Taimen - Russian pneumovacuum speargun

I just discovered that there is now an Acrobat version of the "Taimen" 2011 handbook downloadable from the web-site. Content is expanded on the previous 2005 version and has some extra photos, including a close-up of the spear tail. In Russian, but the diagrams and illustrations allow the content to be understood. http://apox.ru/taimen?start=3

Copy the link and paste into your URL address bar if it does not work by just clicking on it.

Here is the assembly diagram with the part numbers from the components list added plus the various "O" ring sizes. Note that a rubber ring to keep debris out of the port in the handle moulding where the power regulator shaft enters is listed in the operating manual, but not shown here.

Note that the annular nut (part 10, 20) on the above diagram is both internally and externally threaded. The inner barrel's threaded front end screws into the annular nut's inner thread and the annular nut's outer thread in turn screws into the thread in the rear of the muzzle. In the "Taimen" speargun the muzzle is both a nose cone and a muzzle combined as a single unit, whereas we usually see these as separate parts. The vacuum muzzle seal for the spear and the associated shock absorber parts are all inserted from the rear of the muzzle. As there are no muzzle relief ports the shock absorber (damper) body (part 8, 18) sits inside the front end of the inner barrel which keeps it aligned to the longitudinal axis of the barrel and the muzzle. The large section width 21x11 mm "O" ring (part 61) is needed as there are two concentric threads in the fully assembled muzzle to be sealed off due to the use of the annular nut connection between it and the inner barrel tube. The muzzle is drilled with eight longitudinal blind holes arranged in a ring on the front face to both lighten it and provide four alternative locations for the slide action carabineer which uses the larger set of holes connected to the milled slots on the forward section of the muzzle body. Alternative positions for the slide (part 11, 21) are needed as the orientation of the muzzle when it is fully tightened up depends on where the screw thread starts on each individual muzzle. It is not possible to know in advance which of the four holes will end up on top of the muzzle until the gun is assembled, then the slide can be fitted.

I learned only a few days ago from my contact in the Ukraine the news that the designer of the "Taimen" pneumo-vacuum speargun, Mikhail Dmitrievich Kuznetsov, had passed away. I did not post it then as I wanted to verify this news myself before adding some comment here.

Sadly this is in fact true and some public responses can be found here on the Web at http://forum.tetis.ru/viewtopic.php?t=64248&sid=2e74df9c644a0cb8ebe47d3b5fc86122 and here http://podvoh.ru/ipb/index.php?showtopic=11037. There is also something about his passing on apox.ru, but the auto translate is not working there for some reason when I last checked.

My condolences to family, associates and friends.

The late Mikhail Dmitrievich Kuznetsov with what appears to be an early version of his speargun. I believe that he was only 52 when he died, far too young! He looks very happy here emerging from the water.

If one looks closely at the "YouTube" video mentioned by Tromic in post #30 of this thread then it is possible to catch a glimpse of the air bypass holes in the rear body of the "Taimen". At around 3 min 14 seconds into the video the rear body is pulled out of the outer body tube and for an instant four small holes come into view as one looks obliquely into the front face of this component before it is placed on the work table. I assume that there are eight longitudinal holes arranged in a ring, although we never look fully end on into the rear body in this video to see all of them. As the gun being dismantled is the single power "PV" version, or should I say "PVM" as the front tied spear "PV" version is no longer produced, there will most likely be one hole (maybe more) eliminated from the "PVMR" (or "PVRM") version to avoid a longitudinal hole running through the power regulator shaft position in the rear body of this variable power model. The single power gun has no such bore hole drilled in from the side of the rear body, although I don't know how the ring of longitudinal holes interact with the bore that the cylindrical sliding sear operates in which is in front of the power regulator position. Airflow details from reservoir to inner barrel and around or through the port in the cylindrical sliding column sear (which serves as the catch for the piston tail) is something that I have yet to find any information about.

Note that some of the longitudinal holes may be blind drilled, for example a hole cannot go through the actuating pin on the bottom of the cylindrical sear where the trigger pushes up on it.

The spear tails on the "Taimen" speargun shafts have a small diameter end projection which fits into the matching hole in the face of the piston, but unlike most Italian pneumatic guns this projection does not appear to be tapered, instead being just a short cylinder with a rounded tip at the rear. From my reading of some Russian forum discussions it seems that the spears are held in the gun only by the vacuum created when pushing the spear into the gun. That means that atmospheric pressure (or ambient pressure at depth which will be greater) has to act over the cross-sectional area of the spear shaft and apply sufficient force at the muzzle opening to stop the shaft falling out of the gun with the muzzle pointed downwards. Assuming that the pressure in the charged up to shoot gun's inner barrel is zero, or very close to it, and calculating the shaft cross-sectional areas for the various spear diameters used which are 6.5 mm, 7.0 mm and 8.0 mm, we obtain areas of 33.18 sq. mm, 38.48 sq. mm and 50.26 sq. mm. Thus the maximum shaft weight, including accessories, that can be supported is 343 g., 398 g. and 519 g. respectively. For a 5/16 inch diameter shaft the figure would be 511 g., providing a comparison to the 8.0 mm diameter shaft as they are close to the same size (the "Taimen" gun uses only metric shafts and they have to be matched to the gun which is specifically manufactured to use one size).

So one way of checking that an inner barrel vacuum was present after cocking the "Taimen" gun would be the shaft not falling out of the muzzle, provided that the entire projectile weight was under the maximum that could be supported by the vacuum (there may also be some help with friction from the muzzle rubber seal acting on the shaft). An advantage, although probably small, is the shaft does not have to jerk free of the piston when it leaves the gun as there is no "conic friction" holding it in as is the case with conventional tapered spear tails. According to the forums the spear tip could catch on something when grubbing amongst weeds on the bottom and then the shaft can be pulled forwards in the gun, but it would be a simple matter to push it back in, provided that it was not pulled clear of the muzzle seal (which is fixed in place) and did not admit any water into the gun when doing so.

Possibly standard pneumatic spearguns converted to pneumo-vacuum operation could dispense with their tapered spear tails (using cylindrical tails instead) and just rely on this vacuum effect to hold the spear in the gun. The mass of a Cyrano 110 cm threaded end spear of 7 mm diameter is 330 g. with another 35 g. for the tip, which gives a combined mass of 365 g. and as a mass of 398 g. can be supported (see above), so there is a small margin, provided that the vacuum in the inner barrel is good.

Friction from the muzzle rubber seal acting on the shaft is maybe in a range 200 - 400 g.

trromic said:

Friction from the muzzle rubber seal acting on the shaft is maybe in a range 200 - 400 g.

Click to expand...

Even when the rubber seal and shaft are both wet?

popgun pete said:

Even when the rubber seal and shaft are both wet?

Click to expand...

Yes, because O-ring in muzzle is compressed 10 - 20%, depending on the vacuum barrel system.

I have ordered a "Taimen" gun and hope to use it this season in the often weed-choked inshore areas here which have an undulating bottom of eroded beach rock, flat sandy patches (with sometimes exposed underlying pebbles), basalt rock reef outcrops and intervening meadows of seagrass. I have destroyed many speartips in this location, so have selected a power regulator equipped model. The "Taimen" should float, unlike my other small guns which don't. To keep the postal package small I selected a 600 model, plus I don't need another long pneumatic speargun. Correspondence (mainly in Russian) with the company went very well and the person at the other end was very helpful in offering suggestions. Now the gun and its accessories just have to arrive. I ordered extra spears and tips as lost spears are always a possibility. Ironically I have found a number of lost spears on the bottom, but never the spears that I have just lost. The same goes for dive knives, although once I found a shiny new knife on the bottom which when I looked down at my knife sheath was in fact my knife, it had fallen out without me noticing some minutes before.

Awaiting your new gun like I am getting it myself.

I am excited too.....

I have now translated the 2011 version of the "Taimen" instruction manual/handbook for operating from Russian into English. The only way to do it was to retype it all in Russian (a big job) as the original pdf file does not allow the text to be sucked out of it and I don't have OCR for Cyrillic text. I put the resultant typing job page by page into an on-line translator and then weeded out the various errors which still tend to occur with material of a technical nature. The result, with images, has turned into a large file (1.96 MB), so I will just put some of the text up if anyone is interested.

Nice work Peter! Are you still awaiting your new gun?

tromic said:

Nice work Peter! Are you still awaiting your new gun?

Click to expand...

Yes, it has not arrived yet. I will let everyone know when I receive it.

Still cant wait, its like Christmas's might come early for you...

While waiting for my gun to arrive I had a look at the Taimen photo album expecting to see the usual photos of fish and happy users, but an examination of additional pages showed many close-up details of the gun in a dismantled condition: http://apox.ru/forum/gallery/album/1765-taimen/

No need for me to take any interior photos of my gun as everything seems to be shown here in great detail! I never thought to look here before, but many questions are answered in these images, many were taken by the author of the gun. Tromic (Tomislav) receives a mention for his line slide.