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General discussion => Gun Building => Topic started by: Ats5331 on November 01, 2021, 12:50:51 AM

Title: Lock Issues
Post by: Ats5331 on November 01, 2021, 12:50:51 AM
Hi all,

Tinkering with my chambers deluxe flintlock I was using at Mike Brooks class.

The lock was functioning perfectly in class, however, now that I am home, I have noticed that the lock is not engaging at full cock.

I took it apart and inspected all the parts, it seems to look alright to me? When the mainspring isn’t on, I hear the two clicks and the fly catches at full cock. When I install the main spring, it doesn’t catch at full cock..

Any thoughts?

Title: Re: Lock Issues
Post by: smart dog on November 01, 2021, 12:52:32 AM
Hi,
Back off the tension on the sear screw a tiny bit to see if that solves the problem.

dave
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 12:56:00 AM
Hi Dave,

I’ve attempted that several times, it doesn’t seem to be working however?

I know it’s hard to explain via typing..

Thanks,
Allen
Title: Re: Lock Issues
Post by: rich pierce on November 01, 2021, 01:12:15 AM
Are you able to pull the cock back far enough to make the fly fly forward when the mainspring is in place? Sounds like that may be it.
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 01:20:20 AM
@Rich

Yes, I am able to do that, but it doesn’t want to catch at full cock when assembled…

Puzzling
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 01:24:56 AM

(https://i.ibb.co/dcDwJhR/image.jpg) (https://ibb.co/3sc9YJn)


The fly moves forward but it’s is not catching to allow the cock to rest at full cock. I tried to get a picture to show the issue
Title: Re: Lock Issues
Post by: Stoner creek on November 01, 2021, 01:35:32 AM
Screws in the bridle are too tight. Back the sear screw off one half turn.
Title: Re: Lock Issues
Post by: Bob Roller on November 01, 2021, 01:54:39 AM
Is POSSIBLE that mainspring is touching the bolster on the lock plate. I got rid of that style of mechanism in 1970 and never used it again.I would think that a bridle binding the tumbler would interfere with the half cock as well.Take a small hone and polish the tip of the sear and the polish the intercepting side of the fly that engages and pushes the sear out of half cock on the way down.
Bob Roller
Title: Re: Lock Issues
Post by: rich pierce on November 01, 2021, 02:01:43 AM
Bingo it looks like the hook of the mainspring is touching the bolster. Whether that is the issue or not, it shouldn’t be happening.
Title: Re: Lock Issues
Post by: D. Taylor Sapergia on November 01, 2021, 02:08:25 AM
Your photo is great, except that the only part that is important is too dark to see what's going on there.  Try again with light playing on the tumbler notches, please.  To allow the tumbler to rotate a little further, if that is required, file the spot on the plate's bolster to remove metal, allowing the mainspring to come up a few more thou.
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 02:21:56 AM
Here’s a picture in better lighting. I have another lock and am comparing functions. The main spring doesn’t touch on either of them. To me, it looks like the bridle isn’t catching on the tumbler (my terminology may be off here).

(https://i.ibb.co/rMmCzwH/A6-C264-DB-BBF5-45-CC-91-C6-76-C2-FFD2-C736.jpg) (https://ibb.co/820Wf79)

(https://i.ibb.co/28zxYnS/CBD74-DA1-C3-C2-44-FB-BECB-FC31-EC3-A6-CFB.jpg) (https://ibb.co/M8zr52f)
Title: Re: Lock Issues
Post by: Scott Bumpus on November 01, 2021, 03:25:35 AM
Is the tit on the front of the main spring seated fully in the lock plate
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 03:28:46 AM
Yeah, it’s on completely. I took the main spring off and the fly/catch system works perfectly? This leads me to believe the mainspring is a culprit
Title: Re: Lock Issues
Post by: Scott Bumpus on November 01, 2021, 03:37:54 AM
That is a replacement fly and may need a little fitting.
Title: Re: Lock Issues
Post by: Frozen Run on November 01, 2021, 03:43:25 AM
This leads me to believe the mainspring is a culprit

Occam's Razor, if the lock functioned perfectly throughout the class, it's likely a home shop error in reassembly or maybe a tenacious wood chip that slipped out the mortise and is jamming it up somewhere. Is the lock seizing up in the mortise or out of it? I'd sleep on it, and get some professional in person supervision before modifying a lock.
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 03:55:32 AM
Yeah, Don. I haven’t tinkered with it at all or modified it. I feel like it’s the mainspring or a fly issue..I’ll have a friend give it a look over.

At this point I have spent too much time trying to figure out what’s wrong.
Title: Re: Lock Issues
Post by: Bob Roller on November 01, 2021, 02:33:03 PM
I doubt if a non functional lock would get out of Jim's shop any more than one would from mine.
Bob Roller
Title: Re: Lock Issues
Post by: Scota4570 on November 01, 2021, 05:11:16 PM
A better view:

(https://i.ibb.co/jMPPmGc/CBD74-DA1-C3-C2-44-FB-BECB-FC31-EC3-A6-CFBA.jpg) (https://ibb.co/85LLq2W)
Title: Re: Lock Issues
Post by: PAFlinter on November 01, 2021, 06:47:43 PM
Is it me or are your screws not screwed in completely.  That could be "cocking" things just enough
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 07:03:39 PM
Wayne gave me some advice to back off the screws, I tried back some off, tightening others, etc. to no prevail.

Might call Barbie and see if she has some advice
Title: Re: Lock Issues
Post by: PAFlinter on November 01, 2021, 07:11:53 PM
silly question.  do you have the screws in the right locations.....is one screw hitting the cock perhaps?
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 08:00:24 PM
Yeah, I checked that over as well. Barbie thinks it may be a tumbler problem, so we may try a new tumbler on it.

This one was a stumper!
Title: Re: Lock Issues
Post by: D. Taylor Sapergia on November 01, 2021, 08:36:20 PM
In your last phot, it appears to me that the sear nose is way up past the full cock notch...what's up with that?  Why are you pulling the hammer back so far that the sear nose passes the full cock notch up into the tumbler?
Title: Re: Lock Issues
Post by: Ats5331 on November 01, 2021, 08:43:44 PM
In your last phot, it appears to me that the sear nose is way up past the full cock notch...what's up with that?  Why are you pulling the hammer back so far that the sear nose passes the full cock notch up into the tumbler?

Taylor, I was pulling it to where it should catch at full cock. Since it doesn’t currently catch, I was holding it with my thumb to try to take a picture, so that may be way it looks odd. As I said in my previous post, I chatted with Barbie and she believes the tumbler notch may be bad. Sending me a new tumbler this week
Title: Re: Lock Issues
Post by: Clark Badgett on November 02, 2021, 12:28:25 AM
Both screws look to be 2-3 turns backed off. Screw them down flush and then lightly back them off, like maybe an 1/8th of a turn.
Title: Re: Lock Issues
Post by: kutter on November 02, 2021, 02:05:27 AM
The tumbler looks 'canted' in it's position under the bridle and up against the back of the lock plate.
The rear edge of the tumble where the sear edges are located is up off of the plate surface a small amt.
The front arm or hook that engages the mainspring is down onto and scraping the lock plate surface.
There is a scar mark in the plate from it's movement. I assume the scar has been worn there only when the mainspring pressure has been in play/ in place.

Either bridle needs to be fitted better to hold the tunmbler down more squarely onto the plate,,something you can't always easily accomplish given the as cast qualities of parts and the dimention of the already drilled and reamed holes it runs on.
But the engagement of that arm of the tumbler may itself be at a slight angle and not square withnthe mainspring hook. Or the spring hook itself may be finished at an angle as well. either or both together when engaged with the powerful spring tension imposed onto the tumbler can push the entire tumbler one way or the other if the pivot holes and axels are not fitted well.
In this case I think the tumbler is being pushes in towards the lock plate at the juncture of the mainspring hook and the tumbler arm.
 As the lock is cocked the rotational motion of the tumbler may be being stalled just before the sear can drop into the full cock notch as that arm digs into the lock plate.

Remove the mainspring and everything works fine w/ lots of play in the parts and the arm of the tumbler free to slide above the plate surface.


I'd examine that carefully and if a problem I'd file some relief to the back edge of the end of the arm of the tumbler and remove any sharp edges around the part(s).

Check the plate with the mainspring removed also and make sure the spring,especially the hook, isn't doing the same thing of scraping against the plate especially at it's high point of compression.
The lock plates are often unevenly polished 'flat' and especially under the edge of the bolster there may be a slight high spot that the spring can run into and stall as well.
Title: Re: Lock Issues
Post by: Willbarq on November 02, 2021, 08:09:07 AM
Did you have the Cock off the tumbler? ya know the square hole ........ you got it one position off I bet.
Title: Re: Lock Issues
Post by: Daryl on November 02, 2021, 06:59:23 PM
Did you have the Cock off the tumbler? ya know the square hole ........ you got it one position off I bet.

You made a good point, Willbarg. On chamber's locks, the cock should be further back at full bent postion.
Title: Re: Lock Issues
Post by: Willbarq on November 02, 2021, 11:06:58 PM
When you put the cock back on , it will seem like it's too far forward towards the frizzen. There is still a  tension on the mainspring even with the lock "at rest position"  Watch your fingers....don't make ouchy.