Ray Rogers Handcrafted Knives
Setting the Stop Bar
It's very common for the first time folder maker to agonize for hours in anticipation of drilling that first hole for the stop bar. What if it's .000000002 millimeters off? All the work I've done up to this point will be ruined by a sloppy lock!
Relax, this is easy. With just a little care and close attention to these instructions you'll be able to place the stop bar without a problem. You'll have another chance to mess up the lock a little later. :)
Start by assembling the knife using all the parts we have made except for the left side handle (be sure to include both washers). Use the donut tool you made to substitute for the left side handle so that you can snug down the blade firmly. Then mount the knife in your jig as shown below. Be sure to position the clamps so that the blade can be closed into the handle, like this:
Now get a piece of plain, round rod of the same diameter as the stop bar you plan to use. In my case, I used a piece of 1/8th drill rod that I keep for this purpose but you can use any metal rod you have, just be sure it's the same diameter as the stop bar. Do not use a drill bit.
Put the rod in the drill press and lower it to the knife in the general area where the stop bar will go. If your press has a quill lock it will be handy to lock the quill in position so that the rod is just above the surface of the handle.
Position the blade as in the picture so that about 1/16th of the end of the lock bar is covered by the blade - just enough to hold the lock down. If you put in the detent ball, try to make sure the ball is not under the blade.
Now, turn on the drill press. We do this with the press running to allow for the run out of the drill chuck. We use a smooth rod rather than a drill bit so that our knife is not damaged by this operation. Move the jig around until the spinning rod just barely touches the back ot the blade - this is easily done if you have the jig clamped into a cross sliding vise.
Very carefully, close the blade into the handle. If part of the blade hits the rod too soon then adjust the vise to clear the rod and continue until the blade is within a half inch or less of being closed. By this time, the rod should be touching the blade close to the area on the blade that we designed to rest against the blade stop. Open the blade again and see if the rod still touches the back of the blade just before the lock would release. If not, repeat the process again and refine it until the rod is in a position that just barely prevents the lock from opening and also is close to the blade stop's rest position on the blade when the knife is almost closed. This is actually much easier to do than it is to explain in writing!
In simple terms, you want to find a position for the rod that just barely prevents the lock from releasing when you try to open the blade and which will stop the blade before it sets completely into the handle. There is plenty of room to do this and not get too close to the top edge of the handle - in fact, there is a fair sized area in which any position you pick can be made to work.
The most important part is pick a spot that just barely stops the lock from releasing when the back of the blade hits the spinning rod. If you have that, and you can close the blade most of the way without binding against the rod, you're in a good spot.
OK, time to drill the hole. For this prototype I used a 1/8th barrel pivot just like the larger pivot I used for the blade so all I have to drill is a clearance sized hole. You can use any kind of stop bar you want, just drill the necessary holes. It's a good idea to start the hole with a spotting drill, then drill an undersized hole, and ream to the final size.
After the hole is drilled in the right side handle, remove the donut tool and assemble the knife completely with the left side handle. Clamp the knife back onto the jig with the right side handle facing up. Align the newly drilled stop bar hole (indicated by the red arrow) with the drill chuck. In this case, since I only needed a clearance hole I did the alignment by putting the smooth rod back in the chuck, turning on the press, and positioning the jig until the spinning rod could be carefully lowered through the stop bar hole without deflecting the rod in any direction. Because it's a clearance sized hole there is no chance the rod can jam in the hole but if you have drilled undersized for a press fit stop bar then you will need to use a smaller smooth rod. For this, I use the shaft of an old drill bit of the same size that drilled the hole with the flutes cut off of it.
With the alignment completed, mount the drill bit and drill a hole in the left side handle.
Finally! We're ready to adjust the lock ....
Adjusting the lock
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Ray Rogers Handcrafted Knives
