S&W Model 1 - Latch Configuration/Cylinder Stop

[gobsauce]

I feel like there was some reason for this odd design.

As an engineer, it makes no sense. However, how long does a firearm take to go from the design board to manufacturing?

I think it's possible that the iron was designed before the patents were expired, and could have been manufactured late for XYZ reason.

But what do I know.

 

[Johnm1]

From a previous post of mine:

I'll smoke the latch to see where the conflict is. But it'll have to wait until after the Suns game.

As it turned out the locking surfaces of the latch were fine. Smoking showed it was one of the side surfaces of the latch that conflicted with the frame. Held in the hand the latch fit around and into the frame. But when installed in the barrel one side of the latch conflicted with the frame. This leads me to believe that the latch was a replacement and was never fitted correctly. Judicious polishing one side of the latch itself allowed the latch to function. This is a stock photo grabbed from the internet.


Without the spring I only fitted the latch to the frame until it just went in and that took a little force. More force than what I would have thought a spring would be able to provide. But I wanted to wait until the spring arrived before final fitting so I wouldn't 'Over Fit' the latch. I wasn't sure how much impact the spring would have on the final fitting. And I'm glad i waited because once I had a spring that worked I didn't have to fit the latch further. Proof that sometimes doing nothing is better than doing something.

For the actual Gunsmiths here. Is 'Over Fitting' an actual thing in the trade and is it something discussed in Gunsmith school?

 

[beag_nut]

I don't know how much "smoking" you do in regards to machinery, but a much simpler method is Dykem Steel Blue layout fluid. Used by machinists world-wide, as the go-to for marking mating surfaces. Just suggesting. Another option is Permatex, also no flame required.

 

[Johnm1]

I don't know how much "smoking" you do in regards to machinery, but a much simpler method is Dykem Steel Blue layout fluid. Used by machinists world-wide, as the go-to for marking mating surfaces. Just suggesting. Another option is Permatex, also no flame required.

I bought the oil lamp when I was fitting a stock on a Winchester 1905 because that was what was available the day I wanted to start that work and I've just continued with it. It works.

 

[Jackrabbit1957]

I used Dykem in the past, then it got expensive. I too use a kerosene lamp and smoke, also use a sharpie marker quite a bit.

 

[gobsauce]

I don't know how much "smoking" you do in regards to machinery, but a much simpler method is Dykem Steel Blue layout fluid. Used by machinists world-wide, as the go-to for marking mating surfaces. Just suggesting. Another option is Permatex, also no flame required.

It works the same way. Smoking was used before things like Dykem was available. I think Larry Potterfield has a few gunsmithing videos where he uses both.

 

[Johnm1]

I wanted to wait until the spring arrived before final fitting so I wouldn't 'Over Fit' the latch. I wasn't sure how much impact the spring would have on the final fitting. And I'm glad i waited because once I had a spring that worked I didn't have to fit the latch further. Proof that sometimes doing nothing is better than doing something.

For the actual Gunsmiths here. Is 'Over Fitting' an actual thing in the trade and is it something discussed in Gunsmith school?

That is a real question. Do professional gunsmiths consider only fitting a part until it just fits and no more? Is this a subject in gunsmithing school? Or is it a part by part decision?

I often rough fit parts with a minimum of reassembly. An example would be a hammer. I might put it on its pivot pin but to check dimensions while I'm 'rough sizing' the part. But when I get close to the final shape I'd install the mainspring to check the final fitting of the part in its final configuration.

 

[Jackrabbit1957]

My thoughts are make the part oversize and fit it slowly with lots of checking fit. You can always take a little off, harder to put it back if you goof. I don't remember if they discussed it in the gunsmith scholl I went to, only been a 110 years ago.

 

[Johnm1]

Hinge on hammer? I assume you mean the cylinder stop hand which is mounted on top.

Actually no. The first issue had a different hammer. I can't find a picture

Not a picture but a diagram. This is a depiction of the first issue hammer. This changed relatively early in the production run.

 

[Johnm1]

Parts arrived today. This is the first time Jack First has let me down.

We all know that things happen. It is what we do after something happens that makes the difference. In this case Jack First responded very well. The replacement spring is on its way. They even took the time to take their example firearm apart to verify before sending the replacement.

I purchased a second cylinder latch spring so I could experiment bending it a little further. I asked a question about the spring because the first one I received didn't have the amount of "springyness" (another technical term) I expected. It was very stiff when I bent into shape and it does work. Even though it was just a question they took the time to analyze their springs and even heat treated the second spring before sending it.

Things happen. It's how we respond that's important. Some company's get it. Jack First certainly does.

 

[Johnm1]

Parts arrived on Friday. The latch spring was a perfect fit. It is much stiffer than the spring I made. I'm hoping it will loosen up over time as it is qquite stiff to open.

I also bought another cylinder stop spring so I could experiment bending one more and not risk breaking the only one I had. I'm glad I did as I broke one in the process. I did manage to bend the original spring a little further and the result is a little better. The cylinder stop is pushed down a little harder and engages the stop notches better. So now when the hammer is forward the cylinder doesn't freewheel. At least on 4 of the 7 cylinders. I don't see how I could improve upon the leaf spring pressure without breaking the spring. I could experiment with a piano wire spring I suppose.

 

[Johnm1]

Further testing shows that now the cylinder does stay locked as the hammer passes under thee cylinder stop on the way forward on all 7 chambers. I thought the split spring on the bottom of the cylinder stop was supposed to allow the hammer 'bump' to split the spring on its travel forward thus not raising the cylinder stop as the hammer traveled forward. When the hammer is pulled back there is a ramp on that side of the split spring that forces the hammer bump to push up the cylinder stop up to allow the cylinder to rotate freely. Here is a picture of the cylinder stop split spring. In this picture the spring is upside down



Here is how the split spring is arranged. In this diagram the split spring is rotated 90 degrees from how it is installed. It is part #11.



In the above diagram part #9 provides the spring action to drive the cylinder stop down and engage the stop notches. This is the spring I had to bend to apply the correct amount of force on the cylinder stop.

Here is a side view of the arrangement. The green is the split spring.

 

[Johnm1]

Here is a short video of the cylinder stop function. As the hammer is drawn back the hump on top of the hammer pushes the cylinder stop up. Notice how high it rises. Before releasing the hammer I put pressure on the cylinder in the direction of rotation. Notice how the cylinder now doesn't unlock/rotate as the hammer passes under the cylinder stop. Although the cylinder stop rises it doesn't rise enough to unlock the cylinder stop from the stop notches.

https://photos.app.goo.gl/unYgtEnzAMGbQZEfA

In my case, the cylinder stop split spring is missing one leg. It works well enough but I suspect it would work better if it were all there. Allowing the hammer hump to cleanly pass between the split legs of the spring and not causing the cylinder stop to rise at all.

Edit to add: All of the functions of the cylinder stop can be overcome by applying enough rotational force to the cylinder. The cylinder notches do have 150 years of wear, so it isn't something I'm concerned with or would consider addressing.

 

[Johnm1]

I picked this quote from a post Driftwood Johnson wrote in this thread

https://www.thehighroad.org/index.php?threads/s-w-1-1-2-old-fuff.798126/

"You are correct about the function of the part. The spring snugs the cylinder stop down. When the hammer is cocked, the rear of the bump on top of the hammer raises the spring, raising the cylinder stop. When the hammer falls, the wedge shaped front of the bump splits the spring open, so the cylinder stop stays down and engaged. I cannot offer any advice about where to find a new spring, usually collectors buy junkers to cannibalize for parts, and unfortunately this spring is often broken on junkers.

So it seems mine is not perfect. I'll search for a split spring but for now it's close enough.

 

[Johnm1]

Gah I need to see you shoot it!

This one's for you Gob

I tried several things today. Cut off Colibri's, eh. Flobert, eh. And a scatter brained idea. I pulled the ball from 21 Flobert rounds, filled the space with 4F (about 1.5 grains by weight) an glued the ball back on top! I chickened out on the glue though. I wasn't sure what would happen if a ball came loose under recoil so I filled each chamber with black powder lube to hold an errant ball in place. Here are the results.

https://photos.app.goo.gl/Rgz4oEmqbvuESQy47

A close up of the target



Ok, so it was only about 10 feet. EDIT TO ADD: Well maybe closer to 5 feet.

 

[gobsauce]

This one's for you Gob

I tried several things today. Cut off Colibri's, eh. Flobert, eh. And a scatter brained idea. I pulled the ball from 21 Flobert rounds, filled the space with 4F (about 1.5 grains by weight) an glued the ball back on top! I chickened out on the glue though. I wasn't sure what would happen if a ball came loose under recoil so I filled each chamber with black powder lube to hold an errant ball in place. Here are the results.

https://photos.app.goo.gl/Rgz4oEmqbvuESQy47

A close up of the target

View attachment 1078580

Ok, so it was only about 10 feet.

YES YOU DID IT! LETS GO!

That actually has more recoil than I anticipated. Expected it to have almost nothing.

Question, is this meant to be carried with the hammer on an empty chamber?

 

[Johnm1]

S&W instructed it to be carried with the hammer in between cartridges. And that does work.

The Flobert and Colibri's were let's say anticlimactic. I uploaded the second cylinder to the same folder.

 

[Johnm1]

According to the below article Smith and Wesson offered this explanation

https://sportsmansvintagepress.com/read-free/smith-wesson-hand-guns/smith-wesson-tip-up-revolvers/

half-cock or safety notch was provided, the manufacturers excusing the omission in the following words included in the directions for loading:

“A half bent is entirely dispensed with, as it is found to be much more convenient and safe to carry the hammer resting between two of the cartridges; when so placed it is impossible to be accidentally discharged.”

 

[gobsauce]

According to the below article Smith and Wesson offered this explanation

https://sportsmansvintagepress.com/read-free/smith-wesson-hand-guns/smith-wesson-tip-up-revolvers/

half-cock or safety notch was provided, the manufacturers excusing the omission in the following words included in the directions for loading:

“A half bent is entirely dispensed with, as it is found to be much more convenient and safe to carry the hammer resting between two of the cartridges; when so placed it is impossible to be accidentally discharged.”

So if I understand correctly, they believed that a half cock safety would fail?

 

[Johnm1]

So if I understand correctly, they believed that a half cock safety would fail?

I read it to mean they thought it unnecessary. The fact it saved a little cost was just a fortunate byproduct.

 

[Johnm1]

I'm making plans to fabricate a new split spring to replace the one in the firearm. The one thats there works but one ear of it is broken off and makes its function 'soft' at best.

In this closed post Old Fuff provided a detailed drawing and some instructions on how to make the same spring for a 1 1/2. The dimensions won't be the same but the materials and methods will be. Plus most of my spring is still there. What is missing exists on the other side. So I have enough left to determine all of the dimensions.

https://www.thehighroad.org/index.php?threads/s-w-1-1-2-old-fuff.798126/

Thanks Old Fuff! Your knowledge lives on

 

[Johnm1]

I spent the day trying to fabricate a new split spring. Wrong material and the wrong tools made it a waste of time. I'm trying to correct a perceived issue that as the hammer travels forward it unlocks the cylinder just before ignition. With the firearm empty the nub on the hammer pushes the cylinder lock up before the hammer has finished its forward movement.

My split spring has one of its legs broken off and I've assumed this was the cause of the percieved issue. It was hard but I took the time to observe the cylinder stop in action and the leg that does exist functions as it should and moves out of the way of the hammer. Yet the cylinder does unlock before the hammer finishes its forward motion.

So what is worn? Turns out nothing is worn and the cylinder does stay locked all the way through ignition. The key is having ammunition in the cylinder. The firing pin strikes the cartridge before the hammer has traveled all the way forward. The cartridge holds the hammer back far enough that the nub on top of the hammer hasn't reached the cylinder stop to lift it and unlock the cylinder.

I just tested this theory using expended cartridges. While applying significant rotational force on the cylinder I pulled the trigger and the cylinder would not turn. The cylinder has great lock up with the hammer back and maintains that solid lock up all the way through ignition.

So I don't have to replace the split spring. I'll continue to try to make one as these springs were a known weak point and failed often.

Now with no cartridges in the cylinder, the cylinder wants to freewheel. And I'm not sure that wasn't how it was designed. With the cylinder loaded the firearm has to be carried with the hammer resting between cartridges as the hammer at rest will be in contact with the cartridge. And the configuration of the cylinder stop/hammer has the cylinder stop being raised by the hammer with the hammer all the way forward and no cartridges installed.