Ray Rogers Handcrafted Knives
Finishing the Detent
All that remains now is to drill the hole to receive the detent ball. To start this simple process, look at the track the ball has marked on the side of the blade (barely visible in the picture below). Put a spot of marking fluid on the end of the arc. The fluid should cover the arc from about 1/8th inch from the end to about 1/8th inch beyond the end of the arc. I used a DyeChem pen but you can use fingernail polish or most anything that is soft enough for the detent ball to scrape it away.
Put the knife together and carefully close the blade fully one or two times. Do it gently, do not push the blade into the handle further than it wants to go easily. The blade should stop firmly against the stop bar.
Take the knife apart and look at the mark. You should be able to see shiny steel showing through the track cut into the dye. Look closely and you will see that the detent ball has pushed the soft dye into a little pile at the end of the arc. The top of this pile is your target.
Carefully mount the blade in your jig and take it to the drill press. I used a 1/16th diameter detent ball, so I put a 1/16th carbide spade drill into the drill chuck. Carbide spade drills do not have flutes, the tip looks like a flat pointy arrow. Theses drills are somewhat delicate but they can drill a hole into a hardened blade if used carefully. The shape of their point makes a dent that seems to work well for the detent.
Position the tip of the spade drill directly over the top of the pile of dye at the end of the arc with the drill press turned off. I use extra magnifying lenses on my glasses to makes this easier. Look at the set up from as many directions as you can. Your goal is to make the tip of the drill come down on that pile of dye and make a dent 1/16th in diameter that is centered on the arc. This would be the ideal result, but if you are off a little one way or another it won't be enough to keep the ball from working if you do your job carefully. When you think the drill is positioned, turn on the drill press and look again with it running. If the point has moved, make the necessary small correction. Then, lightly touch the tip of the drill to the blade. The tip should make a small shiny spot in the dye and give you one last opportunity to adjust the position.
Now, drill your dent. Let the drill go into the metal no more than the full width of the tip of the drill.
Once you are done and the dye has been cleaned away, your blade should have a tiny dent where the green arrow is pointing.
In the picture below you can see where I have cut a relief in the handle for the thumb stud when the blade is closed. Be sure the relief notch clears the thumb stud - the stud should not touch the handle.
Assemble your knife and you are done.
Here is a picture of all the parts we made. The blade and one of the handle slabs are your patterns for building the real knife, complete with all the holes located. Just remember when you use the blade for a pattern to leave some extra metal at the back of the blade. Also, do not try to cut the locking notch in the blade when you first profile your next blade. Wait until after the blade is heat treated, then grind the notch and follow the rest of the process for marking the liner and cutting and fitting the lock.
With just a little imagination, the patterns and techniques you have developed can be used to make real knives:
And finally, we are back where we started with our nickle knife. I hope you found this tutorial useful. If you have comments or suggestions for improvements to this tutorial, my email address is on the bottom of the page...
Pictures of Knives by Students of this Tutorial
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Ray Rogers Handcrafted Knives