Hello, everyone. I hope that you all had a great weekend. It's time for some updates on the Bobcat build.
After spotting the screw holes, I drill blind holes into the backsides of the bolsters. These holes get tapped with 0-80 threads to accept the screws that will attach them to the liners.
Here is the new idea for the hidden screws that I came up with. In the photo you can see a liner fastened to my mill and a 1/16" endmill mounted in the spindle. On the very right side of the liner you can see a keyhole slot that I cut in which will allow the head of the screw to push through the large hole and slide down the slot to the correct alignment. I use a small piece of wood to back up the cut so that I don't damage my milling plate with the through cuts. These slots must be parallel in order to work properly.
These next few photos will show how the feature works. The screws are inserted into the bolsters and screwed partially in. You can see on the inside of the liner that the top of the keyhole has a chamfer. This is so that the head of the screw can drop below the surface of the liner and not interfere with the pivot of the blade.
Here, the heads of the screws pass through the large openings at the bottom of the keyholes.
The bolster is pushed upwards and the screws slide through the slots into the top chamfered holes.
And the screws are tightened down. The bolster is now held tightly in place. Worked like a dream! I can't tell you how much frustration this is going to save me trying to get those tiny screws lined up freehand when assembling the knife. I'm pretty excited.
Now it's on to the scales. The scales need a 30 degree bevel on the front faces in order to dovetail with the bolsters. To do this, I use my grinder with the table rotated forward at 30 degrees. I grind slowly as not to overheat and burn the mammoth.
The fit up looks good. No light passes through the joint, indicating a tight fit.
Now we need a way to screw the scales onto the liners. Since screws won't hold in the mammoth alone, I epoxy some thin disks of stainless steel into recesses that I milled into the backs. I've show this before on other builds with hidden screws. Now, we wait for the epoxy to cure and grind the faces of the disks off flat with the scales.
Well, that ends this weeks adventures in knifemaking. Next week I hope to get the scales attached, the handles all profiled, and maybe the blade ready for heat treat. Thanks for tagging along with me on this build. Have a great week!
- Brandant Robinson