Tips & Tools with Fred Stutzenberger – Part 12
This lock disassembly procedure has been provided by Mr. Keith Lisle. See custommuzzleloaders.com.
First thing is Safety for you and for the good of the lock. Never….. fire the lock without a flint or wooden piece the size of a flint in the jaw. Always have the frizzen closed when you fire the lock. The frizzen retards the forward motion & energy of the hammer (also called the cock) as the lock fires. Otherwise, the hammer hits the lockplate bolster & the tumbler hits the back of the bridle on the lockplate. The tumbler shaft takes all the energy and could fracture the tumbler shaft.
Also, don’t work on the lock with a flint in the jaws. It will cut you severely if it comes down on your finger. It will cut you to the bone!
Figure 1: REMOVE THE FLINT. Pull the hammer back to Half-cock. Put the mainspring vice on the spring so it is flush against the lockplate over the spring, slide it to the right to where top part of vice is up near spring part going up into the lockplate bolster. Turn thumbscrew left to open jaws as you slide it. When it is in position, barely tighten the thumbscrew about 1/8 turn on vice. Holding lock in Left hand, with right hand pull back on hammer slightly & pull up on Sear Arm to release the hammer & let the hammer gently down to fired position.Sometimes you have to go to full cock to get the main spring compressed enough to where it will come out with a spring vice, but on a lot of locks half-cock is enough. Some locks have a screw that holds the stationary leaf of the spring to the lockplate. The screw will have to be removed and placed in a secure place (such as a flat-bottomed bowl with a top) where it won’t get lost.
Figure 2. Notice the end of the Mainspring is off the Shoe of the tumbler now.
Figure 3: Now wiggle the vice & pull out as you wiggle the vice & the mainspring will come out. Put the mainspring in the bowl and leave it there.
Figure 4: Take a small screwdriver tip that Fits the spring screw that holds the Sear Arm Spring to the plate. Loosen that screw about 2 turns. Wiggle the spring & it will pop out of the retaining slot in the lockplate. Remove the screw & spring & put them in the bowl. Next, remove the Sear Arm screw & put it & sear arm in the bowl. Remove the Bridle screw & remove the bridle & screw & put them in the bowl.
You might be able to see that little movable lever that can be moved back and forth in the tumbler. That is the fly; if you are not careful, it will fly off to workshop never-never land, never to be found. Some locks are made with the flies on the plate side, some on the bridle side of the tumbler. Some flies have arms that they pivot on, others pivot on an arm integral to the tumbler. If on the bridle side, you can remove it with a magnetic screwdriver tip or simply lift it out with tweezers.
Wiggle & pull straight out on it to remove it; either tape it to the lid of the bowl or an index card with a hole to push the arm of the fly to secure it. The lock Will Not work properly without the fly installed correctly.
You have the Lockplate with Tumbler still sticking through it into the Hammer. The frizzen and frizzen spring spring still on. Under lockplate is the Fly. Under that is the mainspring with the vice on it. On right, you have the Sear Spring with screw, under it the Bridle with screw, under it the sear. (Sear arm is the right angle piece that sticks out towards you).
Figure 5: If you do not have a second spring vise, make a Frizzen Spring Tension Tool. Note: As Keith remembers it, he got his first such tool from Dave Motto (who may have designed that tool originally), at Friendship ~20 years ago. Since then, Keith made a couple of his own as one size does not fit all frizzen springs.
You can make it from a piece of mild steel rod or a large spike with a diameter about 1/4″ diameter. Heat it, bend it and file so it fits over the spring. My frizzen tool pushes up on the part the screw goes in to. So you squeeze it into the lock & it holds up on spring tip as you remove the screw, and you do same and align the screw holes & insert screw upon reassembly. Mount the tool as shown & turn it all the way over in your hand so the tool is on your palm, depress slightly as you remove the Frizzen Spring Screw See Figure 6.
Figure 6: When screw is out, remove the spring. Put the screw back into the spring. Put in bowl. Remove the Frizzen Screw from lockplate. Remove frizzen, put screw back through frizzen & put both in bowl.
Figure 6a: Now you have it all apart except the Hammer & the Tumbler. All the parts are laid out on the cardboard for viewing (you should have yours in the bowl).
Figure 7: Remove the tumbler screw that holds the hammer. Keith’s method is to put a rag over the vice jaw. Slide the lockplate over the edge of the vice so it is laying flat on the vice jaws, but has to be close to edge so as to not to elevate it on the bolster underneath the plate. Take a 1/4″ piece of brass rod & file it square on about 1/2″ of the end. Use a Brass Rod, Not steel. The tumbler shaft is very hard & brittle.
You go punching it with steel and it can shatter or break in the threaded hole. Rod needs to have a square end that will barely go inside the hammer square hole. (Not down in the tumbler shaft hole). Tap the tumbler shaft with a small hammer & brass punch and punch the tumbler out of the hammer. See Figure 8. The rag will catch the tumbler as in Figure 8. If you have access to a milling machine (or a friend who has one), you can make a little fixture as shown in Figure 9. Mine is made of scrap aluminum. You could make one from a piece of hardwood. It is very easy to use.
Keith cautions: DO NOT put a screwdriver under the hammer & try to pry the hammer off the shaft. If you do, it will fracture the shaft & you will be sending the lock back to Jim Chambers to have a new tumbler fitted & it is not a warranty item when you break it! They are Very fragile if abused.
Assembly is exact reverse of above procedure. When you put the frizzen spring back in, you squeeze the tool on the spring & align the hole & put in screw. When you put the sear arm spring on you snug it down close, press the spring & pop the retaining lug on the spring into the slot in the lockplate.
Thanks for all your help on this one, Keith.