Frizzenspring
The frizzen springs were made from an old truck leaf spring, 12mm thick
(about 1/2inch). First step is to hack saw out a rough blank about 13cm x 2,2 cm. The blank is annealed by heating in a heat-treating oven at 800 Celsius for 30 minutes and buried in a bucket of pearlite overnight. Since the blank is oversized, loss of material from scaling does not matter.
This blank is then milled to a rectangle 120mm x 19mm x 8mm and the leaf rough milled out 3,2mm thick and 90mm long.
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Mark out the width of the leaf and the placement of the spring peg. Drill, saw out and mill to correct dimensions.
I then made a hollow mill for the peg from 10mm round stock silver steel. I center drilled a 2,5mm through a 30mm piece round stock, filed the teeth then drilled a 4mm hole from the rear, almost all the way through. Heat bright orange with an acetylene/oxy torch and quench in cold water.
If you don’t relieve the inside of the mill, there is a tendency for the peg will stick and twist off, no matter how much cutting oil is used. I did this mistake on my first attempt to make a hollow mill.
To center the peg blank, use a 2,5mm drill in a drill chuck mounted in the mill. Replace the chuck with the hollow mill in a 10mm collet. Mill out the peg using plenty of cutting oil.
Next make the jig for locating the frizzen screw hole. Take a strip of brass the same width as the final blank end(8mm). Mark a center line. Drill a 2,5mm hole for the peg, drill a hole the correct distance for the frizzen screw. Glue to the blank. Drill the hole for the frizzen screw(3mm). Notice the frizzen end is kept way to long. This is so it can be held steady in the vice for milling and drilling.
Make a template for the frizzen final. It’s basically a 3M screw with a 6mm head and a 6mm round «nut». Mount it in the frizzen spring screw hole.
Mill away as much as possible of excess metal.
Use a pillar file to file the screw cylinder round. Make a simple jig to hold the spring blank at an angel for milling the taper.
File out the tail of the final. Heat the bend location with the smallest oxy/acetylene torch and bend. Heat bright orange, quench in clean cold water. I tried using oil, but that gave a mushy spring with this steel. The spring was then annealed in an oven at 370 Celsius for 30minutes. The spring works great.
Picture of the unbent spring on a rough blank, shows the amount of steel removed. Finished spring mounted on the lock.
Main springThe main spring was made from 3mm (1/8 inch) thick 1095 spring stock from Brownell. Won’t be buying that stuff again. The stock was rock hard, especially the edges which must have been work harden. The lengths were 16 inch long. Way to long for annealing with an acetyl/oxy torch. To cut it with a hacksaw, you grind through 1/6 inch of the edge with a Dremel before you could saw it.
I followed the booklet «Simplified v-springs» by Kit Ravenshear in making the spring. Cut off a suitable length of steel, marked off the placement of the peg and eye hole with a brass pattern.
Next I heated and twisted the eye tab, heated to annealing temp and buried it in pearlite to cool overnight. Next day, I drilled, sawed and milled out the peg. The peg was milled rounded with the same hollow mill used on the frizzen spring.
Glue the brass pattern to the blank, drill out the screw hole. File out the eye and the outer profile of the blank.
I used the same jig to mill and taper the main spring and frizzen spring. First i mounted it horisontal in the vice to reduce the thickness of the hook end to 2mm, then mounted slanted to mill out the taperd portion of the lower leg.
The same jig Is great to hold the spring for draw filing and polishing.
The springs where bend using an oxy/acetylene torch, following Ravenshear’s booklet. I’m not to happy with his methods. Two main problems.
1. Twisting the tab for the screw eye creates a “threaded” neck between the eye and the short leg. See the nick on the left side of the underside of neck in the picture to the right. There is a similar nick on the right side of the topside of the neck. This weakness made the neck break when I reduced the thickness of the eye to 1/16 inch, no matter how careful annealing. The only solution was to leave it 1/8inch thick.
2. Lack of repeatability when bending without jigs and fixtures. Even though the spring blanks were identical, and the bends marked out the same the placement of the main bend and the start of the hook varied +-3/32 inch. This could interfere with the placement of the front lock nail and cause the hook to jam or fall of the tumbler.
Think I would prefer to use thicker spring stock and mill/ file out the eye and the hook. If you look at the pictures of the finished locks, you’ll see the main bend is U shaped not a sharp V shape. I tried a sharp V on the first spring. Did not work. The sharp V placed the long leg to high up on the plate. When trying to set the lock on full cock, the spring jammed on the mainspring screw. Not enough room to move. The U bend lowers the leg on the plate and gives it ample room to move.
Both locks work fine. Whats left to do is final clean up an polishing before case hardening. Don’t know when I’ll have time for this. No more vacation time and I have to make crucbles and do test runs before try it on the locks. Never pack harden before.
The next and last chapter will be Pack hardening the locks. Here are links to the parts done sofar:
Part one, the lockplate.
http://americanlongrifles.org/forum/index.php?topic=49769.0Part two, the cock.
http://americanlongrifles.org/forum/index.php?topic=49838.0Part three, the pan.
http://americanlongrifles.org/forum/index.php?topic=50191.0Part four, the frizzen.
http://americanlongrifles.org/forum/index.php?topic=51056.msg506885#msg506885Part five, the tumbler, bridel and sear.
http://americanlongrifles.org/forum/index.php?topic=52824.msg527631#msg527631Best regards
Rolf
