Arbalete Pneumatico Santino

[popgun pete]

Maybe this is the muzzle port here, being used as a sort of muzzle compensator by directing a water jet upwards.

This feature does not appear on the earlier muzzle which would make sense if it was a vacuum barrel shooting bare tail spears.

 

[popgun pete]

More views of the gun showing how the trigger mechanism fits into the stock, it being integral with the barrel and tank as a sub structure, and what I assume is a frictionally loaded side-mounted line release.

The line release pivot is related to the black item forward of the reel axle and may be a rubber friction block.

 

[popgun pete]

I suppose so too. There are neither water escape ports as usual. Water must escape forward with the spear...
Next I suppose that the compression ratio is probably CR > 2.5
I made an estimation using my speed-energy calculator. For the longest model speargun, 120 cm a suppsed the working couse of the piston to be 115 cm (maybe it is less, 110 cm?). On 11.76 bar (12 at) with CR=2.5 if the spear weight had been 361 g the initial speed of the spear would be about 34 m/s.
Initial loading effort 12 kgf and final loading effort about 29 kgf. I did not take in calculation water column around the shaft so the result might be a bit worse.. (The Force on the spear on shot is the average force)

View attachment 54257

The final pressure for the later version seems to be 25 bar and as initial charge pressure is a maximum of 12 bar then the compression ratio must be 2.0. That means the gun shoots much like a dual power pneumatic gun set to low power as for a compression ratio of 2.0 that means Vb equals Vr. Vb is the volume of the barrel and Vr is the volume of the reservoir and/or any other sections behind the piston when the gun is cocked to shoot. In dual power guns low power can be much lower with a compression ration of 5, so the Santino gun shoots a bit better than that with a compression ratio of around 2.

Probably comparable to the monotube guns such as the old Nemrod "Torpedero" (or Russian "green stick" copy) in terms of compression ratio, but this gun will have modern seals and a way better trigger mechanism with a rear tied spear.

CR = initial volume divided by final volume or (Vb + Vr)/Vr = Vb/Vr + 1

 

[tromic]

I don't believe that the average pressure of 18.5 bar = (25 + 12)/2 would be sufficient for 11 mm piston..?
It would be like Cyrano on 18,5 bar while normal operating pressure would be near 30 bar.
I agree about the muzzle port...

 

[popgun pete]

Watch the videos of the gun shooting and the gun being pressurized where we see the needle on the pressure gauge moving, it moves to just under 12 bar.

The "Arbalete Pneumatico" seems to be designed for general purpose spearfishing rather than high power shooting.

 

[tromic]

Yes it is possible for the 120 cm model the shooting range to be 5,5 m having average pressure of 18.5 bar because the working length of the piston is long - maybe 110 cm (?) and I also notice that probably 1 mm mono were used with his setup.. In that case the initial speed of the spear would be about 31 m/s and shooting on 5,5 m is possible.

 

[Vlanik]

Вланик-60 обладает такими же характеристиками.

 

[popgun pete]

Out of curiosity just decided to look in on the Arbalete Pneumatico Santino and found something that had a run in with one of the guns! Meals are assured for a couple of days.

 

[popgun pete]

The line release is a passive type where the release friction can be adjusted by loosening or tightening a nut that compresses the rubber bush that the inner end of the line release arm has to push past when the shooting line pulls on the outer end of the arm. When the rubber bush is being compressed it spreads in diameter and increases the resistance to the line release moving and the opposite occurs when you unscrew the nut. This is the view that you see after the reel and its base plate are removed followed by the trigger finger guard and its forward housing which are both held in place by the four vertical bolts with washers and lock nuts holding all these sub-assemblies together. As you can see one bolt acts as the line release arm pivot pin.

 

[Diving Gecko]

I watched some of the videos, too.
I think the trigger is quite "forward' so a lot of loss of piston travel length. Also, the muzzle inserts quite deep into the barrel. There's some black sleeve on the front of the piston and it sounds like he says "Delrin" when he points to it in the video and it looks permanently attached to the piston making it a very, very long piston.
Also, since he already has that pivoting arm for the trigger, it should have been fairly easy to make it interact with an active line release. On a front tied shaft, perhaps you can get by with a passive release as the shaft is still fully supported when it has to pull on the release but on a slider shaft, I would not want my shaft to have to jerk free a passive release at a point when the shaft has left the barrel.
Combined with the less than ideal compression ratio you guys have already mentioned I feel like there's some missed areas of potential performance improvements.
Besides that, I like the basic idea of the high barrel and moving the reservoir elsewhere on the gun

 

[popgun pete]

Limited production hand-made gun, so he has kept the design simple to work on. The piston looks like a modified later "Cyrano" piston with a rubber shock absorber on the piston nose. If shipping from Italy was not so expensive then I would buy one.

 

[popgun pete]

If you want to buy one then this is the order form that you need to fill out, translated from the original in Italian. I suggest you use the original (pdf file), but here you will know what to fill out.

Arbalete Pneumatico

Directives on the sale and use of compressed air fishing rifle

(COMPILE IN CAPITAL LETTERS)

I SUBSCRIBE......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Born in............................................................................................................................................................................................. PROV.............................Il........................... Tel.........................................

Cf. ........................................................................... and resident at ........................................................................................ .................

Zip.............................. I want the product to be shipped to the following address:

".................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

N................. Zip.........................

-For the coloring of the barrel (gun body) I want the color: ........................................................................ (indicate the ones in the catalog).

-For the construction of the fishing rifle, I want it to be cm long............................

-For the side of the undocking (line release arm) I want it to be positioned at................................. (indicate the right or left side).

-For the construction of the handle I want it to be:............................................................. (indicate: Left/Right).

In addition, I declare:

To be aware that you have purchased an underwater oil-and-so-called fishing rifle potentially dangerous.

To take all civil and criminal responsibility for the proper and improper use of the fishing rifle compressed air diver provided to me by this company.

In addition, I raise the company SANTINO OF FIRST from any responsibility and damage caused to people or things.

I declare that I am an expert in the use of air-based underwater fishing rifles and that I am technical and usage recommendations provided to me by the company.

I declare that I take any responsibility for tampering or modifications made on the rifle and the resulting loss of the guarantee established by the law on the artisanal products in question.

I declare that I take responsibility for jealously controlling and guarding the object in question and of make strictly personal use of it.

I declare that I am aware that I have purchased a handmade and small-scale aesthetic imperfections.

Date............................. Signature ………………………………….

 

[Diving Gecko]

Limited production hand-made gun, so he has kept the design simple to work on. The piston looks like a modified later "Cyrano" piston with a rubber shock absorber on the piston nose. If shipping from Italy was not so expensive then I would buy one.
View attachment 55841

Yes, that’s what I thought so, too. Especially as his screw-insertion tool grabs it nicely. But he talks about Delrin at that point but I guess that could be about something else.


Sent from my iPhone using Tapatalk

 

[popgun pete]

If the black extension was Delrin then the only reason for doing that would be to move the piston seal back from intruding into some port in the barrel tube when the piston hit the end of travel. There is a port in the top of the barrel, but it appears to be just behind where the screw in muzzle tip would end thus forming the anvil for the piston, so there should be no problem with the front piston seal hitting some discontinuity in the barrel. “Delrin” may have referred to the piston body, but I think that they are acetyl, or they seem to be that material in the first Cyrano pistons. There are other photos of the Santino pistons, but at high magnification the black parts don’t reveal more than you can see at normal size.

 

[popgun pete]

Some more photos of the gun's metal parts before being inserted into the timber outer stock.

 

[popgun pete]

Looks like this interesting gun has been updated. Here is the 2020 model.

http://www.arbaletepneumatico.com/