Tomba - All in One barrel sealing

[devondave]

That looks a serious bit of kit Dave , didn't someone ( Pete ? ) , post a picture of a Russian gun built on those lines ? I wonder why it was never developed further ?

Pete and Tomislav , it wasn't my intension to sidetrack your thread with that silly post , my apologies .

Tomislav , I've read the mod's you're trying on your Cyrano and was wondering if there's anything in particular you'd recommend ?
I made a few basic ones , bigger portholes , easier trigger , polishing various bits and pieces etc .
Considering the vis' I fish in is about 3m or 5m on a good day , is it worth doing any of the more complicated alterations ?

Regards ,
Dave .

 

[tromic]

...
Tomislav , I've read the mod's you're trying on your Cyrano and was wondering if there's anything in particular you'd recommend ?
...
Considering the vis' I fish in is about 3m or 5m on a good day , is it worth doing any of the more complicated alterations ?

Regards ,
Dave .

Dave, maybe you could try that Cyrano vacuum modification at the last picture. Just one O ring (7 x 12) mm at the shaft and rubber tubing over muzzle ports. Is it complicated? You will have 25 % more powerful gun. Than you could use some kind of more slim - hydrodynamic line slider, thiner line - monofilament, about 1.5 mm, and better harpoon and you will have about 50 % more powerful gun. At 10 m depth you would have even 60 % more powerful gun. Or you could leave it same powerful as before but with less bars in it, instead 30 bars just 20 bars and you will have the same result. Is it worth doing any of the more complicated alterations?

Regards, Tomislav

 

[devondave]

Thanks tromic , think I could just about manage those .
Can't give you any rep' , have to spread it around first .

Regards ,
Dave .

 

[foxfish]

Dave, you cant turn you head away from a 50% power increase! Let us know how you get on...

 

[tromic]

Thanks tromic , think I could just about manage those .
Can't give you any rep' , have to spread it around first .

Regards ,
Dave .

Do not forget to seal the muzzle threads with some silicone, not too much.

Regards, Tomislav

 

[popgun pete]

You could also remove the power regulator bulkhead from the "Cyrano", it is not hard to do, but requires patience, some intelligence and good manual dexterity. A diagram is attached showing the inner works of the "Cyrano". If you do not like taking things apart then forget about taking a "Cyrano" apart! That long snout meant more parts than usual as you can see by the diagram, parts 23 et al are unique to the "Cyrano". Most pneumatic spearguns just have a simple nose cone held on by the muzzle.

 

[tromic]

This tomba was one of the first. Too much drag, too much parts.

This one should be much better. Easier to use, much less drag.

The drawback is that this type requires different (new) muzzle or adapter to muzzle.

1-Adapter to muzzle ID 11.4 mm (like Cyrano has)
2-Metal stop ring: ID 7.1 mm, OD 11.2 mm
3-Plastic or rubber tubing: OD 11 mm, ID 7 mm or less to have sufficient friction to the shaft
4-O-ring 7x12mm
5-Slider made in plastic/stainless steel with annular groove for binding the line so to be more hydrodynamic.

After shooting there is no muzzle to shaft friction. O-ring would be knocked out from the muzzle by the (3).
Metal ring (2) prevents water inrush after shooting, keep the shaft centralized and prevents slider and other parts to slide down of the shaft.

 

[foxfish]

Tromic, what do you think about attaching the line to the front of the spear?
I used this mod & have found no disadvantages only a much simpler loading operation.

 

[tromic]

Tromic, what do you think about attaching the line to the front of the spear?
I used this mod & have found no disadvantages only a much simpler loading operation.

foxfish, I am not sure about that. Here is what I answered to Old Man Dave: "The result of test was very bad. It seems that the drag of the piece of spectra attached to the head was very high. Although this was vacuum barreled gun it was outperformed with wet barrel gun by 110 %. I could not explain how it is possible. Is it possible that the 1.6 mm spectra cause such a high drag or the cause is the loop slider made from spectra at the back and of the shaft (look at the picture)? The same gun, with same, arrow but without the spectra attached to the head of the shaft was 48% better than the factory gun - wet barrel". I will repeat the measurement once again, on summer, maybe with some variations.

 

[foxfish]

I have no evidence to say your are not right but it just seemed to me that my spear flew straighter & faster?
Anyhow i was very surprised with my guns performance as I just could not see how it was going to work very well but as several other guys on this site & other sites convinced me to give it a go.
One thing is for sure, the loading is very simple!
I hope you can get to do some more test soon

 

[tromic]

I have no evidence to say your are not right but it just seemed to me that my spear flew straighter & faster?
Anyhow i was very surprised with my guns performance as I just could not see how it was going to work very well but as several other guys on this site & other sites convinced me to give it a go.
One thing is for sure, the loading is very simple!
I hope you can get to do some more test soon

Before I did the measurement I thought as you. It seemed to me that my spear was 2 x faster. I could not believe! I am speaking about this configuration at the picture. You could not see the front end of the shaft. The spectra was tied to the head of the shaft to be most hydrodynamic. The only bad think is maybe what you see at the picture, the "loop slider". Maybe it would be better without that loop?



I did the measurements 3 times and the result was 11 cm at the scale (look at the picture). After that I measured using the "spring slider" and the result was 20 cm at the scale. To remind, the result with water barrel gun, which I took as reference, was 16 cm. From this scale one could calculate the ratio of energy of the shaft. For example, in this case:

factory water barrel / this vacuum barrel setup = (16^2) / (11^2) = 2.11 what means that in this case water barrel was 2.11 x better in energy, or 111 %.

Hard to believe but that is the fact.

 

[foxfish]

Very interesting!
I tried a few methods but decided on drilling the spear in the end.
I think there is scope to try different types of line - perhaps using 150lb braided fishing line for the length of the spear as this is very thin & flexable, then attaching to mono?

 

[tromic]

Did you find this tovarich to be better than mamba? I know it is easier to use. What is your experience with the new Airbalete 90? Have you got it?

 

[tromic]

foxfish, I tried this too:



You can see the thin, 0.4 mm fishing line tied to the 1.6 mm spectra.
The result was 20 at the scale, so the line which would be used is very important for performance. If we calculate we get: (20^2) / (11^2) = 3.3 x better performance then with spectra alongside the spear or 230 % better.

 

[tromic]

Very interesting!
I tried a few methods but decided on drilling the spear in the end.
I think there is scope to try different types of line - perhaps using 150lb braided fishing line for the length of the spear as this is very thin & flexable, then attaching to mono?

Foxfish, I would like to know which setup would be better:
1. like your, at the picture, which has some drag from the line attached to the head of the spear, or
2. like Airbalete has with microspeed slider where the slider causes the drag.

I am interested in drag, not the performance of the gun.
This would be easy to test. Two shoots from Airbalete: one with 1. and other with 2. Same gun, same spear. Just should be measured the difference.

 

[foxfish]

I dont own a airbalete the gun pictured is my own modified omer 90.
I really like the simplicity of loading without the slider regardless of performance.
I am most interested in spear speed as I dont really need the long range, I have tried various spear lengths & diameters but now use a 1000 x 6.5mm set up.

 

[tromic]

I dont own a airbalete the gun pictured is my own modified omer 90.
I really like the simplicity of loading without the slider regardless of performance.
I am most interested in spear speed as I dont really need the long range, I have tried various spear lengths & diameters but now use a 1000 x 6.5mm set up.

Somebody told that he was waiting for his new Airbalete. I thought it was you. So am I interested in spear speed. I use the same spear as you, with my Cyrano 850, 6.5mm x 1000, demka vector, tahitian.
Regards, Tomislav

 

[foxfish]

How about a basic ballistic test like firring into a block of uniform material, polystyrene maybe?
Surely this would give a very good indication of power & penetration & would be the easiest of all test?

 

[tromic]

How about a basic ballistic test like firring into a block of uniform material, polystyrene maybe?
Surely this would give a very good indication of power & penetration & would be the easiest of all test?

Why not! Although, to me, my test seems to be easier to set up and maybe more practical. You could just submerge the gun and fire. Then read the result and prepare for the next fire. Because you have a fixed length line you should not take care about distance to the target. The results I got were closely grouped together for different cases (mamba, tomba,...). I am sure it would be easy to observe even tiny differences. I would do the test again but I am far away from the water where I could make tests. I should wait for a summer holiday. If You could do some tests I would be glad to see your results.
Regards, Tomislav

 

[foxfish]

The only power test I have ever completed were not done in a recommended way or particularly accurate - please dont do this at home chaps!
http://forums.deeperblue.com/pneumatic-spearguns/66155-air-guns-2.html