Author Topic: Dbl set trigger problem (Read 11589 times)

magyar · « **on:** July 06, 2014, 07:22:33 PM »

Good morning all,

I am a little flummoxed..... my first build so I am getting used to it......

I have inlet the triggers but its not working properly. The main trigger will not trip the sear. My guess is it is not near enough to it and I may need to go deeper with the inlet. However, and this is weird to me, if I "set" the trigger and pull it, it still will not trip it.....on the first pull. BUT - if i set it and pull the trigger a second time, it will! What the heck is going on here?

Over all I am fairly pleased with this first build. Taken me longer than expected due to a heavy travel schedule and the need to, on occasion, walk away and think for a few days before continuing. This board has been extremely helpful every step of the way and I am sure you will be again now with this trigger issue. I am sure it is probably nothing and I am just not seeing it.

gunmaker · « **Reply #1 on:** July 06, 2014, 07:36:13 PM »

Mark the rear of the tgr blade with color, maybe it's slightly touching wood in there.....Tom

Acer Saccharum · « **Reply #2 on:** July 06, 2014, 07:45:02 PM »

1) Does the trigger work OUT of the gun?

2) does the lock go to half-cock, and full-cock OK?

D. Taylor Sapergia · « **Reply #3 on:** July 06, 2014, 08:21:24 PM »

PICTURES!! ...an enormous help in diagnosing issues such as this.

Dave B · « **Reply #4 on:** July 06, 2014, 08:25:38 PM »

It sounds like you are having trouble with having proper sear contact. with the lock out of the stock and the trigger uncocked push the rear trigger forward. You should be seeing the rear trigger bar in the sear bar hole looking through the lock inlet portion. Do the same with the front trigger checking the amount of trigger bar being visible If you are not seeing it clearly the lock needs to be inlet deeper. If you smoke the trigger blades and install every thing back in place and operate the triggers. Take the triggers back out to check the points of contact. No contact on the front trigger blade indicates there is a problem with either a portion of the inlet is getting in the way or they just need to be inlet deeper.
I got a little carried away with this trigger inlet and you can see clearly the rear bar through the sear hole inlet. pulling the front trigger will reveal the same amount coming from the other direction.

PPatch · « **Reply #5 on:** July 06, 2014, 11:03:20 PM »

Sounds as if you are close... For the time being I wouldn't remove any more wood. When you believe you understand the solution and Perhaps do have to remove wood do so in small shavings, sneak up on it, assembling and testing often, otherwise you might end up having to shim the top of the trigger plate to lower the trigger unit back down creating more frustration. Hopefully someone here will turn a light bulb on for you and resolve the issue.

dp

bob in the woods · « **Reply #6 on:** July 07, 2014, 12:06:19 AM »

I have seen where there was wood interfering with the lock components, so that the 1st pull on the set trigger didn't fire the lock, but the 2nd did. Make sure that the lock is working freely [ sear included] in it's inlet. Then you can concentrate on the triggers.

Virginiarifleman · « **Reply #7 on:** July 07, 2014, 03:39:13 AM »

Bob, I have had to grind a little off the trigger blade if its high. this has worked for me in the past.

goodtime7 · « **Reply #8 on:** July 07, 2014, 06:19:22 PM »

For what it's worth, coming from a relatively low time builder...... I had the same problem recently. I think all the thoughts/ideas proposed are excellent. To test the issue of distance from the sear to the top of the trigger bar, I temporarily wrapped the sear with masking tape, several wraps actually. Put it back together: problem solved. So, at that point I decided I would build up the rear trigger bar, and did so by silver soldering additional steel to the top. Hit it right, and had minimal fitting to do afterwards. So, this "tape test" may be something to consider.

Looking back, I think I may have mis-positioned the trigger slightly, so that the arc of travel of the trigger bar was less effective. I really didn't have much latitude to deepen the inletting, so decided to build up the trigger bar. It is interesting that the DST triggers that Jim Chambers sells have taller trigger bars, so I suspect this has happened to others too. Davis also has some replacement triggers that might be an option too. Good luck....I'm sure as you think it through you will come up with a viable option.

whetrock · « **Reply #9 on:** July 07, 2014, 07:03:38 PM »

We are all assuming that the sear engagement on the tumbler is working like it should; that it will release smoothly with thumb pressure when the lock is out of the stock. That seems to me to be the first thing to check.

Beyond that, if the trigger has to hit the sear twice to trip it, then it sounds like the sear arm or some other part of the sear is likely binding on wood. Black the sear and other internal parts of the lock completely with candle black (soot), then, with the triggers out of the stock, put the lock back in and tighten the lock bolts down so that the lock is in its final position. Trip the lock by putting a popsicle stick sized piece of wood up in through the trigger hole so as to push on the sear arm, then take the lock back out and look for marks. Also check the lock carefully to look for spots where the soot has been rubbed off, then look again in the mortise to see if there are corresponding deposits of soot. You may need to do this several times. I've had better luck doing this with candle black than color transfer, as I find that I get transfer color on everything that I don't want it to get it onto. The soot transfers to the wood easily at the proper places. A candle with a long wick will produce plenty of soot for this. (You don't have to have an oil lamp.)

Once you are confident that there is no binding, then you can check to see if the trigger arm is indeed touching enough. You can tape the sear arm, like Good time 7 suggested, if there is room. Or you could superglue a shim of card stock (paper) to the top of the trigger bar. Don't glue or tape anything to the sides of the trigger bar, as added thickness there can create more binding.

As Patch said, don't inlet the triggers any deeper until you are confident that it must be done. And don't assume that just because you deepen the trigger that you must also change the wrist profile. Many old rifles have set triggers that are deeper than the profile. Or you can also just build up the trigger bar just a bit. But again, check lock function first. Then look for binding. Then check trigger bar height.

frogwalking · « **Reply #10 on:** July 07, 2014, 07:35:07 PM »

Forgive me if I repeat what someone else has said. I would try a number of things involving wood before modifying metal. First make sure the mainspring on the rear trigger is tight enough. These are adjustable for spring tension. Make sure the arm of the sear is long enough, and free to cleanly operate the lock. I do this by pushing on it through the trigger hole with a screwdriver while the lock is in the stock. If this works, then make sure the space for the trigger blades is adequately inletted. I just went through this operation on a new Tennessee rifle yesterday. My problem was the sear arm rubbing against the wood to the rear of the hole in which it operates. You can see this problem through the trigger inlet if you look carefully. In general, do the least invasive, things first, and leave the things that are really hard to undo for last.

Oh. If it turns out that you need to inlet the triggers deeper, there is a high possibility that your stock is too deep in this area anyway. While pondering this issue, determine where the ramrod hole is before removing wood unless you want a brass "wear plate" in this area.

whetrock · « **Reply #11 on:** July 07, 2014, 09:15:24 PM »

Quote from: frogwalking on July 07, 2014, 07:35:07 PM

First make sure the mainspring on the rear trigger is tight enough. These are adjustable for spring tension.
...

Yeah, Frog is right on target with his comment about the main spring of the trigger. That's another thing that we were all assuming was already okay.

Magyar, the spring has a bow in it, with the concave side down. It does not need to be so tight as to completely straighten out that bow. But it does need to be tight enough to make the trigger arm jump up like it is supposed to. Even a quarter or half turn adjustment in the spring tension screw will make a lot of difference in how hard it taps the sear arm.

magyar · « **Reply #12 on:** July 07, 2014, 09:22:57 PM »

Thanks everyone for your input. After marking everything, testing and retesting, I found that my trigger was not forward far enough. The sear was being caught, just barely, by the rear trigger plate but not at all by the front. I tried moving things forward 1/4 inch and we are good-to-go. I tightened the spring down and now the rear trigger hits with enough force to trip it each time.

However, there is still a good deal of "creep" in the front trigger. Much more than with my other single trigger rifles and fusils. I know this could be because the trigger bar is not seated close enough to the sear. I can fix this by inletting further I suppose. I would prefer not to build up the bar with solder as i know someone else who did and it ended up cracking over time (probably done incorrectly anyway).

Before i go and inlet further, are there any hard and fast measurements i should be concerned with in the wrist area? I dont want to do a "newbie" thing and leave it too thick and bulky looking. But at the same time, i dont want to be too aggressive and thin it out too much so that it risks cracking. I already fear that all the wood removed inside to make room for the trigger assembly is a little worrisome. Should it be?

Thanks again all for the suggestions and guidance. This forum is fantastic.

WadePatton · « **Reply #13 on:** July 07, 2014, 10:32:15 PM »

"Building up" any direct contact/wear surface with soldier is a bit silly. (like filling pot holes with mashed potatoes). Brazing or soldering a bit of steel in place would be my choice IF "corrective" bending were not applicable.

Great that you got it sorted. Some of these here fellas know what they're talkin' about.

Acer Saccharum · « **Reply #14 on:** July 07, 2014, 10:34:19 PM »

With a set trigger, when you want to use it as a single trigger(ie: the the DST trigger is NOT set), you should have a mile of free travel before the front trigger contacts the sear.

Once the front trigger contacts the sear, and you still have creep, that is in the lock itself.

But if you have a DST, who cares about a little creep?

(Dave Rase, I still care about you)

whetrock · « **Reply #15 on:** July 08, 2014, 02:05:21 AM »

Quote from: Acer Saccharum on July 07, 2014, 10:34:19 PM

With a set trigger, when you want to use it as a single trigger(ie: the the DST trigger is NOT set), you should have a mile of free travel before the front trigger contacts the sear.
…

Acer said it.
Yes, it is possible to fire the gun with the front trigger, but (IMHO) the main point of that feature is not so that you can use the front trigger to fire a load, but rather so that you can use the front trigger to lift the sear so as to lower the cock/hammer with your thumb.

If you are determined to work on the creep, first take time to think it through very carefully. It may seem that you could perhaps resolve some of it by either raising the entire assembly (deepening the mortise) or by building up the trigger bars (e.g., brazing on a shim of steel). But you need to keep in mind that the front trigger lifts a bit when you set the back trigger. (I have one here in front of me that lifts a full 1/8 inch.) That's how they work. And so, if you were to inlet the assembly in too deeply, or if you were to shim up the front trigger too much, you might then find that the front trigger bar was then too close, and that you could no longer set the triggers. It has to have room to do it's thing.

If you want to see how much the front trigger lifts while being set, pull out the triggers, then remove the trigger main spring (but leave the small spring in place), so that you can cock the rear trigger slowly. You will see that the front trigger lifts quite a lot as the engagement points of the two triggers pass one another and then slip into place. You cannot do away with that, and you therefore cannot resolve any creep that comes as a result of it.

Wrist shape. If you had a good blue print drawn out before starting this build, and if your wrist, etc. is shaped according to blue print, then I wouldn't recommend changing it. In my own work, I find I am usually satisfied with how things turn out when I follow a plan that I have thought through carefully and drawn out accurately to full scale. In contrast, I almost always dislike how things turn out when I start tinkering and adjusting mid-project. If you don't yet have a good plan drawn out, then now's a good time to draw one. It will help you with everything that hasn't been done yet.

Acer Saccharum · « **Reply #16 on:** July 08, 2014, 04:56:42 AM »

With a single or plain trigger when there is creep, you can feel it. With a DST, you lose all sense of the trigger/sear creep. Leave the creep alone.

(this doesn't mean I'm going to ignore you, Dave)

Dave B · « **Reply #17 on:** July 08, 2014, 05:48:37 AM »

I have a project that I was keeping slim through the wrist and tighter to the underside of the trigger area and have a problem with the very thing the guys are talking about with regard to needing the front trigger to be able to pop up a little as the rear sear of the rear trigger passes by the front triggers sear. When I cock the rear trigger the force needed to engauge it is too high due to the front trigger engaging the sear of the lock. Even with it this close there is still a whole bunch of creep and any closer would mean that I wouldn't be able to set the rear trigger at all.

whetrock · « **Reply #18 on:** July 08, 2014, 01:24:23 PM »

Yeah. You can't do away with the creep on the front. But if you shoot it the way it was intended, using the set trigger, then that creep on the front trigger is a non-issue.

If the front trigger is too high, so high that it can't pop up as required, then sometimes it is possible to trim down the top of the front trigger bar where it is touching the sear, so as to make room for it to pop up. The only reason the front trigger bar is long like that is so that it can reach up to the sear. So, if it is too high, it can be trimmed down a little. But, again, the point we are trying to make is that sometimes a deeper inlet just requires more trimming of the trigger later. Any "gain" you think you would make is immediately "lost" again when you have to trim down the trigger bar.

Another fix some people try for a front trigger that is too high is to bend up the sear bar or sear arm, but you can get into issues if you go that direction. The sear arm works best if straight and parallel to its pivot pin. (You can do some welding, or make a custom one from scratch so as to reconfigure the position of the arm, but it gets complicated.) And if you bend the whole sear bar up (between the pivot and the arm), then you sometimes get into conflict with the lower arm of the sear spring. These things all have their relationship, and if you tinker with one, you affect the others.

And so here's the point of all this: Raising the trigger assembly may not solve anything. It may only serve to create a whole new set of problems!

magyar · « **Reply #19 on:** July 08, 2014, 08:34:16 PM »

All good points guys. Thanks so much. i am leaving it alone. Acer is right. Why the heck use the front trigger alone anyway? I did want the set triggers for a reason.

Also a good point on having a plan drawn out for the wrist. However, this was a TOW "kit" and already shaped. Though i still needed to remove a good deal of wood. Had i started from a blank (which i am going to next time) i think i could have planned things a bit differently. But for a first-timer, this was the easiest route for me to mentally accept! Though after getting into it a bit i do think i could have handled starting from a blank.

By the way....any of you experienced builders ever planning or considering to do a class down around Lexington, KY at some point? I wish we had something down here like a KY version of the North House Folk School.

thanks again all.

Acer Saccharum · « **Reply #20 on:** July 08, 2014, 08:50:48 PM »

Quote from: magyar on July 08, 2014, 08:34:16 PM

I wish we had something down here like a KY version of the North House Folk School.

thanks again all.

If you cook, we'll come.

smylee grouch · « **Reply #21 on:** July 09, 2014, 05:22:52 AM »

Whetrock, can you tell me why you want the front trigger to pop up on a double set trigger? I want the rear trigger to pop up to disengage the sear but maybe I read your post wrong.

whetrock · « **Reply #22 on:** July 09, 2014, 04:57:12 PM »

Hey Grouch,
I'm glad you asked. Yeah, it's hard to understand a written description of a trigger! and I'm sure my explanations are hard to follow.
It's not that we want the front trigger to pop up, rather, it's that it does lift up as the rear trigger is being cocked (being pulled back into it's cocked position). It's a mechanical requirement of the design.
I've got a Davis trigger here. I'll try to take some photos and post them later. With photos, it will be easy to understand.
Whet

jamesthomas · « **Reply #23 on:** July 09, 2014, 06:19:08 PM »

Also, as an aside, if you can't set your lock off with just using your fingers try loosening the 2 screws that hold the insides of the lock together. My L&R Durs Egg was impossible to set off by just holding it and using finger pressure, then I backed off those 2 screws a bit and now I can set the lock off easily with my fingers. Those 2 screws were tightened down so much it was binding the lock up.

whetrock · « **Reply #24 on:** July 09, 2014, 09:40:46 PM »

hey James E.,
Acer opened a new thread in reply to your suggestion above. I hope the comments there are helpful.
Here's the link to that thread:
http://americanlongrifles.org/forum/index.php?topic=31560.0

Whet

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Author Topic: Dbl set trigger problem (Read 11589 times)

magyar

whetrock

whetrock

magyar

whetrock

whetrock

magyar

whetrock

jamesthomas

whetrock