Home Tournaments Calendar Weather Merchandise Sponsors

Go Back   Spearboard.com - The World's Largest Spearfishing Diving Boating Social Media Forum > Spearfishing Gear > All About Guns

All About Guns What's your weapon of choice, and why? Discuss the beloved speargun here!

Reply
 
Thread Tools Rate Thread Display Modes
Old 10-22-2022, 02:50 AM   #1
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 482
Fix a roller trigger

I have given that trigger from my buddy after a bad diving day he was not able to shoot , when we removed the trigger we notice the roll cylinder was removed and the pin was missing ,I have an idea to replace the pin by Nickle alloy rod harder than SS316 but we have to weld that pin to the frame ,Not sure if I can give a tack TIG welding in one side only or is their any other suggestion ?
Attached Thumbnails
Click image for larger version

Name:	1666424412259.jpg
Views:	201
Size:	145.5 KB
ID:	248619   Click image for larger version

Name:	1666424412223.jpg
Views:	209
Size:	135.4 KB
ID:	248620  
doyenofcastle is offline   Reply With Quote
Old 10-22-2022, 05:13 AM   #2
popgun pete
Registered User
 
popgun pete's Avatar
 
Join Date: Mar 2006
Posts: 4,245
Re: Fix a roller trigger

You could center punch the end of the pins to make them tight in the mounting holes, which is what they do on the main pivot pins, after you install the roller.
popgun pete is offline   Reply With Quote
Old 10-22-2022, 05:49 PM   #3
kavachi
the deeper the blue.....
 
kavachi's Avatar
 
Join Date: Oct 2016
Posts: 498
Re: Fix a roller trigger

yep, that can happen with all the pins on the older DR mechs, hence Mario using fixed threads now

just cut piece of matching diam 316 stainless, 2mm longer than the outer sear width, and as Pete says, centre punch both ends so they splay out enough to remain captive.

if doing this for the pins that anchor the sears in the mech box, need to ensure the replacement pin's just the right length to splay out at the ends - too short will squeeze the box and prevent sears moving freely, too long and the mech wont fit back in it's pocket
kavachi is offline   Reply With Quote
Old 10-23-2022, 02:52 AM   #4
spearq8
Registered User
 
spearq8's Avatar
 
Join Date: May 2009
Posts: 3,292
Re: Fix a roller trigger

Not sure I have seen this trigger before ... but I don't like how they have crimped the pins of the box. The box is probably 1.5mm and those pins look like they have a cavity that is about 1mm ... so that means the trigger sear and shaft sear are held by about .5mm of working pin ... I certainly would not want a big load on that. You want sear and trigger pins to be held by a full bore pin with no weakness! As for the front roller, with the Ermessub DR triggers we made it so that the PIN of the trigger sear can float freely and it would not come out because it is constrained by the sides of the box. The movement of the shaft sear is constrained by not only the box but also by the line release. So once installed it cannot come off. So the box internals would be say 10.4mm and the roller sear would be 10mm with a PIN that is around 10.2mm. So the PIN could move aound side ways with no problems as it is caged inside the walls of the box. Mario did have some triggers using 8mm sears for a while ... on those he would hammer the ends of the pins to flare them out ... but that is just a horrible way to do things as you can easily bend the pin and the roller will not turn properly ... also if the pin comes out you have a dangerous misfire possible. Salvimar have a non caged pin on their roller sear, but it is crimped in with a specialized tool where the roller cannot possibly go out.

To fix this you need to see what the hole of the pin is and get something that is about .05mm smaller. TIG welding is risky unless you really have a good TIG welder and you know how to set it to spot welding. I have spot welded some pins before and had to throw away a lot of sears while doing that. I would just cut the pin to where it exactly match the surface of the sear and then use a center punch and hit two hits to the edges of the pin. The idea is to make the pin go thicker on the end and cover the .05mm difference.
spearq8 is offline   Reply With Quote
Old 10-26-2022, 08:15 AM   #5
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 482
Re: Fix a roller trigger

Quote:
Originally Posted by popgun pete View Post
You could center punch the end of the pins to make them tight in the mounting holes, which is what they do on the main pivot pins, after you install the roller.
Thanks for your reply
doyenofcastle is offline   Reply With Quote
Old 10-26-2022, 08:19 AM   #6
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 482
Re: Fix a roller trigger

Quote:
Originally Posted by spearq8 View Post
Not sure I have seen this trigger before ... but I don't like how they have crimped the pins of the box. The box is probably 1.5mm and those pins look like they have a cavity that is about 1mm ... so that means the trigger sear and shaft sear are held by about .5mm of working pin ... I certainly would not want a big load on that. You want sear and trigger pins to be held by a full bore pin with no weakness! As for the front roller, with the Ermessub DR triggers we made it so that the PIN of the trigger sear can float freely and it would not come out because it is constrained by the sides of the box. The movement of the shaft sear is constrained by not only the box but also by the line release. So once installed it cannot come off. So the box internals would be say 10.4mm and the roller sear would be 10mm with a PIN that is around 10.2mm. So the PIN could move aound side ways with no problems as it is caged inside the walls of the box. Mario did have some triggers using 8mm sears for a while ... on those he would hammer the ends of the pins to flare them out ... but that is just a horrible way to do things as you can easily bend the pin and the roller will not turn properly ... also if the pin comes out you have a dangerous misfire possible. Salvimar have a non caged pin on their roller sear, but it is crimped in with a specialized tool where the roller cannot possibly go out.

To fix this you need to see what the hole of the pin is and get something that is about .05mm smaller. TIG welding is risky unless you really have a good TIG welder and you know how to set it to spot welding. I have spot welded some pins before and had to throw away a lot of sears while doing that. I would just cut the pin to where it exactly match the surface of the sear and then use a center punch and hit two hits to the edges of the pin. The idea is to make the pin go thicker on the end and cover the .05mm difference.
Hammering the pin will bend it
doyenofcastle is offline   Reply With Quote
Old 10-27-2022, 12:54 AM   #7
spearq8
Registered User
 
spearq8's Avatar
 
Join Date: May 2009
Posts: 3,292
Re: Fix a roller trigger

Quote:
Originally Posted by doyenofcastle View Post
Hammering the pin will bend it
Yes of course if not done properly it will bend the pin ... very similar to flopper pin. If you go too far you will lock the roller. If you don't do it enough you risk having the pin come off and you have the two arms of the two thin arms of the shaft sear acting like a friction trigger ... or maybe even the shaft sear will no longer mate with the trigger sear and you have a very dangerous misfire.

If you look at the Ermessub DR design the movement of the roller pin I actually simulated the movement of the front roller pin to make sure it never comes out of the box throughout its movement cycle. Once you install the line release the movement of the shaft sear is confined and thus you can keep a free floating pin on the roller. This gives a double rotation for the roller and really makes the rolling of the roller much better and smoother.

In your case though, that is not possible as there is a cut in the box that would allow the pin to come out and it seems that the shaft sear is an 8mm shaft sear in a 10mm box (poor design). Thus you have to risk either hammering the pin in without bending it ... or get someone who is really good with TIG welding to setup an exact setting for the TIG welder to allow a tiny spot weld between the pin and the shaft sear. I did try TIG welding and I ended up screwing up a few shaft sears while setting up the perfect settings... but then again I suck at TIG welding. One safe idea might be to have a longer pin that sticks out the sides and then TIG weld the ends of the pin and then just sand it down. Hopefully the ends of the pins would be like a "bulb" and will not come out.

By the way what trigger is this??
spearq8 is offline   Reply With Quote
Old 10-27-2022, 02:01 AM   #8
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 482
Re: Fix a roller trigger

I am searching for a laser welding shop ,I have nickel pin and I think 316 to nickel welding is ok or I just use a 316 pin if galvanic corrosion can affect but nickel is stronger than 316 .
doyenofcastle is offline   Reply With Quote
Old 10-30-2022, 01:28 AM   #9
spearq8
Registered User
 
spearq8's Avatar
 
Join Date: May 2009
Posts: 3,292
Re: Fix a roller trigger

I don't think you can TIG weld nickel to 316 SS. You can probably braze them though. However I do think that is too much work. Just use longer 316 pin that is about .05mm diameter less than the roller hole and spot weld the extended end of the pin. It looks like you have an 8mm shaft sear in a box that is at least 10mm... just use a 10mm or 12mm pin on the 8mm shaft sear and use TIG welder to burn the end of the pin. The end result will be that your pin will shrink to about 9mm and the ends of the pin will be a bulb and thus much thicker than the pin and won't escape the shaft sear. If you need to reduce the pin width after TIG welding the ends just sand a bit off. Again this is tricky and you can easily weld the roller to the pin and scrap the entire shaft sear.
spearq8 is offline   Reply With Quote
Old 01-28-2023, 03:55 PM   #10
doyenofcastle
Registered User
 
Join Date: Mar 2015
Posts: 482
Re: Fix a roller trigger

I was able to find a guy who did the job without welding only flatten the pin from both side
Attached Thumbnails
Click image for larger version

Name:	IMG_20230128_145251.jpg
Views:	126
Size:	129.8 KB
ID:	248814  
doyenofcastle is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:00 PM.


The World's Largest Spearfishing Diving Social Media Forum Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2002 - 2014 Spearboard.com