vtgaryw
Member
I got hold of a bag of 30-06 brass cartridges, so I thought I'd prep a bunch of casings for pens. Started out trying to drill a hole in the end. Turns out getting a smooth concentric hole was a lot harder than I thought it would be.
First try, I used my drill press (12" Delta with a pen blank drilling vice to hold the cartridge. Between the side play in my spindle (need new bearings maybe?) the fact that the dimples in the end were often off-center (see Pic 1), I couldn't get a smooth concentric hole to save my life.
Next, I tried my small metal lathe (and I do mean small.) It's a Poseidon, which is a Unimat 3 clone. I seldom use the tail stock, and for the life of me I couldn't get the tail stock to align with the head stock to save my life. Again, the bit wanted to follow wherever the dimple was. Again, not successful.
Third try, my pen lathe. I only have a cheap 3-draw chuck right now (MT1, not as many good options.) Once again couldn't get a true hole drilled.
Was about to give up when I started rummaging through my tools and hit upon a 3-flute, 82 degree countersink. Chucked it in the drill press, brought the table up close, and bingo! I was able to get a nice, clean, concentric countersink in there (Pic 2) that cleaned up nicely with the drill bit (Pic 3.)
I miss the access I had to a small machine shop in my last job. Nothing handy like having a Bridgeport!
Gary
First try, I used my drill press (12" Delta with a pen blank drilling vice to hold the cartridge. Between the side play in my spindle (need new bearings maybe?) the fact that the dimples in the end were often off-center (see Pic 1), I couldn't get a smooth concentric hole to save my life.
Next, I tried my small metal lathe (and I do mean small.) It's a Poseidon, which is a Unimat 3 clone. I seldom use the tail stock, and for the life of me I couldn't get the tail stock to align with the head stock to save my life. Again, the bit wanted to follow wherever the dimple was. Again, not successful.
Third try, my pen lathe. I only have a cheap 3-draw chuck right now (MT1, not as many good options.) Once again couldn't get a true hole drilled.
Was about to give up when I started rummaging through my tools and hit upon a 3-flute, 82 degree countersink. Chucked it in the drill press, brought the table up close, and bingo! I was able to get a nice, clean, concentric countersink in there (Pic 2) that cleaned up nicely with the drill bit (Pic 3.)
I miss the access I had to a small machine shop in my last job. Nothing handy like having a Bridgeport!
Gary
