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popgun pete 12-01-2016 11:51 PM

Re: Alemanni Demultiplied Rollerguns
 
1 Attachment(s)
Quote:

Originally Posted by Behslayer (Post 2125495)
Ha, you're hilarious, Il Maestro is how some of us gun builders refer to the Italian master gun builder Itio Alemanni.

My friend Peter Correale brought one by the shop a few weeks ago. The guns are very different than I had thought only seeing the pics. My immediate thoughts were Wow. that is a Thin Blade. There's so much going on with these guns that you can't even see in the pics. Not only did the shaft not touch the track for most of the gun, there's actually quite some space between the shaft and the gun. The Teak is laminated up with CF cloth between the lams. The direct comparison was more to a Sword than a gun.

Well with nothing coming up when I searched "Il Maestro" I thought you might have been referring to the web-site directly under your forum name. Couldn't see a rollergun, so I commented on those guns instead. The Tuna in the various photos show that they don't need a rollergun to knock them over. This is the paint job I was referring to. Here you pull four bands back and bar band soak losses, you get four bands' worth going out when the spear heads to the target while the gun pushes back, hopefully with ballast to ameliorate the effect.

popgun pete 12-02-2016 12:22 AM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by Satdiver (Post 2125541)
Hi Behslayer, yes there is a lot going on with these guns. There is a lot of thought and testing that has gone into this gun design. The first thing when you shoot this gun, is the very little recoil, there is almost no kick at all. I use 3 raps of shooting line on this gun.

I would say this style of gun is not for everyone. You need to use a hook from your wrist to grab the dyneema from the front to load to the first rest tab. There is lots of bands to tie.
But if you are after a very powerful bluewater gun that is extremely accurate to 7mts with almost no kick you should give one a try.

Hi Popgun Pete, I got my friend that is using my gun at the moment to take some photos of the vela unloaded and loaded. The photo's are not so clear, but you can see how the gun looks loaded. I'm not sure what shark fin my friend has put the top dyneema line on, the pulley bar should be a little closer to the front roller in the photo of the bottom of the gun when loaded.

Thanks for all the photos, you can see how the bands all thin out at full stretch. Any idea how much stretch is on band group 2, the bands that run on the top and bottom decks via the rear pulleys in the side stock/body windows before anything is cocked? That band group 2 tension must keep the cables taut on the unloaded gun. You would not want to run the underside of the gun over any sharp objects, e.g. barnacles, coral or jagged rocks on a crevasse or reef channel with all that taut rubber running the full length on the underside.

Satdiver 12-02-2016 01:11 AM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by popgun pete (Post 2125547)
Thanks for all the photos, you can see how the bands all thin out at full stretch. Any idea how much stretch is on band group 2, the bands that run on the top and bottom decks via the rear pulleys in the side stock/body windows before anything is cocked? That band group 2 tension must keep the cables taut on the unloaded gun. You would not want to run the underside of the gun over any sharp objects, e.g. barnacles, coral or jagged rocks on a crevasse or reef channel with all that taut rubber running the full length on the underside.

-I cut and tie my new bands the same length as what the gun came with.
-You are correct- the 20mm bands that go through the back roller to the top stay on all the time, this keeps all the other bands together.
-I haven't damaged any bands while the gun has been loaded.

I will try to explain the loading technique-
1st- pull the 2 bands through the back roller to the tabs that are on top.
All the other bands are not connected at this stage.
2nd- you use a hook that's on your wrist, grab the dyneema line at the front and pull to the rest tab that's on your shaft. Then reach without the hook and pull back to the back tab.
Turn the gun over, Working from the center to outside.
3rd- grab the the band next to the band that goes through the back roller and load to the small round loading tab.
4th- pull the next band to the larger round tab, this has a grove for the line.
5th- pull the outside band to the large round tab. This band is one continuous loop band with only loops to the bar.

It sounds quite complicated, but once you have loaded it a few times it's quite easy and fast. You have to remember this gun is shooting a 170cm x 10mm shaft, so it need loads of rubber.
I'm only 5ft 8in and I have no trouble loading this gun. It's more technic.
The other thing I will say, this gun is very well balanced and very easy to dive with for such a large gun.

popgun pete 12-02-2016 02:48 AM

Re: Alemanni Demultiplied Rollerguns
 
When you install new bands do you check out the old ones to see if they have developed any flaws? I guess it will depend on how long there is between the changeovers. In some climates, or rather polluted environments, bands can turn their toes up before they lose their zip, plus being cooked in a closed up car does not do them any good either. Once I used to keep made-up spares on hand, but on stretching them to check them out they were often found to be no good despite them never having seen any service, even though they had been stored in zip lock bags.

Satdiver 12-02-2016 03:19 AM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by popgun pete (Post 2125552)
When you install new bands do you check out the old ones to see if they have developed any flaws? I guess it will depend on how long there is between the changeovers. In some climates, or rather polluted environments, bands can turn their toes up before they lose their zip, plus being cooked in a closed up car does not do them any good either. Once I used to keep made-up spares on hand, but on stretching them to check them out they were often found to be no good despite them never having seen any service, even though they had been stored in zip lock bags.

I probably change my bands before it's really needed. Well before any flaws developed in the bands. I know Mr Alemanni cuts and tyes the bands at a low percentage, so the bands do last a long time on the Vela. To be honest, I don't mind tying bands.
I always have made up a complete set of bands. I keep them in a zip lock bag in the fridge when I'm not in Bali. But you are probably correct about having bands made up to long before use, they probably do deteriorate.

Behslayer 12-02-2016 12:31 PM

Re: Alemanni Demultiplied Rollerguns
 
SATdiver have we met?

Honestly, that blue 3 band rear handle in the photo has very little recoil and is deadly accurate with power past 7mtrs.

Pete, that's funny. Ulusub is just some of my own whittlings. Yes. it is possible to capture Tuna without Sheaves. What interests me most about Rollers is the Recoil Cancel. But, that being said, those things better be shooting pretty damn special to justify all that stuff.

jstiver09 12-02-2016 12:57 PM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by behslayer (Post 2125619)
but, that being said, those things better be shooting pretty damn special to justify all that stuff.

exactly

Behslayer 12-02-2016 10:27 PM

Re: Alemanni Demultiplied Rollerguns
 
3 Attachment(s)
I had one of these in my hands the other day. I do get nervous looking at things with too many bands and strings going in different directions. But this is the Alemanni Doppia system inline double roller and although it does require a loading hook, other than that it's just a simple double band Speargun.. that shoots an 8.5mm Shaft 20'+ without recoil.. I never got a chance to fire this thing, so I am taking that on faith from my friend Don Pedro. I had this gun in the shop for a few days and I looked at it a lot. I'm pretty good with looking at a wooden speargun and figuring out how it was made, but I literally had to measure this thing to understand some of the subtleties. Holding the gun from the handle there is a cantilever experience as the whole body of the gun is lower than the handle until the muzzle. And the muzzle seems to be on a different angle from the rest of the gun. I couldn't really figure out what was going on but the whole experience was pleasant. I did whip out my chisels and whittled away at a stick.

popgun pete 12-03-2016 02:47 AM

Re: Alemanni Demultiplied Rollerguns
 
Found a price for the "Vela 135 Special": https://www.freedivershop.com/aleman...oller-speargun

Looks like another trip in the Lambo SUV is required to buy one of these expensive looking cable rollerguns, with the retail price dollar figure to match!

popgun pete 12-03-2016 04:57 AM

Re: Alemanni Demultiplied Rollerguns
 
1 Attachment(s)
Quote:

Originally Posted by Behslayer (Post 2125666)
I had one of these in my hands the other day. I do get nervous looking at things with too many bands and strings going in different directions.

Rollergun performance incentive program.

TVA 12-03-2016 06:22 AM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by Behslayer (Post 2125666)
I had one of these in my hands the other day. I do get nervous looking at things with too many bands and strings going in different directions. But this is the Alemanni Doppia system inline double roller and although it does require a loading hook, other than that it's just a simple double band Speargun.. that shoots an 8.5mm Shaft 20'+ without recoil.. I never got a chance to fire this thing, so I am taking that on faith from my friend Don Pedro. I had this gun in the shop for a few days and I looked at it a lot. I'm pretty good with looking at a wooden speargun and figuring out how it was made, but I literally had to measure this thing to understand some of the subtleties. Holding the gun from the handle there is a cantilever experience as the whole body of the gun is lower than the handle until the muzzle. And the muzzle seems to be on a different angle from the rest of the gun. I couldn't really figure out what was going on but the whole experience was pleasant. I did whip out my chisels and whittled away at a stick.

Very interested to see some performance tests with that double roller you're working on Jon. I'm dreaming up a similar prototype with Hatch

gspearguns 12-03-2016 11:18 AM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by Behslayer (Post 2125666)
I had one of these in my hands the other day. I do get nervous looking at things with too many bands and strings going in different directions. But this is the Alemanni Doppia system inline double roller and although it does require a loading hook, other than that it's just a simple double band Speargun.. that shoots an 8.5mm Shaft 20'+ without recoil.. I never got a chance to fire this thing, so I am taking that on faith from my friend Don Pedro. I had this gun in the shop for a few days and I looked at it a lot. I'm pretty good with looking at a wooden speargun and figuring out how it was made, but I literally had to measure this thing to understand some of the subtleties. Holding the gun from the handle there is a cantilever experience as the whole body of the gun is lower than the handle until the muzzle. And the muzzle seems to be on a different angle from the rest of the gun. I couldn't really figure out what was going on but the whole experience was pleasant. I did whip out my chisels and whittled away at a stick.

:)

This is a classic double roller. I can imagine how would have been confused if you had invert roller in your hands.

That gun has no track except little piece in front of trigger mechanism and open tube muzzle which really is set up to raise front end of shaft.

popgun pete 12-03-2016 05:26 PM

Re: Alemanni Demultiplied Rollerguns
 
3 Attachment(s)
Here is a non-demultiplied Alemanni rollergun, the "Stillo Express Double Roller".

Note the length of the bands, which when cocked run on both the top and bottom decks of the gun, and that this is not a cable gun. The bands have a certain degree of pre-loading as they are taut on the bottom of the gun with the cord wishbones at the muzzle.

The use of a "pulley" as a rear band anchor allows the band lengths to equalize on either side of the gun. Georges Beuchat had the patent on this pulley idea for a forward band anchor, but to my knowledge it was never used on a production speargun as a loop band works OK on a slotted end muzzle without resorting to a pulley.

If there is any "booster" on the demultiplied, cable rollerguns then it is in the tension applied during band set-up to band group 2. That is what differentiates them from the other Alemanni rollerguns and that is why they need to wrap over both decks of the gun even before cocking the guns in order to not stretch the guts out of those bands.

Satdiver 12-03-2016 08:00 PM

Re: Alemanni Demultiplied Rollerguns
 
There maybe a little confusion with the difference types of roller guns designs.

The roller gun with the pulley system is called- Inverted roller, this design has the least amount of recoil in the roller gun designs. Although these guns come with a booster band, you don't need to use it. And when you don't, it reduces the recoil almost to nothing.

The classical roller gun has the bands going through the front rollers back along the shaft to the shark fin. There is a few variations of these design. If you look on Alemanni website you can see.

This is a video on YouTube of shooting in the pool with 135 Vela, Target is set at 8mts. I don't know how to attach the link, but google this- testing Alemanni vela135 special blue water super speargun
https://youtu.be/OX2cNb-bm0A

Hi Behslayer, no we haven't meet, But you are very well know in Bali Jon. The gun you talk about Jon, I have used the same design gun in the pool. This gun shoots very fast and is very accurate to 6mts with almost zero recoil. Alemanni also has a 115 carbon fibre roller gun thats the same design that shoots a 9mm shaft, this gun is what Mr Alemanni uses on his Mexico trips. I have also tried this gun as well, its very impressive.

I will say this, If you are going to use these style of guns as a reef gun, You cannot reduce the power of a roller gun or to shoot under a rock. If you shoot under a rock with one of these guns you will defiantly get your shaft stuck or bend the shaft.

Diving Gecko 12-03-2016 10:44 PM

Re: Alemanni Demultiplied Rollerguns
 
Quote:

Originally Posted by Satdiver (Post 2125737)
There maybe a little confusion with the difference types of roller guns designs.

The roller gun with the pulley system is called- Inverted roller, this design has the least amount of recoil in the roller gun designs. Although these guns come with a booster band, you don't need to use it. And when you don't, it reduces the recoil almost to nothing.
[...]

I think it is even more complicated than that and that some of the designations are used interchangeably now.
If I am not mistaken, an inverted roller original means that the band's back end is tied on top of the gun. Often recessed in a groove in the stock. From that anchor point, the band goes backwards through a roller near the handle, up towards the muzzle on the under side of the stock and then dyneema is tied to the band which then goes through the smaller rollers in the front and forms a very long wishbone, so to speak. In terms of force, we are still talking one straight pull from the rubbers as in 1:1. But an inverted roller has even less recoil then a normal roller because very little of the rubber moves forward during the shot and it has a cleaner sight line on account of the dyneema.

It seems 'inverted roller' is now somewhat interchangeably used for what was originally called a pulley/compound/polispast or demultiplied gun where pulleys are incorporated to change the band force so that it is not a straight 1:1 as Pete explains in the first post. Even some manufacturers call their demultiplied guns for inverted rollers.

And then of course there are combinations of the two above.. E.g the Alemmeni that started this thread is a demultiplied rollergun with an inverted band, too:scratch::cool:
At least this is if I "read" the Alemanni pics correctly and if my internet gained knowledge is not flawed:-)

I think Pete has some nice diagrams illustrating the difference, perhaps he can share them again:-)


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