New roller trigger Salvimar 'Metal'

[Kodama]

Recently I have been on the lookout for another speargun to enlarge my arsenal.
Salvimar has been high on the list and now that they have come up with this new roller trigger I am completely intrigued.
http://www.salvimar.com/legginews.aspx?IdNews=60

On another forum there is a super interesting discussion going on about roller triggers. I would have loved to participate but somehow my account never got activated and it's impossible to contact anyone.
Anyway I wanted to ask the question here.

Has anyone used these new 'metal' roller triggers and what do you think of them? Trigger build quality is always one of my main concerns while choosing a gun.
I would love to hear your thoughts if you have any experience with this trigger or with any other roller trigger out there. I am especially looking in the direction of the gun builders on this forum.

To me the concept makes a lot of sense and this particular trigger seems pretty wel designed but without any user reviews or particular experience I am not yet convinced.

Your thoughts?

 

[popgun pete]

If it is well made then it should be OK as the roller will be on the correct arc and the roller axle is short and should not bend. The roller face needs to sit square to the surface that it rolls on or it will have a point contact rather than a line contact from side to side of the roller. With curve matched parts the contact is longer (wider) than a thin line from side to side, the sear lever tip being stationary and featuring an arc segment "hollow" that the trigger top cam revolves or slides through, the trigger being the moving element until the surfaces lose contact and then the sear lever can roll and release the spear.

 

[Kodama]

Tomorrow I hope to get the chance to inspect the trigger myself. Thank you for your explanation.
I wonder if a roller made out of UHMW would be an option. Silent and great wear resistance.


Sent from my iPhone using Tapatalk

 

[popgun pete]

I think that pressure from the high contact loading would distort a non-metallic roller and then it would skid. Also any flattening of the roller would slightly change the lever geometry and tip the sear tooth forwards at the locked condition.

 

[Kodama]

Interesting line of thought. Indeed it should not be able to deform but I wonder if that would be the case anyway. A roller on an axle could be deformed more easily than a solid floating roller I suppose. Depending on tolerances of course.
Because of its unique properties it might be worth experimenting with it nonetheless. As far as I can understand deformation might only be an issue under high temperature. Can't really find any numbers to support this claim though.


Sent from my iPhone using Tapatalk

 

[popgun pete]

You could just make a roller and load it up to find out, you don't need a trigger mechanism, but the contact pressure will be concentrated in a straight line across the width of the roller.

A reference: https://www.kmsbearings.com/media/wysiwyg/pdfs/UHMW_properties.pdf

 

[Kodama]

That would be a worthwhile experiment.


Sent from my iPhone using Tapatalk

 

[Huntsman89]

Hii!! Before I got into spearfishing I was big into airsoft, had a tokyo marui vsr10 that I upgraded and one such upgrade was a trigger system called zero trigger. The trigger was made strong enough to handle an m190 spring (m meaning meters). So basically the trigger could handle 190 meter per second spring which is a pretty strong spring. The reason why I brought this up is it basically is a roller trigger and the internals is pretty basic just to give you an example of a simple design if you were intrested. Heres a link to a short video that sort of explains how it works best one I could find that describes how it works and operates.

 

[popgun pete]

Trigger mechanisms for spearguns have to to deal with 100 to 200 pounds of band load pulling on the sear tooth, sometimes more, so they are not really like that PSS 10 Zero Trigger, although the basic elements are similar. I had a look inside one of them here: http://www.airsoftsniperforum.com/41-vsr-rifles/8897-laylax-aa-zero-trigger-spring-fix-guide.html

An interesting development is the "Roll System" used by Ermes Sub where the sear tooth is a roller that sits in a cut-out "cradle" on the sear lever where the sear tooth would normally be. This roller tooth is not actually connected to the sear lever, instead it has an axle passed through it that moves in curved slots flanking it on either side that are cut into the sear box walls. When band pull load is applied to the "roller tooth" it is restrained by both the side slots and the rocking sear lever cradle underneath, so the mechanism side walls take some of the load with the remainder of the load acting on the sear lever just winning out in a contest where the sear lever is still pushed downwards when the trigger is pulled. The "Roll System" works with both standard and reverse trigger mechanisms, but how long it works will depend on the side slots and the projecting axle ends on the roller tooth that engage those slots. You can think of the sear tooth roller as somewhat like a kitchen rolling pin.

 

[Huntsman89]

I totally agree with you Popgun Pete, as the zero trigger would not be the best. I just saw roller trigger for spearguns and thought I might add in the zero trigger as some sort of idea if any one was intrested in designing one, as the basic mechanics are there. Im still fairly new to spearfishing and recently started getting into rollers. I purchased an ermes sub testata roller head as it was the closest to a manny sub that I could find that came with glass bearings and for 109$ I would say it was a good purchase for me. Im a tinkering type of person so my set ups usually change from time to time. Planning on getting me an inverted roller to complete my growing collection.

Cheers, Eric

 

[bucanero]

Hello and Greets from germany i have to tell a Thing about Roller Trigger Mechanismus .I have an older first Generation Abellan Albacora 105 cm bandstech very heavy gun and i love it, very fine Gun for the mixed conditions in south oft creete . But i always wanted to improove it a bit so i looked also at the Dapiran Website for new inventions and found out some Day that the Trigger in my Abellan was made by Master Dapiran...and that Victor Abellan started to build Spearguns with the Support gom Mr. Dapiran so far so good ..as we say here one day i saw that he had developed a New Trigger Mechanism and he called it 'meccansmo scangico rollino' and luckyly it fits in my old thunder stick an i will buy it one day ..this was about 2 1/2 jears ago ... Dapiran says that it is not the most important development he made in his Spearguns but that the trigger pull is much sweeter now what ever that means... He has some videos fom its new guns on vimeo an it looks impressive how straight they shoot..
So this was my 2. reply and i have to excuse for my bad english and my orhography regards ..and many fish to all of you..

 

[popgun pete]

I found it here: http://www.dapiran.it/web1.5/index....ection&layout=blog&id=4&Itemid=100028&lang=it

 

[bucanero]

Here is a Link to two of the Dapiran Videos

I have an imagination of less side movement (vertical axis) caused by the reduced force of triggerpull ,but it is only my personal imagination...