Well, everything takes longer than you think it's gonna. No rings or acrylic today, but I got out 10
sweeeeeet P1 emitter collars. I've got it down to a science now, and I've got it up to two per hour. I bet I can get it up to three. We'll see -- I have the lathe at 6 again tomorrow and my intention is to just run out my 1/4" stock, and then hopefully run out my aluminum ring stock too. Yay!
I made 10 of them, but the first four were rejects. The other six were perfect. So now that I've got the process working
really well, here's how I do them:
I start with 1/4" solid rod stock. Yes, I know I said it might be a bad idea not to turn things down from larger stock, but I was younger then, naîve, fey, insouciant, and full of Shat.
Thou shalt not take my name in vain, you little Shat.
Anyhoo, starting with 1/4" stock saved oodles of time. Also, this job requires two tools, and I did the piece backwards from how I did it the other day. That means the front of the collar sticks out at the end of the stock, and I turn down the thinner part
behind it. Worked way better that way.
The stock is cut down to roughly 3" lengths on the bandsaw, which today happened to be razor sharp and full of unicorn magic. I cut half a dozen pieces in mere seconds. Much more nicer than using the butter knife they usually have mounted on there.
Gotta be careful when mounting it. Remember,
it can only stick out by 4x its diameter, which in this case would be 1". I come out just a hair under that.
Once the stock is in the chuck, I face it off. Then I file the leading edge just to make it a hair less sharp, and finally hit the whole outside with scotch brite. Since the stock is very clean already and it's the right size, I don't want to do a finish pass on it. The scotch brite makes it look great anyway.
Then it's time for the hole. Make a dimple with the center drill, then go in with
a 1/8" bit, and then the
3/16" bit. Important note: The whole piece is 1/2" long, and so I only
drill to a depth of 5/8". I discovered I get bad results if I try to drill as deep as I can so I can get two pieces from one drilling operation. They come out better when I drill each one new, and it only takes a couple of minutes.
To get the right drill depth, I use the markings on the shaft of the tailstock.
Once the hole is done, I put my cutting tool on, and line the point up to the leading edge of the workpiece so I have a reference point for the front of the piece. Then I
set the digital readout (DRO) to 0".
Now you just turn the crank for the X axis so the tool travels back exactly 0.250", and there you go -- your front end will now be exactly 1/4" long. The direction of the cut is going to be
toward the chuck (which means you have to be
very alert and careful, or you'll crash your tools into the chuck).
Now you set the DRO to 0" again. So when you make your cuts, you just bring the tool back to 0, and make your next pass. All it takes is three or four passes, and I use the auto-feed (
very dangerous this close to the chuck unless you're
very careful) to get a nice, even finish. Now, if you look carefully, you can see I'm cutting the shaft a bit longer than it needs to be. It's actually about 0.265" long at this point. That's just a little extra to make the parting easier.
Now here's where the magic happens -- I pull the tool back to exactly 0.250" so that my part will be exactly the right length. Then I stick a copper wire in the front of the piece.
That's there to keep the piece from falling into the chip tray when it comes off. Trust me, there are better things to do than carefully go through shredded metal looking for your part. Such as starting your next part.
So now I just nudge the tool forward. That wall's very thin now, so it just falls right off with a beautiful finish.
Now, I just switch tools and face off the front of the stock again...
And do it over. Just lather, rinse, repeat until you get this:
That's the JL piece on its side in front, the six perfect ones in the middle ground, and the four flawed ones in back. After a second look, they're actually still useable.
So that was today's work. Tomorrow, I'm laser-cutting acrylic P1 readout covers (or whatever they're called), and then hopping back on the lathe at 6 to finish out my 1/4" brass stock and my aluminum tube. That's the
plan, anyway. My mileage may vary.