Cleaning Up a Pipe Center

I need this pipe center maybe twice a year and have hitherto managed to work around some nasty gouges and runout that came with it. But I finally cleaned it up by the simple expedient of dialing the compound to match the average angle (it was badly out of true) and skimming off enough to clear the surface.

The trick was realizing that the teeny little shoulder between the taper and the cone was concentric with both. I grabbed it tight (yeah, in a three-jaw chuck), took sissy cuts, and hit the end result with a file to smooth things out.

The remaining gouges are just fine by me.

Cleaned-up Pipe Center

Cleaned-up Pipe Center

It had been center-drilled in the small end, but the opening had taken a real beating at some point. Neither the live nor the dead center sat correctly and I couldn’t figure out how to hold the thing to re-drill the end.

  1. #1 by randomdreams on 2010-07-08 - 12:21

    What’s your headstock set up with? I ask because mine has a morse taper in the spindle and I’d be tempted to put the pipe center in the relevant adapter and put that in the spindle.

    Filing, or even turning, that last bit up to where the chuck jaws stick out, must’ve been tense.

    I sure wish I had one of those. I have a machining problem that needs one, and I’m probably going to have to make one on my own.

    • #2 by Ed on 2010-07-08 - 14:08

      a morse taper in the spindle

      Yup: it has a different taper than the tailstock…

      Which fact I knew because I actually turned a cylinder between centers for what might be the first time ever. Got the three-jaw chuck off without incident, too!

      I briefly considered machining an adapter, but came to my senses before even looking in the scrap bin. Cleaning up the pipe center was already pretty far into one of those exfoliating projects where everything you do requires fixing something else!

      I’ll admit I didn’t do a particularly good job with the file up near the chuck. Should I ever need that part of the cone, I’ll just switch to some other project that won’t cripple me for life.

      • #3 by randomdreams on 2010-07-08 - 15:57

        It’s been my experience that trying to cut an accurate morse taper on a lathe is an exercise in intense frustration, especially when you can get a step-down adapter, ground and hardened, for like $12. I have a smaller lathe than yours, with a 1mt in the tail and a 2mt in the head, so I got a 1-2 adapter and use it more often than I would have expected.

        I’m glad the chuck removal went smoothly this time! The fight the last time around inspired a lot of sympathy in a lot of people I know who read it and told me “you HAVE to read this one blog…”

        • #4 by Ed on 2010-07-08 - 21:17

          Somewhere in this impacted shitpile I do have a stepdown adapter, but I haven’t seen it in a long time and, with my luck, it’ll fit something useless like MT0 into the tailstock. I suppose I should get the right one when I order a box o’ cutters.

          From what I read, the pipe center is supposed to have a much steeper angle; this one was something like 37 degrees included. Probably made for some special purpose… works for my simple needs, though.

  2. #5 by david on 2010-07-08 - 15:02

    I’d just toss the center on a couple of parallels in the mill vise and indicate the center. But I bet your mill isn’t nearly tall enough for that…

    (Is that a live or dead center? If it’s live, I’d see about pressing the bearing/shaft out and working on just the body.)

    • #6 by Ed on 2010-07-08 - 15:16

      I bet your mill isn’t nearly tall enough for that…

      The Sherline? No way!

      (Nor could it chuck a center drill big enough to poke the proper shape into the end.)

      I have a larger manual mill-drill, but that starts looking like actual work…

      a live or dead center?

      Dead as the proverbial doornail.

      It looked to be turned from a round in one operation, which is why I figured the spigot (boss?) on the backside was concentric enough for my purposes. The taper has the usual flats, but oddly enough not a center drilled in the end, so they didn’t turn the taper between centers.

      The taper + spigot might be a separate piece, although I can’t convince myself there’s an actual joint back there between the spigot and the cone. I have no idea how I’d get it apart, other than by brute force, nor what I’d do with a bare-assed cone anyway.