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David, can you see, is there some tapered seat for the O-ring? How long is it, approximately... 5, 6 mm?
That make sence.
Most of my shooting is on
Scuba. I'm going to do some
Test in the pool when it warms up.
I guess I can set a target and see witch
Way has more power loading above water or
Below.
I have looked, but can't tell. To the naked eye it doesn't look tapered, but if the taper is really small, maybe I would be able to tell from just looking anyways. I don't have calipers here and the ones I have at home couldn't measure it anyways since it is in a deep recess.
Seatec says to open the muzzle one full turn before firing and since the thread is really coarse it means the muzzle opens quite a bit, maybe 5-6mm. Definitely enough to let the whole ring escape from its seat and into the bigger area in front of it.
D.
Why do you always.
Write your sentences
In this really odd
And slightly annoying way.
It really is
Rather strange
Maybe it's a symptom of spearing on scuba?
That would explain
a lot.
That cone, if there is a cone, could be about 8 deg. In that case you might notice it. But it is possible there is no cone at all. In that case loosening the nut would not have effect except if the nut is compressing the O-ring.
I am pretty sure that the nut is indeed compressing the o-ring. The o-ring is oversized on the internal dimensions (6.75mm spear). It is also oversized in regards to the recess it sits in, so it compresses a bit from just being in the recess. If the o-ring is out of the muzzle (imagine a spare o-ring) and sits on the spear it wont sit tight, there's a gap. That gap is closed, but not firmly, when the o-ring sits in the muzzle and spears is inserted with muzzle not screwed in tight. But when the muzzle is screwed tight the o-ring puts more force on the spear leading me to believe there is a fair bit of compression going on.
At least that's how I remember it. My gun is with a friend now and I only have the fist muzzle which was sent to me by mistake (wrong thread size for a Seac).
D.
O-ring should not be compressed axially between the nut and the opposite surface of muzzle wall, just radially when the shaft is inserted.
Why do you always.
Write your sentences
In this really odd
And slightly annoying way.
It really is
Rather strange
Maybe it's a symptom of spearing on scuba?
That would explain
a lot.
Lol!!! Most of the time im diving.
And I'm not afraid to use a air gun.
Are you getting another air???
I would rather.
Chew off my own arm
than ever use an
air gun rofl
Pete, where did you find this information, that there is a tapered seat for the O-ring? I missed that information. Some time ago, in a post I supposed there was a taper for O-ring in Evo-Air, but actually I do not know if it is ture. The early version of Evo-Air had not tapered seat. But if the new version has it, your proposal might be a solution for easier loading. The problem will be to determin the optimal depth for O-ring for 6.75 and 7 mm shaft. This is not an easy task as it seems. You can not rely on "feeling". Only reliable way is applying measurement and O-ring calculation.
Your are right about,some sort of safety device.
I'm looking at the bottom part of the Giga press,
That would be good just to hold the spear in place
While hand loading,but for my 90 at 27 bar, don't need
It. Will look into it,if a get a bigger one air 120. It's to bad
You lost interest in it(got scared)it looked like you we're very
Happy getting it.
I only figured it was a taper as it would be better than crushing the "O" ring. I have seen "O" rings mounted in tapered seats before. It was either that or a stepped change in seat, but I thought that unlikely as the "O" ring might catch on an angle going into the smaller seat diameter.
Yes, I agree with you, but it is likely there is not a taper. David could not see any taper in his kit. I asked the designer few times but he had not answered to me. I suppose he wished that be a secret? What a stupid secret! I had similar situation when was asking for O-ring size for Tovarich to help an Australian guy. At last Sub Fireman gave me the answer, and no one from Spanish forum. With the thickest shaft O-ring is much over compressed so loading effort must be unnecessarily high. And shooting speed could not be noticeable higher than with any other kit. On other hand it sounds nice to have one kit for a range of shaft diameters, but is it worth? I would not make such design.
You should check that with another muzzle too. O-ring is 7 x 3 mm.Just played around a bit with a 7mm spear and the left over Evo-Air kit that I have. But I have not been able to replicate what I thought I observed in the water.
I could not sense that the friction was noticeably more when inserting the spear into the loosened muzzle as opposed to a fully tightened one.
I did notice that the O-ring must be very, very close to 7mm I.D, perhaps it is 7mm exactly.
So, I am sorry about this but either my observations in the water were wrong or this muzzle behaves differently than the setup on my gun.
David
Hi Pete and Tomi,
The small rod in the box is actually a screw-on tail end for a spear. But I am not sure why it is there? Maybe for 7mm normal pneumo spears, as they have a small step on the tail end to hold the washer for the slider, right? With this flush end one, one could use the original spear if it was 7mm.
I'll try to look at the insides of the Evo-Air kit again today, but as said, I could not identify a pronounced taper, but there is a step.
I was actually beginning to see one benefit to the Evo-Air when loaded per Tomi's instructions. As I see it, keeping the seal open when inserting the spear is a good way to make sure there is only what Pete called the accommodated amount of water in the muzzle. It should minimize the risk of water being pushed behind the piston.
But of course, the product is not perfect as per the earlier posts outlining 2-3 ways of making an improvement to reduce the friction on loading.
And this is a bit vain, but if a manufacturer one day wants to spend a few more bucks on a kit, they could make a better anodizing of these kits. Both the Evo-Air's and the One-Air's anodizing is very thin. They are def not hard anodized and I just hope the aluminum used is a good marine grade one.
I have used some very nice underwater housings for DSLRs and the hard anodizing on one of them is really, really hard. It has stood up surprisingly well with a lot of tough use where the Evo-Air's anodizing is rubbing off from light use - even the knurling nut from just turning it.
D.
Hi Pete and Tomi,
The small rod in the box is actually a screw-on tail end for a spear. But I am not sure why it is there? Maybe for 7mm normal pneumo spears, as they have a small step on the tail end to hold the washer for the slider, right? With this flush end one, one could use the original spear if it was 7mm.
I'll try to look at the insides of the Evo-Air kit again today, but as said, I could not identify a pronounced taper, but there is a step.
I was actually beginning to see one benefit to the Evo-Air when loaded per Tomi's instructions. As I see it, keeping the seal open when inserting the spear is a good way to make sure there is only what Pete called the accommodated amount of water in the muzzle. It should minimize the risk of water being pushed behind the piston.
But of course, the product is not perfect as per the earlier posts outlining 2-3 ways of making an improvement to reduce the friction on loading.
And this is a bit vain, but if a manufacturer one day wants to spend a few more bucks on a kit, they could make a better anodizing of these kits. Both the Evo-Air's and the One-Air's anodizing is very thin. They are def not hard anodized and I just hope the aluminum used is a good marine grade one.
I have used some very nice underwater housings for DSLRs and the hard anodizing on one of them is really, really hard. It has stood up surprisingly well with a lot of tough use where the Evo-Air's anodizing is rubbing off from light use - even the knurling nut from just turning it.
D.
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