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Old 01-09-2022, 04:12 AM   #1
vstante
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Ermessub MVD double roller mech

Hi guys, hope you all doing great!

I am looking for a Ermessub double roll mechanism for MVD handle. Its sold out on Ermessub page, do you have any idea where to get one?
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Old 01-19-2022, 02:14 AM   #2
spearq8
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Re: Ermessub MVD double roller mech

Much better is to just get the new Ermessub handle + trigger combo. The handle is designed specifically for the new DR trigger. I am not sure if he sold out of his production run, but if not ... that is a really good option.
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Old 01-23-2022, 05:08 AM   #3
vstante
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Re: Ermessub MVD double roller mech

Hi Majd, thanks! Well I bought a short Mvd gun, it was cheap.
It already has a handle so i tought I'd replace only the mech.
I wrote to Mario and he is sending me a DR mechanism for hunt and MVD handle. He is not sold out he told me.
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Old 01-28-2022, 01:54 AM   #4
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Re: Ermessub MVD double roller mech

Yes, I think the time of designing "fixes" for bad triggers should be over. Even with the Pathos triggers which always sell out when he makes them. The problem is that you have to deal with many different people, with varying DIY abilities ... trying to make the trigger work and modifying the handle accordingly. Some are very good at it but some are not and need to be helped through it. Much easier is to have a handle with a good trigger designed for that handle. No modification needed at all ... just remove one or two screws holding the pipe to handle and change out the handle and you are done with the mod. Also the new Ermessub handle is designed properly ... very high in the CG of the gun and recoil goes into the palm ... not thumb. Add to that the latest DR trigger and it should be a good transformation to any pipe gun that fits that handle.
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Old 09-23-2023, 10:09 AM   #5
vstante
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Re: Ermessub MVD double roller mech

Hi guys! Have been using the Ermessub Hunt/MVD now for
A year and it works great!

I have seen the MVD now also produce a double roll mechanism for the MVD handle. Has anybody tested it yet?
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Old 09-23-2023, 10:11 AM   #6
vstante
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Re: Ermessub MVD double roller mech

The pic...
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Old 09-27-2023, 01:10 AM   #7
doyenofcastle
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Re: Ermessub MVD double roller mech

is it same salvimar HEAVY METAL trigger ?
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Old 09-27-2023, 08:27 AM   #8
popgun pete
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Re: Ermessub MVD double roller mech

Quote:
Originally Posted by vstante View Post
The pic...
Looks like more metal has been taken out of the housing to reduce its weight. A problem with these mechanisms, not just the Double Roller, is they tend to be heavy and add weight to the rear handle.
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Old 09-27-2023, 09:06 AM   #9
spearq8
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Re: Ermessub MVD double roller mech

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Originally Posted by popgun pete View Post
Looks like more metal has been taken out of the housing to reduce its weight. A problem with these mechanisms, not just the Double Roller, is they tend to be heavy and add weight to the rear handle.
The next generation trigger might be using MIM box. Already in the DR trigger the trigger sear + shaft sear + line release ... are all MIM. With a MIM box you can actually do a computer analysis of the loading cycle, then you can remove all metal that is not being stressed and make the areas that are stressed thicker and stronger ... plus can add reinforcing bars connecting the box and making it much stronger. So no longer do you have to use a 2mm box and bend it ... you could in some areas use just 1mm and in others 3mm. Plus you can intricately provide channels for spring wire ... can really improve the design and functionality with more efficiency. On my computer I was able to remove 50% of the weight while making the box much stronger.

Another additional weight reduction can be done by simply changing the metal used. Titanium grade 5 or 6 or Ti64 is about twice as strong as 316 SS ... and weighs almost 50% less. Titanium is also much more corrosion resistant. While it is possible to use MIM for Titanium ... the temperatures required are extremely high and would need very expensive molds (much more than SS). I did do several trigger in Ti64 by metal 3D printing to test the idea ... and they worked amazingly well. Obviously 3D metal printing is not cost effective, but I wanted to test the concept.

Here is a Double Roller Trigger I designed and 3D printed for a C4 Urukay speargun. I made several in SS and 2 in Ti64. You can see the weight difference of SS compared to Ti64. I forgot how to do a direct video link, but there is a short link of me dry firing the trigger below.


https://youtube.com/shorts/7JkYkfB-LHg?feature=shared
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Old 09-27-2023, 04:38 PM   #10
popgun pete
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Re: Ermessub MVD double roller mech

Cam lock trigger mechanisms are light because the levers interlock against each other, so the only requirement is to tie the pivot points together to stop them spreading apart under load from the locked condition. There only remains the sear box roof to hold the spear tail down. Even this last requirement can be avoided by square cut sear lever teeth, hence you get trigger mechanisms like those used in the Aquacraft/Bandito spearguns with a plastic sear box being part of the stock/handle structure. Another example is the Ocean Rhino. In the Scubapro Panther the sear box roof becomes the pivot pin support as well, but it is no lightweight because it uses large levers in profile view as it fills a predetermined stock shape in the grip area.

By comparison frame lock trigger mechanisms need the pivot pins tied together and the resulting frame to lean against to restrain their trigger piece from revolving, thus providing a "lock" condition. Due to design errors some cam lock trigger mechanisms became frame lock mechanisms by accident thanks to the cast alloy grip handle era when unnoticed that is what locked up the trigger mechanism. An example where it was no accident was the Balco Sub Thunder grip, much like the JBL/Voit in grip shape. The eurogun shaft tail with its angled or rounded sear tooth accommodating tail notch will jump the sear tooth without a roof, so it needs a strong roof that is integrated with the sidewalls tying the two pivot pins together. This design came about as euroguns originally had rectangular sear box mouths and the anti-shaft rotation flat on top of the tail was pressed up onto the sear box celling created by the sear box roof. To stop the shaft tail wobbling from side to side they relied on the flat top tail being clamped by the band load up onto the ceiling of the sear box roof. The sear box mouth was rectangular because the line slide stop lugs were right at the rear of the shaft and were pushed back into the sear box with spear loading. These lugs or shaft ears were moved forwards when it was realised a strong fish could snap the spear tail off at the wishbone notches, so the lugs were then placed forwards of the wishbone notches where they remain to this day.
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Last edited by popgun pete; 09-28-2023 at 04:42 AM. Reason: added a photo, more info
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Old 10-30-2023, 09:23 AM   #11
vstante
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Re: Ermessub MVD double roller mech

Tnx for all the replies!
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Old 10-30-2023, 11:20 PM   #12
popgun pete
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Re: Ermessub MVD double roller mech

This new MVD Double Roller is not a floating tooth mechanism like the Ermes Sub trigger mechanism is, so it will not drop the force line of the spear pull like the Ermes Sub DR mech does. A pretty flat trigger mechanism though.

https://www.ebay.com.au/itm/115699530971
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