Each frizzen starts as a chunk of mild steel 75mm x 55mm x 30mm. The pictures below show the original frizzen on top of a blank.
The first step is to make the brass patterns. Mill out a stepped piece of hardwood and glue on 1/16 brass sheet. Use drill hole to fix the frizzen to the block. Scribe around the frizzen toe, underside of the pan cover and the striking side of the frizzen, but not the top of the pan cover or the front of the frizzen.
Cover the front of the frizzen and the top of the pan cover with masking tape. Mark off increments and measure the maximum thickness at these points. Transfer these points to the brass and saw out the patterns.
Mill the frizzen blank completely square and then mill out the part for the frizzen toe and glue on the patterns. Make sure the bottom of the pan is square to the side of the blank. Paint with dykem, scribe round, drill out the hole for the frizzen screw, heat remove patterns.
Drill out the blank with a 2mm drill. Getting a 2mm drill through 30mm steel is the most tedious part of the process. Next saw out the bottom of the pan cover.
Mill out the bottom of the pan cover. Since the top and bottom of the blank is square, mounting the vice is simple. Next saw out the rear face of the frizzen.
Clean up the striking surface with a bastard file almost to the scribed line. Sand to the line with a drum. This keeps the surface square to the bottom of the pan cover.
Draw file the striking surface clean. Next saw out the rest of the frizzen.
The next step is cleaning up the front of the frizzen with half round files. For me this was the hardest part of the process. It’s easy to get a slight slant on the file and change the profile of the frizzen. Doesn’t matter to much if you are making one frizzen but can be a real pain when trying for two reasonably identical parts. Use a square and check the parts by stacking them on top of each other.
Glue the frizzen blank to the pan and mount on square piece of hardwood. Drill and thread the hole for the frizzen screw. Remember to sink the clearance hole 3mm into the lock plate. This stabilizes the frizzen screw (advice from Bob Roller).
Next, I made the frizzen screws. I turned them out of 12.9 umbraco bolts. This steel is stronger and cuts cleaner than the standard 8.8 steel bolts and allows more precision. These frizzens are bridelless and a tight slip fit is needed to avoid wobble. The clearance hole in the frizzen is 5.00mm and goes about 3.00 mm into the lock plate. The unthreaded portion of the shaft should be 4.95-4.97mm in diameter. Below 4.95mm the frizzen starts to wobble on the shaft. If its over 4.97, it must be force into the hole. The diameter of the threaded portion is 4.86 after using the M5 die. The unthreaded shaft is about 2,5mm longer than the width of the frizzen toe. I had to make 6 screws to get two that fit. A good fit lets the frizzen pivot almost frictionless and without wobble. It was surprising how much difference a thousandth of an inch could make.
Make a paper pattern by tracing around the original frizzen, glue on the blanks, saw out and file to the line. Turn the frizzen over. The black superglue has left a perfect imprint of the pan. Saw and file out.
All that’s left is the final shaping of the blank with files. Mostly done by eye, but, it helps to paint with dykem and scribe guide lines to get the two frizzens reasonably identical.
Finished frizzens along with the original. Took about 20 hours to make a frizzen, not counting the time for the patterns.
Here they are after fitting to the pan. They move freely and without any wobbling. The finished shaping of the toe must wait until the frizzen springs are made. When that’s done the frizzens will be case harden.
The next part will be the tumbler, bridal and shear. Hope to finish that before xmas.
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=50191.0Best regards
Rolf
