loud gun shot meeting a steam train venting its brakes happened when that last bit of thread let go and let the HiPAC jump forward, not quite escaping the vise.

As to Alex' reputation in various forums where he's promoted his products, well, that record is available to anyone who cares to search. He's been banned from a number of websites for his abusive behaviour towards customers. I'm sure he's a great guy in some circumstances. Aren't we all? But man, the guy can be a really awful person at times. His emails to me I should not share out of respect for privacy, but dang, such an attitude. If I treated my customers like that I wouldn't be in business long I think. But then I deal one-on-one with people repairing their instruments. He's in mail order. Makes it easier to abuse some people and get away with it.

Oh, and it occurs to me to mention that I'd lubricated the HiPAC threads with white lithium grease, which would explain the seal there. Standard practice for an old bike mechanic. A fine thread under high stress should be lubricated. Steel-on-steel is not good. So the threads sealed, as apparently did the valve against the Crosman cylinder, which I had polished quite smoothly. That was for smooth and consistent hammer travel. But I polished the inside of the whole tube so yeah it made a good surface against which the brass could seal. And I'd polished the valve brass... Is it wrong to make metal parts finished? Does the Powermax HiPAC depend upon crudely finished parts surfaces to work correctly?


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 12:59 am 
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So, are you saying, Al, that the hi-pac solution, as simple an alternative as it seems at first glance, is not for the uninitiated in the PCP world? I do know that some time ago I purchased a 2240 (original tube) that included a hi-pac (but not installed). When I passed it by my "main man" in technical matters (and others), He told me the pistol had not been reinforced for HP use. He added a couple of supporting screws and said. "Now it's ready to accept that hi-pac tube. That's when I first got the sense that HPA is nothing to mess with, and quick HPA solutions are not for the uninformed.

Agree?


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 1:35 am 
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Location: Alberta Canada
Gulp.....burp... :drinkers: yes your right there Murray. Err on caution and a little over engineering can not hurt in keeping one safe. 8)

As for your ordeal Gerard IMHO. Did you had the piercing needle of the stem still attached? If so, this is what happened. The hammer strike lodged the needle tip into the HI Pac which caused it to seal.
As you have described would have been the case. As your unthreading of the Hi Pac had gotten considerbly harder to turn is where the needle was being unjamed from the extention. And the rest of the stem was jammed against the vale interior. The needle turned with your unscrewing of the Hi Pac. The pressure from how you explained upon unscrewing extracted the needle tip.

I have a Hi Pac pistol upon my bench. Just testing my theory and yes that would be about equal distance of threads and bottoming out of the peircing needle being stuck in the the HI Pac extension by. Close to 0.040" not counting the trim off the vallve thread end you had done for extra internal area. Hence I drill them out if the client wants the ability to revert back to Co2 caplets. :idea:
As for your theory of brass expanding. :shock: Wouldnt happen the body would have cracked if that had actually happened. Yellow brass is way too brittle to expand.

But then :drinkers: ...burp....its Just MY Opinion..... :mrgreen:

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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 1:45 am 
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Location: Vancouver
Okay, cool. I think that's the answer and it makes much more sense. I'd been trying to imagine brass expanding like that and from my experience working that metal it just didn't make sense, but I couldn't think of anything else. YES, I did still have the needle in the valve at that time. It wasn't until some time later that I cut it off, then later still made a new poppet using nylon and an old drill bit. That one works very nicely as it's carved to mate exactly with the curves of the inside valve face. I wonder why he'd make the HiPAC exhaust port such a snug fit with the CO2 puncture pin? Seems what must have happened is that my one test shot which didn't fire managed to push the pin right into the HiPAC opening and jam it there. So weird. If I were making the HiPAC in light of that possibility I'd make the hole just a few thousandths larger to prevent such a jam.

As to the question regarding reinforcement, yes, I've done that as well. Drilled and tapped for a pair of 10-32 set screws, one on either side of the valve just above centre. The single tiny bolt in the bottom was bending and stretching the hole in the main tube. Even enlarging it and re-tapping to 10-32 it was showing distortion at 3Kpsi. With the extra set screws it's solid. Just have to be careful about exactly where you put them or your valve will be ruined.


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 1:55 am 
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Being that it is a common occurance that someone gets a Caplet jamed upon a needle. After I read exactly what happened and what you did. Being I have a 2240 and HI Pac upon the bench just dismatled, was gonna do it up tomorrow. Was a test to the theory. I just have always drilled them to allow better flow both valve body tip and Hi Pac.

End result you didnt get hurt. :D

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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 5:57 am 
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Whitewolf wrote:
End result you didnt get hurt. :D


Yes indeed, good job at the careful disassembly. Getting stuck with high pressure inside a gun is big worry of mine, there's a lot of potential for bad stuff there. I was trying to imagine how this scenario could have happened - I hadn't thought of the striking pin. I removed them from both my 2240s and went with a fixed hollow piercing pin, so I'd didn't think of that. Do the HiPac installation instructions require the pin to be removed? If not, it would seem to be a fairly major design flaw that the pin can jam like this.

Jim


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 6:41 am 
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I have also had the piercing pin jam in the hipac when I first recieved it. I was lucky however, that mine let go after firing a few dead shots.
The "special" seals he sells are garbage, don't bother buying them. And although possible to fill to 3000 psi, I find there are too many components down stream to address, to make the extra few shots practical. 2000 psi in my disco gives me 45 to 60 shots at or above 500 fps. A heavy enough hammer spring to open the valve at 3000 psi will hurt your bolt finger and will snap off your bolt handle eventually. I realize there are solutions to the issues associated with 3000 psi, but the OP wanted a simple conversion. Later the curiosity factor will take hold and he will again look to us for help, one mod at a time. For now he just wants to get off C02.
Personally I love my hipac, but I dont know why he didn't design it to screw directly to the valve by simply removing the end of the valve and screwing in the hipac. Then there would be no need to put extra pins to secure the valve.
Good luck with it all. Cheers

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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 11:14 am 
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Joe's summed it up nicely. The HiPAC is made to be easy to swap with CO2, making going back and forth as easy as just using CO2 alone. Much of the difficulty can arise when pushing it to 3,000psi. Seals blowing out, heavier spring required with reinforced cocking knob more or less essential (see my hacked 2240 thread for one solution - no pain and no fatigue on the parts now), and the valve mount being insufficiently strong for the hard pressing needed to seal against it add up to a daunting set of mods. But if you run it at 2,000psi it should be fine. Reducing the transfer port size might be enough to make the resulting shot string a bit more sensible. Alex's own one demo video - https://www.youtube.com/watch?v=MqBFtRT4Qx0 - shows the main problem with just pumping to that pressure and shooting: the huge increase in initial velocity puts the 2240 WAY over the legal limit, then it starts dropping off sharply until after just a few shots its hundreds of feet per second slower. Halving the TP size might fix that, but refining the velocity curve such that it becomes meaningful for consistent shot-to-shot point of impact requires other mods.


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 9:29 pm 
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Edmonton<500 wrote:
So, are you saying, Al, that the hi-pac solution, as simple an alternative as it seems at first glance, is not for the uninitiated in the PCP world? I do know that some time ago I purchased a 2240 (original tube) that included a hi-pac (but not installed). When I passed it by my "main man" in technical matters (and others), He told me the pistol had not been reinforced for HP use. He added a couple of supporting screws and said. "Now it's ready to accept that hi-pac tube. That's when I first got the sense that HPA is nothing to mess with, and quick HPA solutions are not for the uninformed.

Agree?


Anything that can hurt you DEMANDS respect...high pressure gases certainly fall into that category. There are (correction...WERE) recommendations on the hipac website to beef up valve retention. Bought mine used so I'm unsure whether the instructions to upgrade the screw are included with the actual unit.

Checked his new website....cannot find the recommendation to beef up the valve retention screw... :? It WAS on the old website.

JMO, but it should come with the instruction to upgrade the screw...and the 20 cent screw. Have sent out a few of them to folks that needed them and had trouble finding good ones. For a few dollars more, a delrin valve stem and bonded washer/dowdy seal could be included, which would eliminate ALL the issues some folks seem to have.....but then it would be a dedicated pcp...no switching back and forth. Truth be told, I don't think I've ever heard of anyone actually switching back and forth. :)

Hipac IS a simple solution and works well. As far as reinforcing the valve retention, that's a good idea...Crosman never intended this mode of operation and thus did not setup the 2240 for it....that's left to you. Everyone starts "somewhere" when going pcp...this is as good as any if done properly. At 2000 psi, the stock valve stem and seal worked fine for me, but as ever YMMV.

At any rate, if you're interested, you can check here...http://www.network54.com/Forum/275684/t ... pac....the math is laid out for you to judge on your own.

Al


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 Post subject: Re: Hipac question?
PostPosted: Fri Mar 27, 2015 10:00 pm 
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Thats an old read. But none the less worth of information to those that are new and dont know. :wink:

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