Sealing for inlet valve?

[lagfish]

Hi,
I took apart my Cyrano Evo 70 because I was curious and I'm not sure how the rear inlet valve seals or maybe I've lost an O-ring? In the diagram below, there needs to be a seal in one of the two places. I did notice there was a raised piece of plastic on the housing - perhaps that is the seal when you tighten down the inlet valve against the inner barrel?

Also, has anyone experimented with polished stainless steel or some other material for the barrel? Seems like we can reduce the friction - but that probably doesn't account for much of the power loss anyway.

 

[popgun pete]

There is no "O" ring, that ridge is the "seal", so don't scratch it!.

 

[lagfish]

There is no "O" ring, that ridge is the "seal", so don't scratch it!.

Is there a torque setting for it? I probably shouldve measured it when taking it apart...

 

[Diving Gecko]

Yeah, the first time I took apart my first pneumatic, I was wondering if I had lost the o-ring, too.

In reg. to SS barrels. Some Russians and Ukranians are very fond of them. They say it lowers friction dramatically, but we have discussed it here a few times and others say that once the piston is moving, the friction is negliable. I am still undecided on whether giving it a try or not. My main issue is practical - the Ukranians use 12x14mm steel barrels, but I wont to continue with my 13mm ID setup but I haven't been able to find any polished barrels in that size.

 

[lagfish]

Part #89785K844 on McMaster-Carr might be what you need. You'd have to call them to find the exact dimensions and tolerances but it's close to 13mm.

I'm thinking about extending my Cyrano 70 to a longer version with a steel barrel. I found a carbon fiber tube with almost the exact dimensions as the outer barrel

 

[popgun pete]

The Russians and Ukrainians spearfish in rivers and lakes and there can be a lot of suspended silt and sand in the water column kicked up by the currents. When loading their guns this abrasive soup goes down into the inner barrel and over time will score it ruining the seals. Stainless steel is more resistant to scratches and by using it the guns can have a longer service life. The downside of stainless steel is it can rust in places giving rise to pits in the metal, something you don't get with aluminium. Anodized aluminium can be hard like sapphire, but the anodized surface is very thin and a quartz grain will slice right through it. Aluminium alloy barrels are OK if you keep all sand out of them and wash the gun in freshwater after each use. How do I know this? Well I asked my counterpart in Russia about it.

 

[lagfish]

Is there a place in the US I can buy a replacement barrel for the Cyrano Evo in a week or so?

 

[popgun pete]

Is there a place in the US I can buy a replacement barrel for the Cyrano Evo in a week or so?

Try Spearfishing World as they have pneumatic spare parts. While you have your "Evo" apart maybe you could photograph the front of the power regulator block and its rear as well as we have not seen them in any photos.

The reason for this request is explained here: https://forums.deeperblue.com/threa...irage-secondary-pumping-barrel-system.106994/

http://www.spearfishingworld.com/spearfishing-gear/speargun-parts/pneumatic-speargun-parts

 

[lagfish]

Here they are:
Let me know if you need any more photos while I have it apart

 

[popgun pete]

Here they are:View attachment 42988 View attachment 42989
Let me know if you need any more photos while I have it apart

Great, as the non-return valve was where I thought it was as can be seen here when I was checking the variator system out. My thoughts are the variator is a bit of a gimmick if you read my last post on the "new" Mirage thread.

When I take a new type of gun apart I photograph everything as a reference is always handy to have, plus Mares never released the parts diagram for this model, thus up until now we only had the 3D Graphics model on the video where even rather ordinary things can be made to look good!

 

[popgun pete]

Contrary to what was stated in the video, the "Cyrano Evo" transfer port looks to be bigger than 6 mm diameter when looking from the front end. Here I have prepared a direct comparison photo montage.

 

[Diving Gecko]

Could you measure the offset of the barrel, too? If you have some calipers, that is.
We just need the shortest possible distance from the inside of the "barrel hole" to the outside of the bulkhead. (Though judging from the pix it looks like the Mirage has more of an offset.)

 

[Diving Gecko]

For the outer reservoir, I have carbon fiber on all of mine. 38mm ID x 40.5mm OD, custom made to these specs for me affordably in China. If it is well made, 38mm x 40mm, like the original alu, might be totally fine, too.

 

[Diving Gecko]

Part #89785K844 on McMaster-Carr might be what you need. You'd have to call them to find the exact dimensions and tolerances but it's close to 13mm.

I'm thinking about extending my Cyrano 70 to a longer version with a steel barrel. I found a carbon fiber tube with almost the exact dimensions as the outer barrel

For me, that one wont work - for you it might, though I am hestitant about it.
My guns use 13x18mm barrels. Yours use a 11x16mm barrel and while the pipe in the link is about 10.9mm ID, the wall thickness is only 0.9mm. Might not be a problem but remember, you would need to thread both ends and add adapters (could be from alu) to get to 16mm. So, I am just wondering if 0.9mn wall is enough to thread into. Actually, that's how the Ukranians tend to do it and they just use 12x14mm SS so maybe you can pull it off.
(I am not saying you should find some 11x16mm stainless as it will make your gun sink).

Examples of Dima, a Ukranian custom manufacturer's, work here:

 

[popgun pete]

If you spear in the shore break on a gently sloping shore as schools of fish zip through then you will have sand being churned up to contend with, but otherwise the alloy barrel will be fine. Stainless steel barrels have a weight penalty, but if you spear in inland waters with the water moving through stirring up the bottom then the only choice is stainless steel, otherwise you change guns more frequently as the barrel wears out. Of course if spearing is practised infrequently, then any gun will do as few shots are being put through it.

You are in the USA, so are you diving in the ocean or in a lake? In Australia for example freshwater spearfishing is totally prohibited, in the distant past it was allowed, but when fishermen groups demanded that the sport be banned the fall-back position was we could spear in the ocean. Estuaries and enclosed water bodies are forbidden, which may be just as well as careless yahoo powerboat operators could conceivably give you a propeller haircut.

 

[lagfish]

For me, that one wont work - for you it might, though I am hestitant about it.
My guns use 13x18mm barrels. Yours use a 11x16mm barrel and while the pipe in the link is about 10.9mm ID, the wall thickness is only 0.9mm. Might not be a problem but remember, you would need to thread both ends and add adapters (could be from alu) to get to 16mm. So, I am just wondering if 0.9mn wall is enough to thread into. Actually, that's how the Ukranians tend to do it and they just use 12x14mm SS so maybe you can pull it off.
(I am not saying you should find some 11x16mm stainless as it will make your gun sink).

Examples of Dima, a Ukranian custom manufacturer's, work here:

For your 13mm, here's a part that might work:
89895K762
It's a smoothbore seamless tube, so the roundness/smoothness should be very good. If the diameter is off by a bit, you can always machine a custom piston.

 

[lagfish]

If you spear in the shore break on a gently sloping shore as schools of fish zip through then you will have sand being churned up to contend with, but otherwise the alloy barrel will be fine. Stainless steel barrels have a weight penalty, but if you spear in inland waters with the water moving through stirring up the bottom then the only choice is stainless steel, otherwise you change guns more frequently as the barrel wears out. Of course if spearing is practised infrequently, then any gun will do as few shots are being put through it.

You are in the USA, so are you diving in the ocean or in a lake? In Australia for example freshwater spearfishing is totally prohibited, in the distant past it was allowed, but when fishermen groups demanded that the sport be banned the fall-back position was we could spear in the ocean. Estuaries and enclosed water bodies are forbidden, which may be just as well as careless yahoo powerboat operators could conceivably give you a propeller haircut.

To be honest I don't spear that often - maybe a few times a year. The question about a stainless barrel was just out of curiosity. There are some states in the US and provinces in Canada that are less restrictive for spearfishing.

 

[Diving Gecko]

For your 13mm, here's a part that might work:
89895K762
It's a smoothbore seamless tube, so the roundness/smoothness should be very good. If the diameter is off by a bit, you can always machine a custom piston.

I appreciate it, but though my guns are heavily modified already, I still like to keep as many parts interchangeable between them as possible - pistons being one of them. Also, I am based in China, so if I do go down the SS barrel path, I would likely source locally.
Finally, while I like what UBL/Dima does with the 12mm barrels, I like to stay at 13mm for my Mirages so I don't have to increase the pressure to get the same force on a smaller piston. Mirages already run at higher pressures than most other traditional pneumatics.

That said, at some point in the future I do see a stainless steel or titanium barrel in one of my guns, it would definitely be a natural progression of my tinkering

 

[popgun pete]

The most expensive "full-titanium" pneumatic spearguns from Russia and the Ukraine all use stainless steel inner barrels, Titanium may be good for many things, but not as an inner barrel. An associate of mine recently purchased one of those titanium "Zelinka" operating system guns and it has a stainless steel inner barrel; considering the very high price paid for it the choice of a stainless steel inner barrel is not an economy measure!

Here is another example, but this one uses a ball type sear and is one of the "elite" models.
http://www.doroganich.ru/product/108/

 

[Diving Gecko]

Well, could be. But just because the gun is already expensive, I don't think it can be said with 100% certainty that they are not trying to reign in costs.
If cost was not an issue then, depending on the temper and the grade, TI does seem to be a viable alternative to e.g. 316. TI has super corrosion resistance in, high hardness and it can be polished to pretty much a mirror finish, too.
But I do think getting it in the sizes needed might get very, very expensive. I think even Dima told me that in real life it really just doesn't make much sense to use it for a shooting barrel - as stainless is already very good and, he feels, much better than alu. The only reason would be to save weight but if the outer reservoir has enough volume to balance the gun, then no need.

On a related note, I have just found a local source for 16x13mm (OD x ID stainless steel tube (316L BA). BA stands for 'Bright Annealed" which gives it quite a smooth surface already - like what you would find inside a dish washing machine. It could perhaps be polished to even more of a mirror finish.
But in an app. 130cm length it would weigh about 700g vs. app 425g for a standard alu barrel (18x13mm). In comparison a TI barrel (16x13mm) would weigh about 420g (though I haven't found that size yet). The steel barrel could probably be turned down on a lathe a bit in strategic places to lose some weight but it only really makes sense in a gun with a custom, bigger volume reservoir. So, I am not discounting it all together, just yet, as I am still thinking of making just such a reservoir.
But no need for me to take it further down this thread. Not here and not now.