I need to make a tapered slot in the side of aluminum or steel round stock (work piece). See the pics. Ten of these are needed. They will fit to another piece which is not relevant to the problem at hand.
The round stock shown is 1" long if aluminum or 1.25" long if steel. The diameter is 1/2". The tapered slot is 1/8" wide and 1/4" tall on one side of the work piece. The slot tapers down to a 1/8" diameter hole on the other side of the work piece. The long sides of the slot are straight. The "floor" of the slot is round with a 1/16" radius. So is the "roof" inside the angled slot. I calculate the angle of the taper (top of slot) at 14 degrees, from horizontal, with the pin standing vertically as shown, but I could be wrong on that. The bottom of the slot is at 0 degrees from horizontal, with pin standing vertically as shown.
I can easily cross drill a 1/8" hole to make the bottom part of the slot. But making the tapered part stumps me. I could make a 14 degree wood triangle, angle the pin in the vise, and go at with a 1/8" endmill, but it would have to go in slightly further than 1/2" (due to slope of slot and resultant increased distance), and the endmill cutting surface is only 1/2" long. Even if it could reach as far as needed, I am nervous about breaking the endmill, even if in aluminum, much less steel.
My tools are a 1946 Southbend 9" lathe and a 1951 horizontal/vertical knee mill (Rotex, w/5 x 20 table).
Any ideas are welcome.
Thank you.
Phil
The round stock shown is 1" long if aluminum or 1.25" long if steel. The diameter is 1/2". The tapered slot is 1/8" wide and 1/4" tall on one side of the work piece. The slot tapers down to a 1/8" diameter hole on the other side of the work piece. The long sides of the slot are straight. The "floor" of the slot is round with a 1/16" radius. So is the "roof" inside the angled slot. I calculate the angle of the taper (top of slot) at 14 degrees, from horizontal, with the pin standing vertically as shown, but I could be wrong on that. The bottom of the slot is at 0 degrees from horizontal, with pin standing vertically as shown.
I can easily cross drill a 1/8" hole to make the bottom part of the slot. But making the tapered part stumps me. I could make a 14 degree wood triangle, angle the pin in the vise, and go at with a 1/8" endmill, but it would have to go in slightly further than 1/2" (due to slope of slot and resultant increased distance), and the endmill cutting surface is only 1/2" long. Even if it could reach as far as needed, I am nervous about breaking the endmill, even if in aluminum, much less steel.
My tools are a 1946 Southbend 9" lathe and a 1951 horizontal/vertical knee mill (Rotex, w/5 x 20 table).
Any ideas are welcome.
Thank you.
Phil