Barrel Flex !!

[Memo]

Hi,
Upto my last dive trip I didnt truly believe in alluminum barrel flex in long aluminum guns and I think it was a theoretical issue...

My current gun is 110cm long with aluminum barrel loaded with 20mm single G20 cressi rubber.

Here are the pictures that I discovered

 

[Memo]

the mid section barrel flexing is obvious as you can see.:naughty

 

[Memo]

luckily Aydin, gave me a hand, and his friend will manufacture me a new aspetto gun

 

[aydin]

Very good work Memo,congragulations.
A friend of mine,who makes wooden spearguns made and show the approximately whole well known brands either alluminum,carbon or another except the laminated wood bend and flex obviously.
Thank you for this demo,everyone must do this test to their own guns at home,and think twice..
Its a mechanical issue but this flexion absorbs too much energy and stability i think....Nice to see you going to the wood..

 

[Memo]

I believe in the stability problems too. Although the accuracy is perfect at close ranges, long shots always cause some problems.

 

[Iyadiver]

Very interesting Memo, nice info. Thank you.

Rubber being on top of the barrel does seems to flex out the barrel. If the load of the rubber can be placed in the middle of the tube barrel, perhaps it will be different.

 

[Memo]

Maybe.... The moment that the rubbers apply on the muzzle seems to make the job A lower muzzle or a rubber allignment that you specified will make things different for sure...

 

[Murat]

Hey memo,

You will buy gun from Levent Gozen? Whých model and how much?

I saw some of his gun's pic in local omer site which looks similar to the pelagos. But if there is not much price difference, pelagos may be a better choice.

 

[Dogmatrix]

it would have been nice to see some pics from the same angles of the same gun when unloaded.

Rob

 

[fuzz]

True, always need a "control group" picture for comparison sake.

Nice pics though Memo, I think I'll go home & load a couple of my alum. guns to test. I generally underpower mine, so I don't think it'll be too much of an issue... I hope.

 

[Dogmatrix]

I generally give my 1.4 RA Saracen a bit of a workout... double 16mm rubbers cut short... If you want to see some similar pics with this loaded up I can do that

Don't think their will be much difference from the control

Rob

 

[shaneshac]

Hey Memo,

Is that hole in the pinboard a practice shot you took indoors?

WHat length G20 bands have you got on your 110?

 

[aydin]

the position of the rubber whether on the top or midsection of the rubber(like the sling) does not change anything Iya,if it is not laminated wood or very thicker carbon ,all standart carbons or aluminium,etc always shows this flexion to a degree depends on the barrel length and rubber length and thickness..

 

[aydin]

Hello Murat ,
The web site that you have seen Levent's guns have no relation with Omer brand ,like a joke the name of the guy is Ömer,it's real..
And this guy have put the Levents guns to his site without any permission of Levent,and after a little!!!! warning they take away these photo.. Bad story..
Aydýn

 

[Murat]

Yes Aydýn, i know that. Thats why i said "his gun's" in previous post.

Anyway, Do you know that gun's price by the chance?

 

[aydin]

I can learn the price tomorrow Murat

Aydýn

 

[Memo]

Well I can take few pictures tomorrow for some control purpose

Shane, my rubbers are 27.5cmlong, and you have to see the holes at the window

Murat, yes aydýn referred Levents guns and I think I will order one with the barrel desing similar to pelagos but with a plastic handle (possible excalibur or T20). The new gun will be 110cm as well.

 

[Memo]

I also think getting a 75cm alluminum barrel for my 110cm cressi and generate it into a perfect small gun

Murat I'm thinking of getting totem rubber to this gun as well.

 

[Memo]

okay here is the new set of pictures


the unloaded gun for all of you to compare the barrel when loaded.. (ignore the bended spearshaft as I put it on the books to take the picture.)

 

[Memo]

now the flexed barrels
note: I didnt put the tip of the spear anywhere so you can judge the load of bands easily...