Home | Tournaments | Calendar | Weather | Merchandise | Sponsors |
|
All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here! |
|
Thread Tools | Rating: | Display Modes |
02-21-2020, 07:57 PM | #181 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Meandros have their own roller tooth trigger mechanism, but here it looks like the roller tooth engages the side slots in the housing, so this will need the eurogun ramped or curved spear tail notch to work.
|
03-11-2020, 07:39 AM | #182 | |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Quote:
There is another gun remaining that is identical to this one, but it has no hardware mounted even though the gun body is completely finished with camo paint and the name stencilled on. Last edited by popgun pete; 03-11-2020 at 08:51 AM. |
|
06-08-2020, 04:26 PM | #183 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
As someone asked for it elsewhere here is the Beuchat Mundial trigger mechanism. It is one of two dipping sear tooth trigger mechanisms, the other was produced by Sporasub. As they both held the patents their guns worked OK, but copyists had to make changes and their own guns were more troublesome. The curved slots that controlled the sear tooth movements were in the metal inner cage of the Beuchat design and in the sear lever itself for the Sporasub version, hence in the latter the sear lever slid on a stationary pivot pin.
|
07-27-2020, 05:35 PM | #184 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
The main reason for adopting reverse triggers is that they are shallow and can allow the grip handle to sit higher up so that the spear axis is not far above your hand. The downside is that they only dry fire thanks to the weight of the sear lever arm as they usually have no biasing spring on that arm. Exceptions are the Sea Hornet and Biller which use a leaf spring to bias both levers, but that deepens the mechanism housing. If you want more band draw then you need a longer gun. It would be possible to bury a standard trigger in the speargun grip and fire it via a remote trigger from in front of the grip, much like a mid-handle gun using a short link or pushrod. From memory Omer tried this with a gun where the trigger pushed on a second trigger or locking arm snugged in just behind the externally visible trigger.
The sear lever pivot pin position with respect to the sear lever tooth determines how readily the sear lever rolls. On standard mechanisms it usually sits below and just behind the tooth, but on reverse mechanisms it can be found further back. This may tend to cause drag on the tooth as the sear lever tips through a smaller arc, unlike standard mechanisms where the sear lever tips through a much larger arc to let the shaft go. The adoption of roller tooths will lessen this dragging as the spear tail rides up the tooth on the roller, the actual "tooth" being the cup that the roller sits in on the sear lever. Angled spear tail notches, i.e. eurogun shafts, will push the roller tooth down, square cut tails need to act on the cup, thus the roller tooth has to be free of the housing to ensure that it is not caught on any imprisoning housing side slots. Last edited by popgun pete; 07-27-2020 at 08:42 PM. |
07-28-2020, 12:52 AM | #185 | |
Registered User
Join Date: Mar 2015
Posts: 482
|
Re: Trigger Mechanism Design Rules
Quote:
|
|
07-28-2020, 01:22 AM | #186 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Durability depends on extent of use and how well guns are maintained. Everything wears out eventually, but some never put a lot of shots through their guns, so short of accidents the mechanism could last for decades and different owners. Because manufacturers don't expect guns to be molly coddled they make them to be reasonably rugged and they only need some occasional rinsing to get salt and sand out. For long term storage cleaned parts only need a shot of WD40. Over loading and using the mechanism as a vice while removing hard to budge speartips can bend parts, so is not recommended. The sear tooth only holds the shaft while the spear tail cannot jump over the top of it, hence the nip of the sear box roof should not be compromised nor axles bent.
Mechanisms with plastic parts after careful design are reasonably durable if the gun is kept within its design limits, copies made by pirates maybe not so durable when they have no idea what they are copying and what it is actually made from, plastic ain't always plastic, but they don't care about that. If you buy from someone who has a reputation to keep then the products will be good, provided they did their homework such as testing and durability assessments. Few guns have come out with rubbish mechs and they were almost immediately binned once the word got out. |
09-06-2020, 01:15 AM | #187 |
Registered User
Join Date: Mar 2015
Posts: 482
|
Re: Trigger Mechanism Design Rules
Does salvimar revised their metal trigger in the last 4 years ? I read other posts in 2016 discussing the salvimar first metal trigger and many comments was comparing the thin roller pin to ERMESSUB and how salvimar was weak , recently there is trigger called Heavy duty metal from salvimar , I have seen their speargun tomahawk and hero is widely used in my place and many guys said its very accurate and smooth,but gun setup 6.5 mm /7 mm with 2 pair of rubber ,I am not sure if it can be used for building a wood gun with 3 rubbers ,anyone try that trigger for long time ?
|
09-06-2020, 03:27 AM | #188 | |
Registered User
Join Date: May 2009
Posts: 3,292
|
Re: Trigger Mechanism Design Rules
Quote:
You cannot compare the new Ermessub triggers with the Salvimar. The Salvimar Metal trigger has a 2.5mm roller while the Hero roller is a little more at around 3mm ... compare that with the Ermessub which is 6mm and it is obvious that the 6mm roller will distribute load much better at high loads as the roller has much larger surface area to work with But the main problem with the Salvimar trigger is that they have incredibly poor tolerances. I measured the shaft sear pin hole at 4.15 mm !!! and they are using a 4mm pin for that sear. Roller triggers need very high tolerances so that the rotational contact is precise and ideally you want to have between .02 to .04 mm tolerance between pin and hole. With the Salvimar trigger the loose tolerance allows the entire sear to move forward and thus the rotational contact gets screwed up and the shaft sear gets jammed into the trigger sear and doesn't allow it to function properly. I have a few of those triggers and I found a very simple fix. If you have a lathe, just take a 5mm 316 SS rod and shave it down to 4.12 mm and use that as your trigger sear pin. Of course you will need to slightly enlarge the mech box pin holes to allow for the larger diameter pin. This is a good solution if you want to upgrade a pathos speargun as the Salvimar Metal handle is dramatically better design than the Pathos and once you fix the trigger it really is a great upgrade to any Pathos pipe gun. Locally I can get those handles for less than $20 with trigger ... they are being sold cheap as they are seen as defective, but once you fix the trigger they really are a great bargain. |
|
09-07-2020, 07:10 PM | #189 |
Registered User
Join Date: Jan 2007
Location: North Miami, Florida
Age: 58
Posts: 2,868
|
Re: Trigger Mechanism Design Rules
Hero trigger works fine. Metal doesn't.
__________________
Marco A bad day fishing is ALWAYS better than a good day at work |
09-24-2020, 01:58 AM | #190 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Someone recently asked me about the Ermes-Sub double roller and its gearing advantage which can be appreciated more if you think of the cupped cut-out in the sear lever arm as actually being the sear tooth. That means it is on a line with the sear lever pivot pin at the rear. What pushes the sear lever down is the fact that the cupped cut-out is effectively an angled tooth which directs a component of spear pull force downwards. You can think of the spear tail notch and intervening roller as a single part pushing on the sear lever, then once it rolls the two components separate. Wear on the roller and cupped cut-out "tooth" remains to be seen in the long term when used in the sea. Clearances are now not just the nip between the sear box roof and sear tooth top, but between the sear box roof, roller and sear lever cupped cut-out, it being the effective “tooth”.
|
06-27-2021, 09:18 PM | #191 | |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Quote:
|
|
07-01-2021, 09:32 PM | #192 | |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Quote:
|
|
11-07-2021, 07:14 PM | #193 |
Registered User
Join Date: Sep 2003
Location: Tampa
Posts: 2
|
Re: Trigger Mechanism Design Rules
Ummmmm i need help reassembling my AB Biller safety…. Any help??
|
11-08-2021, 01:46 AM | #194 | |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
Quote:
Reassembly is the reverse of removal, it can be a bit fiddly to do, but is not that difficult once you have a suitable rod to depress the plastic red bush and an awl to manipulate the wire circlip. Last edited by popgun pete; 11-08-2021 at 02:17 AM. Reason: Added a diagram to show the parts and where they go. |
|
11-08-2021, 02:09 AM | #195 |
Registered User
Join Date: Mar 2006
Posts: 4,245
|
Re: Trigger Mechanism Design Rules
To save you looking it up elsewhere here are the safety cam positions.
Last edited by popgun pete; 11-08-2021 at 02:12 AM. Reason: added a photo |
Bookmarks |
Thread Tools | |
Display Modes | Rate This Thread |
|
|