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Tomba - All in One barrel sealing

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
Pushing the "O" ring into place is the problem with these last two designs, although capping the "O" ring inside the closed up line slide is a nice idea once the shaft flies to the target. A soft split partial cylinder that could be interposed for loading and which could be pulled off the shaft before final rigging may work, you would have to store it somewhere and not lose it.
 
popgun pete said:
Pushing the "O" ring into place is the problem with these last two designs, although capping the "O" ring inside the closed up line slide is a nice idea once the shaft flies to the target. A soft split partial cylinder that could be interposed for loading and which could be pulled off the shaft before final rigging may work, you would have to store it somewhere and not lose it.
Click to expand...

Yes, Pete! You are right! There would be a problem to have the O-ring reliable in sealing place without such a "tool" as you suggested. Until now I would say Tomba700 is the best solution, most reliable, simplest, and easy to use. Of course TombaF700 is also excellent but it is "free shaft".
Tomba7N1 might be good too, but it is not very convenient to check and change the O-ring, the inner one, inside the steel stop ring. Tomba7N is also a possible solution, but scratches in ertacetal slider might cause pure sealing condition. Tomba7: http://forums.deeperblue.com/pneuma...mba-all-one-barrel-sealing-34.html#post864319
also would not work as supposed to. Because it uses 16 x 8 x 4 mm O-ring it would operate only in shallow water, just few meters depth. On higher depth water pressure would prevent O-ring to move in front position and after shooting the O-ring would be damaged by the shaft tail stop diameter step. I think similar problem might be with free shaft Evo-Air on higher depth, maybe more than 10 m. Evo-Air would still operate on higher depth, but not with zero friction as it was supposed to.
 
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This was missing between Tomba7N and Tomba7N1:



More complex than Tomba7N, but O-ring is shielded in stainless steel housing. It is also easier to inspect or change the O-ring than with Tomba7N1.

A lot of different possibilities.. and there are even more. Just the best should be selected, or make some combination of presented. :friday

Tomba700 on 4.8 m, 19 bar, Sten 130.
[ame="http://www.youtube.com/watch?v=wqHX6weVJ-U&feature=player_embedded"]Prova Mares Sten 130 kit TOMBA psi 19 ATM asta devoto 7mm l. 135 cm - YouTube[/ame]
 
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foxfish said:
Great shot on a moving target!
Click to expand...

Yes foxfish! Even the hunter was surprised although he was not a beginner. And gun only on 19 bar! Target was from dense polyurethane 10 x 30 cm.

Here is an another idea for Tomba:

 
Almost all ideas on one picture. In green box are my favorite. All are working fine. Some from upper part of picture would work, others would not work reliable.



T1- will work fine, until scratches on the body of slider. Not robust, not reliable.
T4 - will be fine, but impractical to inspect or change O-ring inside steel ring.
T5 - Will be fine but additional tool for inserting O-ring might be necessary
T6 - complicated to use. Screwing/unswerving is necessary.
T7 - will work only in shallow water
T2, T3 - unreliable. Damage to O-ring possible.
 
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Hello tromic!
I read a lot about your Tomba system. My problem is a used Mamba kit on a Cyrano speargun. I have lost a plastic part from it and now i am searching for a better solution.
Is there any possibility to get a Tomba system from you, or a technical drawing/plan how to build it exactly?
Thanks! Greetings to Croatia!
 
Kinexium said:
Hello tromic!
I read a lot about your Tomba system. My problem is a used Mamba kit on a Cyrano speargun. I have lost a plastic part from it and now i am searching for a better solution.
Is there any possibility to get a Tomba system from you, or a technical drawing/plan how to build it exactly?
Thanks! Greetings to Croatia!
Click to expand...

Here is an earlier TombaF7 for Mamba for free shaft:
http://forums.deeperblue.com/pneuma...mba-all-one-barrel-sealing-18.html#post829217
You could make it without stainless steel bushing with ID 7,1 mm (7 mm shaft) and ID for O-ring (12 x 7 x 2,5 mm) 11,5 mm, without 4 deg cone. It would be fine. You could write to marko.romich@gmail.com and ask him for some details or other possibilities.
Cheers, Tomislav
 
Crimping the 1 mm mono to the slider (Tomba650) is maybe another possibility - less mess with knots and interconnections, and I suppose more hydrodynamic.

 
For choosing a right Tomba (Tomba700, Tomba715...) it is very important to know the exact shaft diameter. It is not same if the shaft is 7.0 mm or 7.15 mm.
Here is a trick how can one easily take a measure of a shaft diameter without a caliper. I suppose it is clear from the picture how to make a tool and how to use it.

 
This is an interesting measuring gauge, however plastic calipers can be purchased very cheaply, maybe only a few dollars. They are usually inaccurate in terms of the zero setting, so if you measure a known diameter and note a correction factor you can then apply this to other measurements. The jaws are not hard and will wear, but with relatively little use they are OK. Of course a good metal vernier caliper or digital caliper can be purchased for about $20 from places like Aldi. Engineering quality calipers are much more expensive, but you do not need them for most spearfishing related jobs.
 
popgun pete said:
This is an interesting measuring gauge, however plastic calipers can be purchased very cheaply, maybe only a few dollars. They are usually inaccurate in terms of the zero setting, so if you measure a known diameter and note a correction factor you can then apply this to other measurements. The jaws are not hard and will wear, but with relatively little use they are OK. Of course a good metal vernier caliper or digital caliper can be purchased for about $20 from places like Aldi. Engineering quality calipers are much more expensive, but you do not need them for most spearfishing related jobs.
Click to expand...

Thanks Pete! This information, you gave, will be useful for everybody.
My tool is actually not for measurement. Is is just for take a measure of a shaft diameter or to compare one shaft to another. You do not need to know the exact value. You can for example take a measure of a shaft you have and than send somebody your "tool" in a letter, to by you a shaft of the same diameter.
 
[ame=http://www.youtube.com/watch?v=Iw3M39bFQlw]How to tie knot on plastic slider - version 2 - YouTube[/ame]
 
Hi,
Does anybody know where I can buy Devoto or Seatec shafts for my Pneumatic? I live in the uk.
Thanks
North1
 
foxfish said:
You can use a different make of spear, they are pretty universal.
Click to expand...

Hi Foxfish,
Any suggestions for alternative shafts? I need to know what size I am going to use i.e 6.5 or 7mm before I get the kit made.
Currently I use 8 mm stainless Cressi on a SL70.
Not sure if the Mares 7mm would be suitable. Is there a difference in the base of the spear that pushes down the barrel?
Thanks
North1
 
Mares and Cressi shafts for pneumatic are not same. You might use a butt from Cressi and put it to Mares shaft. You can unscrew it from the shaft end.
 
Well it depends on what sort of kit you are going for?
If you want a free shaft kit (my favourite) then the spear end doesn't make any differance because it is removed!
I would go for a 6.5mm spear in your 70cm gun, just make sure it is a stainless one.
 
foxfish said:
Well it depends on what sort of kit you are going for?
If you want a free shaft kit (my favourite) then the spear end doesn't make any differance because it is removed!
I would go for a 6.5mm spear in your 70cm gun, just make sure it is a stainless one.
Click to expand...

Foxfish, it makes difference! the cones on the shaft tail are different. Mares cone will not match the cressi piston. Will not get in. Cressi cone will be lose in Mares piston. :friday
 
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