Lock Improvement

[Jim Kibler]

A couple days ago, a customer and ALR member (Thanks Dave) recently purchased one of our new locks.  He was very complimentary, but offered one small critique.  The contact between the cock stop and the plate was at a slight angle.  That is, the surfaces weren't parallel.  I'd noticed this, but didn't think it to be very significant.  After looking more carefully, however, some locks had more of an angle than others due to casting variations.  So, we are now machining this surface by locating off of the tumbler hole in the cock.  You can see the before and after photos.  As mentioned, I don't think the issue is cause for any great alarm, but we're just trying to make a more perfect product.  Machining this will also alow us to have a tumbler stop on the sear spring screw as well.  Currently we have clearance at this point, but machining the cock shoulder will allow for both stops.  I think I will make the plate contact occur just a touch before the tumbler / screw.  Thanks again, Dave.

All the best,
Jim

[Daryl]

I like to see the flint's cutting edge at that height above the pan, Jim.  If lower into the pan like on some of my locks
the flame from the vent burns the flint's cutting edge into a rounded corner that sweeps across that cutting edge from
barrel side to the other.

[hanshi]

I like to see the flint's cutting edge at that height above the pan, Jim.  If lower into the pan like on some of my locks
the flame from the vent burns the flint's cutting edge into a rounded corner that sweeps across that cutting edge from
barrel side to the other.

I'm not the only one to get that flint edge erosion then.  Some of my locks are more likely to do that than others.

[rich pierce]

Lots of originals got worn where the cock battered the top edge of the plate. Welding or brazing some steel on the shoulder of the cock is an option. It takes very little.

[smart dog]

Hi Jim,
Thank you very much for this post.  It shows your commitment to quality. I am sure cast parts are a nightmare for precision. Surely, there are foundries working for the Defense establishment that produce incredibly precise products, but they don't work for us. Hopefully, when you correct the geometry it does not result in the back of the tumbler hitting the bridle with too much force. As you know, a lock is a system in which one change in a part can lead to a series of changes in other parts. Again, thank you Jim and I am sure you and Chris Laubach are leading the way to the future.

dave

[davec2]

Jim,

Thanks for the update.  When I made mention to you of the very minor issue of the cock shoulder / plate parallelism (less that 48 hours ago) I had no idea you would jump on a fix so fast !  Thanks so much for a great product at a great price and for your continuing commitment to quality and improvement.

Dave Crisalli

[Jim Kibler]

Thanks guys.  No problem with the tumbler and sear screw contact after cutting this down.  There's plenty of clearance.  The great part about machining these parts is that it can easily be adjusted if necessary.  Not like dealing with cast parts and molds. 

As far as tolerances go with castings, it's a process that's inherently less precise than machining.  Probably by at least a factor of 10.  That's one really good thing about machining.  It's a process that can create parts well beyond the dimensional requirements of lock parts.  This means you're not pushing a process to the limits and makes producing a high quality product much easier.

All the best,
Jim

[Frank]

A couple days ago, a customer and ALR member (Thanks Dave) recently purchased one of our new locks.  He was very complimentary, but offered one small critique.  The contact between the cock stop and the plate was at a slight angle.  That is, the surfaces weren't parallel.  I'd noticed this, but didn't think it to be very significant.  After looking more carefully, however, some locks had more of an angle than others due to casting variations.  So, we are now machining this surface by locating off of the tumbler hole in the cock.  You can see the before and after photos.  As mentioned, I don't think the issue is cause for any great alarm, but we're just trying to make a more perfect product.  Machining this will also alow us to have a tumbler stop on the sear spring screw as well.  Currently we have clearance at this point, but machining the cock shoulder will allow for both stops.  I think I will make the plate contact occur just a touch before the tumbler / screw.  Thanks again, Dave.

All the best,
Jim

My lock looks like the top photograph. Will this affect the long term durability and reliability?

[Jim Kibler]

Frank,

It's not a big deal.  On the ones I've looked at, the contact point was actually not right on the back edge of the cock stop, but rather inside by a bit, so I don't think you'll get any deformation.  You can fix it by just filing this a touch if you would like.  You can also just pop it in the mail to us and we'll adjust it and send it right back.

All the best,
Jim

[smart dog]

Hi Jim,
Thanks for responding to Frank's question.  I suspected that a few swipes of a file to remove metal from the back edge of the shoulder would be all that was needed. I've had locks from Chambers and others that had the same issue. My only concern was that the tumbler and bridle had enough room to allow the cock to rotate a slight bit forward as it will when the shoulder is filed.  Your previous post answered that question.

dave

[Frank]

Thanks for the quick response Jim. Seems like an easy fix.