Project Information
The process described below has more detail than most of my projects as this was my very first knife scale project and I want to document for my own reference. The knife in question is over 50 years old and has some sentimental value. As the opening photo show the blade was dull enough to handle without any danger of cuts.
The other two photos show the original knife scales and the plywood cutouts.
I traced the old knife handle, scanned it and used the bitmap as the bases for the tool paths. I added a pocket large enough to allow the thickness of the blade, ~.026 per side. I did not include any holes for the blade pins as they would be transferred from the blade directly to the two scales.
I cut a prototype out of .375" plywood with a .250" router bit (a router bit that needs to be retired) and by mistake used climb cutting which made a lot of noise and left very raw edge. Otherwise everything else was as expected including the blade relief depth.
I replaced the plywood with the .3" teak and machined it with a 3 flute milling cutter. During the first cutout I realized I forgot to reset the depth from .375" to .3" and proceeded to "engrave" the spoil board.
Setup:
Material: 0.3" teak
M.A. FORD #138250001, ¼"× ½", X-AL 3 Flute end mill
16000 RPM
2.0 in/sec, 120 inches/minute
0.5 in/sec plunge rate
Resetting the depth to .3" I cut a leftover scrap from the first mistake. That scrap leftover piece shattered because I set the depth of cut passes to 2, ~.150" per pass, way to much cut for thin material. I corrected that to 8 passed and I machined the last two pieces.
The blade relief pocket was not as uniform as I would have liked because the wood was slightly bowed and the edges had some chatter marks which, in this case, was not important as the assembly will be sanded.
I mounted the knife blade to one of the scales to locate and drill the blade mount holes and repeated that for the opposite side scale. The knife blade actually had three holes but the center pin was not used in the original so I didn't use it either and therefore allowing another glue spot.
I purchased some 5/32" diameter low lead content brass rod (RoHS compliant) from McMaster-Carr for the blade pins.
After press fitting two ½" pieces of the brass rod into the blade I applied West System G/flex 650 the two scales and to the blade. Adding two drilled gluing cawls to both sides of the assembly and mounting the assembly in a vise I carefully "pressed" the two scales together on the blade.
After 24 hours in a very warm garage, I sanded the scales. The photos shown do not have any finish because I don't know if I want to use CA or more of the West Systems epoxy.
Most knife crafters on Lumberjocks will probably get a chuckle out of my excruciatingly verbose description of such a simple project!
The other two photos show the original knife scales and the plywood cutouts.
I traced the old knife handle, scanned it and used the bitmap as the bases for the tool paths. I added a pocket large enough to allow the thickness of the blade, ~.026 per side. I did not include any holes for the blade pins as they would be transferred from the blade directly to the two scales.
I cut a prototype out of .375" plywood with a .250" router bit (a router bit that needs to be retired) and by mistake used climb cutting which made a lot of noise and left very raw edge. Otherwise everything else was as expected including the blade relief depth.
I replaced the plywood with the .3" teak and machined it with a 3 flute milling cutter. During the first cutout I realized I forgot to reset the depth from .375" to .3" and proceeded to "engrave" the spoil board.
Setup:
Material: 0.3" teak
M.A. FORD #138250001, ¼"× ½", X-AL 3 Flute end mill
16000 RPM
2.0 in/sec, 120 inches/minute
0.5 in/sec plunge rate
Resetting the depth to .3" I cut a leftover scrap from the first mistake. That scrap leftover piece shattered because I set the depth of cut passes to 2, ~.150" per pass, way to much cut for thin material. I corrected that to 8 passed and I machined the last two pieces.
The blade relief pocket was not as uniform as I would have liked because the wood was slightly bowed and the edges had some chatter marks which, in this case, was not important as the assembly will be sanded.
I mounted the knife blade to one of the scales to locate and drill the blade mount holes and repeated that for the opposite side scale. The knife blade actually had three holes but the center pin was not used in the original so I didn't use it either and therefore allowing another glue spot.
I purchased some 5/32" diameter low lead content brass rod (RoHS compliant) from McMaster-Carr for the blade pins.
After press fitting two ½" pieces of the brass rod into the blade I applied West System G/flex 650 the two scales and to the blade. Adding two drilled gluing cawls to both sides of the assembly and mounting the assembly in a vise I carefully "pressed" the two scales together on the blade.
After 24 hours in a very warm garage, I sanded the scales. The photos shown do not have any finish because I don't know if I want to use CA or more of the West Systems epoxy.
Most knife crafters on Lumberjocks will probably get a chuckle out of my excruciatingly verbose description of such a simple project!