Own Mamba design

[radlimus]

I build for my cyrano spergun my own mamba design.
It is a little bit different to the other systems.
I made this evening the first test an the reach is about 25% better:friday.
More details and maybe a few pictures will follow the next days.

 

[Don Paul]

Sehr gut,radlimus:friday
Cheers, Don Paul

 

[foxfish]

Yes please photos if possible..

 

[tromic]

I build for my cyrano spergun my own mamba design.
It is a little bit different to the other systems.
I made this evening the first test an the reach is about 25% better:friday.
More details and maybe a few pictures will follow the next days.

How did you measure 25 % better reach?

 

[radlimus]

First i have to say thank you to tromic.
He try to explaine me how the conventional mamba sytems are working.
But i didn`t uderstand it, i am not sure if the systems are really proof against incoming water, friction and negative pressure in the barrel.

So i made my own thoughts.
I sealed the top of the cyrano speargun with 2 O-rings and a relocatable sleeve.

So i can decide if i want to have acess from air or water to the barrel.
Closed system:

The new thing is the simple seaking of the spear.
I put a O-ring on the spear and build a sealing Delrin bush.

The bush is fixed by 4 little niro screws.

The spear was modified, single diameter, necessary for the Mamba system.

 

[radlimus]

Testing:
I have to test my speargun in a swimming pool:waterwork,
the sea is too far away......

I put a wine cork in front of the spear and made 2 shoots in the pool (the pool was empty of course, no people there).
There were no line between the gun and the spear.
First shoot without the mamba and the second shoot with mamba but both shots with the modified spear.
Reach 1 shoot: 4.2 meter
Reach 2 shoot: 5.2 meter

The next thursday i will made a shot with the unmodified spear, the reach will be less than the 4.2 meter.

 

[tromic]

First i have to say thank you to tromic.
He try to explaine me how the conventional mamba sytems are working.
But i didn`t uderstand it, i am not sure if the systems are really proof against incoming water, friction and negative pressure in the barrel.
...
So i can decide if i want to have acess from air or water to the barrel.
So i made my own thoughts.
I sealed the top of the cyrano speargun with 2 O-rings and a relocatable sleeve.
Closed system:
...
The new thing is the simple sealing of the spear.
I put a O-ring on the spear and build a sealing Delrin bush.

The bush is fixed by 4 little niro screws.

The spear was modified, single diameter, necessary for the Mamba system.

This time I am who don't understand you. Are you trying to say your system is tovarich like - spear without butt and slider: "The spear was modified, single diameter"? What is the ID of Delrin bush? Is there groove for O-ring inside the Delrin bush?
Sealing the top of the cyrano speargun with 2 O-rings and a relocatable sleeve was an option at the very beginning of my design of tomba but I think it is better with rubber tubing. Nice to see some new approaches.
Regards, Tomislav

 

[radlimus]

Inside the bush are 2 diameters, the smaller one is a little bit bigger than the diameter of the spear.
The bigger one ist depending on the o-ring of the spear.
The material of the spear is very hard and it is difficult to work with it. It is better to build first the groove of the spear and then build the right bush.
The spear is without a butt and without slider.

 

[radlimus]

This evening i was again in the swimming pool and make a shoot with the speargun.
This shoot was without any modifikation.
The reach of the spear was 3.55 meter.

If we have a look at the different perfomances;
Modified 5.20m
Unmodified 3.55m
then we see that the gun got much more power with the modifications.
The next test will be with a pressure of 25 Bars.

 

[tromic]

Inside the bush are 2 diameters, the smaller one is a little bit bigger than the diameter of the spear.
The bigger one ist depending on the o-ring of the spear.
The material of the spear is very hard and it is difficult to work with it. It is better to build first the groove of the spear and then build the right bush.
The spear is without a butt and without slider.

Thanks. Is is possible to put a picture of the spear? Why do you need the groove on the spear? I steel believe your design is like tovarich system. O ring is inside the bush, all the time. Right?

 

[popgun pete]

Hi radlimus, if you decrease your photo file size then you will still get your images across, they do not need to be so large. Thanks for posting them.

 

[radlimus]

Thanks. Is is possible to put a picture of the spear? Why do you need the groove on the spear? I steel believe your design is like tovarich system. O ring is inside the bush, all the time. Right?

I will post new pictures here and i try to make them smaller.

The O ring is part of the spear!
Thats more complicatet to build but it is much better for the reduced friction.

The great advantage of my design is the high power, the other side is the more complicated handling because you have to empty the water out of the gun after loading the gun, it takes about 5 seconds.

 

[foxfish]

This sounds very interesting please try to put on some resize photos so we can understand how you system works.

 

[Old Man Dave]

I've edited the picture size. Still a bit big, but at least you can see the detail now.

Dave

 

[popgun pete]

It appears that this is a dry barrel system, not a vacuum barrel system. You load the gun, the barrel already has water inside it, the spear seal at the front end plugs the end of the muzzle and then you lift the gun clear of the water and allow the water to drain from the inner barrel through the muzzle relief ports which are open. After that you slide the muzzle cover shut to close the muzzle relief ports which keeps the water from going back into the inner barrel. There is probably a bit of water still left inside, but nothing to worry about, in fact you need a small amount of water for lubrication.

 

[foxfish]

Is there any benefit over a vacuum system?

 

[popgun pete]

The gun will blow a few bubbles after the shot as it ejects the air from the inner barrel, but should be a similar performance to a vacuum barrel type. You have to use a front tied shooting line as there is no stop diameter on the spear tail for a line slide, which is what the "Mamba" type system allows you to retain.

 

[Old Man Dave]

I wonder how easily the water drains from the loaded gun? Shaking a loaded gun pointing downwards above your head while treading water doesn't seem easy - or safe. Or am I not understanding this correctly?

Dave.

 

[popgun pete]

I guess it depends on how long the gun barrel is, a short pneumatic is relatively easy to pour the water out of while you are in the water. I will post a "dry barrel" speargun thread that I had prepared earlier as a new topic.

 

[tromic]

Radlimus, although I haven't seen the shaft with the sealing O-ring yet, I would say your dry barrel system is OK. It is next to vacuum barrel tovarich system regarding performance. There is no vacuum inside the barrel but there is also no friction between the shaft and the sealing O-ring.

At the moment I see only 3 drawbacks:
-the shaft is weakened at the groove position of the sealing O-ring,
-creates air bubbles after the shoot - not a big problem,
-takes some time to empty the water and close the muzzle holes - not a big problem.

Regards, tromic