Author Topic: Gap Between Cock and Lockplate  (Read 1527 times)

Offline Nhgrants

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Gap Between Cock and Lockplate
« on: December 17, 2019, 03:30:09 PM »
What is a reasonable gap between the cock and lock plate? Is 1/32" about what this should be?
With my L & R lock I have more gap than that.  I could file the tumbler to decrease the gap.
Also the gap is not even. I recall a post recently which discussed this unevenness.
Do you guys hand fit the cock to the tumbler to correct the unevenness?
Thanks 

Offline rich pierce

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Re: Gap Between Cock and Lockplate
« Reply #1 on: December 17, 2019, 03:45:30 PM »
The thing to look for is if the shoulder stop on the cock rests securely on the lockplate in the fired position. If there’s not enough testing there the cock could slip off.

Next, the cock has to clear any bridle screw stubs which typically extend a smidgeon past the lockplate.

Yes I adjust by filing. Sometimes a diamond file is needed. Sets of these are inexpensive on eBay. But the edges are not as sharp as regular files.
Andover, Vermont

Offline Eric Krewson

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Re: Gap Between Cock and Lockplate
« Reply #2 on: December 17, 2019, 05:21:36 PM »
I had an L&R with a huge gap, the cock stop just barely nicked the edge of the lock plate, I sent the lock back, they fixed one problem and created another.  Best to file it yourself.

Offline Scota4570

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Re: Gap Between Cock and Lockplate
« Reply #3 on: December 17, 2019, 08:08:33 PM »
I have one on the bench right now.  The hammer is tilted toward the center of the bore.  That makes it miss the nipple.   There is also a significant gap between it and the plate.  Fitting is would be much more straight foreword if the tumbler fit the plate properly, it is sloppy.  That means I have to reinstall the mainspring to see where I am at as I fit it. 

I once bushed the tumbler hole, in one of the mass market cast locks only to find out the tumbler bound up when assembled because the biridle screws were not properly located.   I gave up and hogged out the tumbler hole.   :(

Seems the time and tooling needed to tool up with jigs and reamers to do a good job would not be expensive.  Even using that cast parts would work if the holes were accurately drilled and reamed? Actually making the thing would only take a few minuets longer to do it right?

Offline rich pierce

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Re: Gap Between Cock and Lockplate
« Reply #4 on: December 17, 2019, 08:27:55 PM »
In another 10 years we won’t have these problems with locks made of cast parts, except for special builds where CNC’d locks are not available.
Andover, Vermont

Offline Bob Roller

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Re: Gap Between Cock and Lockplate
« Reply #5 on: December 18, 2019, 01:26:04 AM »
The thing to look for is if the shoulder stop on the cock rests securely on the lockplate in the fired position. If there’s not enough testing there the cock could slip off.

Next, the cock has to clear any bridle screw stubs which typically extend a smidgeon past the lockplate.

Yes I adjust by filing. Sometimes a diamond file is needed. Sets of these are inexpensive on eBay. But the edges are not as sharp as regular files.

Harbor Freight for reasons unknown to me have decent,useful Diamond
needle files for very little money.I have a set and so far they have been fine
for what little I do with them.
Bob Roller

Offline Scota4570

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Re: Gap Between Cock and Lockplate
« Reply #6 on: December 18, 2019, 04:54:41 AM »
I got the hammer straightened out on the lock mentioned earlier. 

"In another 10 years we won’t have these problems with locks made of cast parts, except for special builds where CNC’d locks are not available."

Good riddance!  On this lock, the sear nose is busted off .  It is a never used new lock.  I know they made knife edge sears on old locks.  But it it is a bad idea with cast parts.  Now I have to fabricate a new sear and probably a fly too.  The sear spring is orders of magnitude too strong and bears too far from the pivot.  I would gladly pay double for a decent lock. 
« Last Edit: December 18, 2019, 04:58:51 AM by Scota4570 »

Offline Jim Kibler

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Re: Gap Between Cock and Lockplate
« Reply #7 on: December 18, 2019, 06:23:25 PM »
I have one on the bench right now.  The hammer is tilted toward the center of the bore.  That makes it miss the nipple.   There is also a significant gap between it and the plate.  Fitting is would be much more straight foreword if the tumbler fit the plate properly, it is sloppy.  That means I have to reinstall the mainspring to see where I am at as I fit it. 

I once bushed the tumbler hole, in one of the mass market cast locks only to find out the tumbler bound up when assembled because the biridle screws were not properly located.   I gave up and hogged out the tumbler hole.   :(

Seems the time and tooling needed to tool up with jigs and reamers to do a good job would not be expensive.  Even using that cast parts would work if the holes were accurately drilled and reamed? Actually making the thing would only take a few minuets longer to do it right?

Scott,

I think your're absolutely right.  Even with castings and manual machines there is no reason better could have been or be done better.  I think all this stems from the nature of muzzleloaders and the view many have.  A little rough around the edges is ok...  I'm sure most lock assemblers don't have a milling machine.  It's done largely with belt grinders, drill presses, drill jigs etc.  Even with manual machines things could be done so much better.  A DRO and a milling machine would improve quality imensely.  You might say it would slow things down.  This might be somewhat true, but manual machines are cheap now days.  A machine could be set up and dedicated for particular operations.  For example, plates could be milled flat, not belt sanded.  Holes could could be drilled on another etc.  The concept of cottage industry lock assemblers wouldn't work with this approach however.  I think this model worked for years, but has serious shortcomings.

Jim

Offline EC121

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Re: Gap Between Cock and Lockplate
« Reply #8 on: December 18, 2019, 11:14:27 PM »
Just for the sake of discussion.  Lock assemblers receive in the neighborhood of $40 per lock for the assembly.  If the lock works at all, you are probably getting your $40 worth.  To paraphrase the drag racers: Precision(Speed) costs money.  How precise(fast) do you want go?  ;)  ;)   Buy a kit and see if you would do it for $40.

    CNC will help in the precision category, but then you run into machine time that also costs money.  Economy of scale will help some, but higher costs will still be there for a well built lock.
Brice Stultz

Offline Jim Kibler

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Re: Gap Between Cock and Lockplate
« Reply #9 on: December 18, 2019, 11:40:52 PM »
Just for the sake of discussion.  Lock assemblers receive in the neighborhood of $40 per lock for the assembly.  If the lock works at all, you are probably getting your $40 worth.  To paraphrase the drag racers: Precision(Speed) costs money.  How precise(fast) do you want go?  ;)  ;)   Buy a kit and see if you would do it for $40.

    CNC will help in the precision category, but then you run into machine time that also costs money.  Economy of scale will help some, but higher costs will still be there for a well built lock.

Better doesn't always mean harder or more costly.  As soon as someone accepts the premise that "you're lucky things are as good as they are" or "we're doing all we can for what we get out of this" you shut down progress.  In a way it's a cop-out.  We've shown on our kits there is a huge appetite for better even with a slight cost premium.  Locks are difficult, but we're working everyday to make things better and faster.

Jim

Offline Scota4570

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Re: Gap Between Cock and Lockplate
« Reply #10 on: December 19, 2019, 12:02:12 AM »
The lock is not worth much if the sear nose crumbles before the first shot. 

I get the feeling that on some of my locks the cast in dimples were used to locate the drill bit.  I would also guess that  drilling the holes in one step (drill bits love to cut over-sized) would account for the sloppy threads.  I also get locks with warped plates and a long list of other issues.  They are a lot like working from a precarve, 90% inletted kit where I spend more time messing around with built in errors that it takes to start from scratch.   Like I said before , I would pay double for a quality lock, say $300+.  Avoiding the  frustration and disappointment would be worth the cost to me. 

Since I do not have the drill jigs, reamers, and other specialized tools it takes me much longer to assemble a lock that the $40 would justify.  I only see about 1/2 hour in the some of the locks I have had to rework assuming  are using jigs and are tooled up to do the one thing.  If they are using cast in dimples to locate screw holes and drilling the tumbler hole, that might explain why it only costs $40.   

Offline Bob Roller

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Re: Gap Between Cock and Lockplate
« Reply #11 on: December 19, 2019, 12:28:52 AM »
$40 to assemble a lock?Not from my shop but then I am no longer making locks.
My methods ranked right up there with the stone axe but I did achieve a decent
level of quality control.I think the CNC methods will become predominant and the
quality will be high as long as springs are up to the job.
A more affluent market can and will pay more for quality locks.In the 60's and 70's
and even into the late 80's the lock had to be cheap along with all else to do with a
muzzle loader but I think that bunch is mostly gone now.

Bob Roller

Offline John Shaw

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Re: Gap Between Cock and Lockplate
« Reply #12 on: December 19, 2019, 04:18:04 AM »
This thread sure makes me thankful for the J.D. Dougall lock I put on my 32 many years ago. I got it for not much money since someone had managed to break off a piece of the tumbler somehow. It didn't effect the function and the lock is a precision piece of work done when things were a whole lot different than they are now. We are lucky to have a few people around like Jim Kibler who are striving to produce quality work for those who don't mind paying a little more to get the best.

JS