Spear tail to muzzle alignment pre the loading effort

[popgun pete]

We have seen that the vacuum muzzle production gun pioneer Taimen devoted a lot of effort into getting the shaft accurately placed in the muzzle before commencing the push onto the shaft into the gun. This consisted of a relatively long alignment by the line slide or slider which plugs into the muzzle and the centralizing bore of the shock absorber body. Pelengas did the same with their slider which sockets into the muzzle nose. What Salvimar should do is get rid of their current iine slide and make a more plug like version and take advantage of their slightly longer muzzle nose. The benefits of their current line slide's small diameter are illusory, they need something bigger than the slotted tail effort which busts and will not take a woven line as right now it is only set up for mono.

In this thread we looked at the new longer nose Salvimar muzzle https://forums.deeperblue.com/threads/salvimar-vuoto-muzzle.120815/, but we saw no cutaway of the internal view.

Here I show the proposed extended recesses for plugging in new sliders that confer a stronger alignment than that achieved now. LG Sub, which use a mini mamba system, also has a better alignment by similarly plugging the slider into their muzzles. Right now Salvimar is a job half done, they need a plug in slider that ensures alignment of the shaft tail, the stop ring is too short but could be augmented with a longer body on the plastic slider that then sockets in..

Note the above image has been altered by stretching the front end of the muzzle. Another approach would be to use a slider holder as seen on the front of the Taimen muzzle.

 

[popgun pete]

Just doing a search I see Salvimar has a new slider, but there is no mention of what guns it is used for on the Scubastore site.

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Looking a bit further down the page it is obviously a pneumatic.

The next question is does this new slider plug into their vacuum muzzle? It appears to be for mono judging by the tiny holes. My thoughts are the original Cyrano slider with its hydrodynamic shape would be a better starting point. This plastic slider was developed after testing by the University of Genoa based on my memory of it at the time of its introduction.

More here on the new sliders. https://forums.deeperblue.com/threa...pear-tails-and-sliders-or-line-slides.123006/

 

[popgun pete]

We can see the Pelengas slider plugging into their later Profi muzzle here. The early Magnum guns screwed the plastic nose end into a threaded cup to trap the rubber vacuum cuff, whereas this version screws over the muzzle end thread. They both have a close fitting bore to push the slider into.

 

[popgun pete]

Many of the vacuum barrel guns on offer are shooting 7 mm spears, but many including myself would rather have 8 mm if we are taking on more substantial prey. What is needed is size dedicated sliders, shock absorbers and vacuum cuffs. All purpose one size fits all are not much good with the bigger diameter shafts and tails, ideally you need an 8 mm vacuum cuff. When the Taimen originally appeared it came in 6.5, 7 and 8 mm versions and each had their own muzzle and vacuum fittings. In recent times they dropped the 6.5 mm version which in my view is no loss. To my knowledge Salvimar have only offered an all purpose vacuum cuff, but I think this needs to change, however I have not checked the situation in recent times.

Now I have and nothing has changed.

You can get away with fatter spear tails if polyurethane bushes are used on the leading face of the shaft tail stop diameter as they will protect the vacuum seal lip from sharp metal edges as the shaft exits the seal at high velocity. As can be seen below the Taimen uses such bushes on all its spear tails. A historical note is the Taimen had a front tied spear, bare tail shaft version that required a very simple muzzle seal, however that muzzle has ceased production. Another bare tail spear is the STC system, I don't like those although they have a newer rounded leading edge spear tail stop that is said to work with their system. I wouldn't think so, but Cressi have used it on the Saetta vacuum barrel version.

 

[popgun pete]

Any new slider has to interact with the shaft tail stop. This is where hydraulic dampers come into consideration as the body of the slider can be made to be a mini-water pump. A problem that needs to be considered is the sliders jamming on the shaft tail as they can be hard to pull off again.