Changing/Removing/Installing a Rob Allen Trigger Mech

[Mr. X]

Changing/Removing/Installing a Rob Allen Trigger Mech cassette

My new trigger mech. showed up last night. I was concerned that it might be tricky having to deal with corroded metal & plastic with brutal force. However nothing could have been further from the truth - it was quick and easy.

The RA trigger mechanism is a suprisingly small plastic cassette. When I say plastic, this is not some flimsy packing plastic but thick, fancy fibre reinforced tough stuff.

The mech. is held in place by a single straight plastic pin behind the trigger & below the safety catch. To pop-this out use a long thin punch or long, straight 2.5mm Allen key(/wrench) and simply push with your hand using a slow, steady push -- no need for a hammer. The cassette can then be gradually manipulated out by hand - a small, flat screw driver might help get it moving.

Wash it out (there was some fine grit/sand around mine). Insert the new cassette & re-insert the plastic pin. That's really all there is to it. Had I known, I might have occasionally removed the cassette for cleaning (e.g. after particularly gritty seas).

Piece of cake

 

[Mr. X]

New mech vs. old mech (Vecta handle)

I had one of the very early RA Vecta handles on Sparid railgun. Examining the new trigger mech. cassette, it is clear that there have been some significant changes [see below].

For example:

-the stainless steel seer is a completely different design: smaller, shinier, a different shape & less visible. My old seer had two patches of corrosion, I suspect the new shinier steel will be more resistant to corrosion.

- the spear line-release is now spring loaded. Probably not necessary for the heavier stainless steel releases but my lighter plastic release started staying up, making loading difficult - so this is a welcome enhancement.

- the spearline hook is wider and flat at the bottom, not a sharp tooth like the old one (I was concerned about the strength of the latter - but it performed well and showed no sign of any wear).

- I'm told the new plastic parts use a different material to reduce friction & fluffing.

- the plastic pivot pins were black, now grey - probably use the new materials that reduce friction(?)

The sound and feel of the mech is noticeably different, both when loading and releasing. The original sounds more substantial (perhaps because the larger seer was moving more) but the new mech. seems quicker, lighter & crisper to engage & disengage.

 

[Mr. X]

Dismantling the old RA trigger mech / inside / parts

While I felt disinclined to dismantled the new RA trigger mech, I did want to see what might be wrong with the old one. It proved surprisingly easy to dismantle the cassette & re-assemble. I don't think I would encourage folk to do this but I thought you might find it interesting to see what's the inside of the old mech. looks like [see below].

There is actually nothing visibly wrong with any of the parts shown. The seer had some cosmetic rusting in two areas and some mild wear where the spear engages but nothing significant enough to cause any failure. Discussing with RA, it sounds like the fibre reinforced plastic in the original probably became worn and fluffy (due to release of fibres from the plastic surface) as I had encountered particularly gritty water conditions on several occasions last year (on one occasion finding 4 mini pebbles drop out of the trigger mech., several days after what I thought was a thorough cleaning, when I gave the gun a good shake).

The issues I encountered were:
- difficulty loading the spear into the mech. sometimes (this was I think due to the line release not dropping back into place due to fluffing).
- occasional release of spear while loading (again probably due to parts not slipping back into place properly due to fluffing)
- safety usually stuck (ditto) BTW push down, against the spring, when changing the safety position - this will unlock the slider at the back.

[Note: this "fluffing" is not visible].

 

[Mr. X]

Now...were are all those mullet! Here fishy, fishy, fishy...

 

[Mr. X]

I found this on the Rob Allen Portugal website . It shows a cross-section of the inside of a mech:

The seer appears to be the older-style and there is no spring visible on the trigger but the spring-loaded line release appears to be the new version. Also, it has a stainless steel line release hook.

 

[Marwan]

glad you have that sorted X, just thought id drop in and let you know youre not talking to yourself
cheers

 

[SinglerM]

Hey Mr. X,

I just bought an RA Caranx, it came with the old style trigger assembly. I just took it out of the grip frame and compared it to the pictures you posted. Is this something I'll have to upgrade soon due to the fluffing you described? or are the new triggers being phased in as the stock of old ones are depleted?
was it drag and corossion that prompted you to to upgrade, or some sort of recall?
the trigger assembly is held in using a stainless pin instead of plastic on mine, but it has the old style/larger seer.
Does the side panel that says "Vecta" indicate which version of trigger is used? Mine is molded plastic, yours has a sticker instead. Just curious about what, if anything I need to change.
Thanks for your help on my other thread.
Regards,
Mitch

 

[Mr. X]

Thanks Marwan. I didn't necessarily expect any response (although it's welcome of course), it is an informational thread.

SinglerM, I think the moulded side badges are newer models. No, there is no recall. The old ones generally work fine I believe. In fact, I think the older version has a more solid feel & sound. Although I wash my gun after each use, I did encounter some unusually rough, gritty entries last year - a lot of sand suspended in the water when I first entered the water. I usually dive in murky water (I'm worried that my new 75cm gun might be too long!).

I wouldn't worry about it unless you start getting problems, as I did towards the end of last season (see above list of symptoms). If it happens, you'll know it. They'll probably continue to refine the mechs., so you might as well wait until necessary. Having read this forum for several years, it seems most owners never have a problem. The RAs have a long warranty period & even after that, you can still buy the mechs. at a reasonable price.

[I suspect that guns with the optional stainless steel spear-line release will not experience the loading problem, because of the extra weight & smoothness of the hook].

 

[Mr. X]

From the RA website:

"The Rob Allen Vecta Mechanism is moulded from PA6 30% GS glass filled Polyamide to handle the power needed to hunt large bluewater fish. External shrouds and an internal barrel spigot increase strength at the critical barrel/mechanism interface. Apart from safety considerations, any flex in this area reduces accuracy. Internal webs at several places in the mechanism are designed to spread loading away from high stress areas.

All load bearing pivot pins as well as the sear are manufactured from solid stainless steel. The rubber overgrip is clamped in place by the cheekplates to prevent twist on firing. The spring loaded line release cam returns to position after firing for ease of loading.

Stainless Steel line release hook comes standard on all carbon guns.

(Code MECHSIR)"

 

[tuco]

Thanks for the info here posters.

Hopefully getting a caranx 120 this week

 

[3Vu]

Hi Mr X,
Nice pix, don't know y i couldn't take it apart.
I got the pin out, but could lift the trigger mech out. i used a screw driver to lift the end where uload up, but the other end was stuck and i did't want to force it open. so i prayed it with wd40 and soaked it in the bucket of water. i hope that would b fine.
Also site on roballen.co.za didn't show any length of 16mm rubber to 90cm gun (well i couldnt' find any for any gun) Can you send me the site if u know pls. Ta

3Vu

 

[Mr. X]

I guess we addressed 3Vu's quest on this thread: http://forums.deeperblue.com/spearguns-accessories/64443-rob-allen-opinions-2.html
- although this thread would have been a good place for it. [Warm/hot water might help loosen things up.]

 

[3Vu]

Mr X,
U are dead rite, it does loosen things up easier, as i dont see any more salt residue and n it clicks in better now when i load the shaft. sweeet, now i am just waiting for the band to come on ebay then try it out this weekend or maybe next weekend, Can't wait. Cheers mate.
3Vu

 

[Mr. X]

New image:

Looks like there is a new Sear & a new line release design. The sand block feature, above, is interesting too (it needed it). I'm surprised at how often they change the design of the trigger mech, same basic parts but in different arrangements and/or with different shapes. But good to see they are constantly striving to improve things. Perhaps they should take a look at the Omersub Cayman's constant tension trigger mech? (Haven't had any problems with my Omer XXV - touch wood.)

Also see this thread on the 2010 version of the mech: http://forums.deeperblue.com/euro-s...ob-allen-vecta-mechanism-photos-enclosed.html

 

[hteas]

Any thoughts on whether there have been enough changes to make it worthwhile to upgrade from my old green handled guns?

 

[Mr. X]

IMHO If your green handled gun is still working fine, stick with it
I changed my Vecta mech. because the old one stopped working.
If it ain't broke, don't fix it.

 

[hteas]

Pretty much my thought. just checking, since both handles are 12 years old.

 

[Mr. X]

Related thread here: http://forums.deeperblue.com/threads/updated-rob-allen-vecta-mechanism-photos-enclosed.86622/

Looks like Rob Allen & Jeremy continue to innovate, refine & improve - see Vecta 2 handle @ 4:40: