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Single Pointing, It's Like Riding a Bicycle

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  • Single Pointing, It's Like Riding a Bicycle

    While trying to reorganize the garage after building my shop, I came across an old, Chinese made bench vise. It was missing one of the end caps on the handle, which had been replaced with a wad of electrical tape (by the DPO) to prevent the handle from falling out. I seized on it as an excuse to do a little lathe work.

    It was just a simple cylinder with a blind 7/16-20 (!) hole. Making the cap was easy, tapping it a little less so. The only tap I had was a bottoming tap, so it was a real grunt to get it done. When I checked the fit, there was no way it was going on. Further checking revealed that the shaft was, indeed, 7/16 and the threads were 20 tpi. The catch was that the threads appeared to have been rolled without first reducing the OD. They measured over .450 on the major diameter. Leave it to the Chinese! This presented me with the opportunity to do something I hadn't done in over 25 years, SINGLE POINTING! I parted off the cap (using kerosene because it was there), faced and chamfered the back and moved on to the shaft. I skimmed the OD of the threads to size, then grabbed a new brazed threader, mounted it in a holder and squared up the tool post. It was all coming back. The compound was already at 61 (29) degrees, that's where I always leave it. I set the pitch on the QCGB, dropped down into back gear, engaged the half-nut, brought the tool up and picked up the existing thread. Four or five passes and it was done, a perfect fit. It was all like I had done it just yesterday.

    It was such a simple job, but it brought me so much joy and satisfaction I can hardly describe it.
    It's all mind over matter.
    If you don't mind, it don't matter.

  • #2
    Congratulations! It shows how well you have learned and retained these skills.

    What gives me problems is things that require several details to watch all at once. I find that if I haven't done any TIG welding for a month or two, I am rusty and have to consciously remember each/all of the details to obtain the best looking welds.

    Best wishes to ya’ll.



    "To invent you need a good imagination and a pile of junk" - Thomas Edison

    "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

    Location: Bustling N.E. Arizona


    • #3
      I always use the phrase "like falling off a bicycle"... but whatever...

      I sometimes think that half the personal satisfaction of doing a single point thread well is the fact that we still remember how to recall, juggle and dispense all the steps in the right order enough times in a row that we end up with a usable thread. Because you're right, the actual work isn't really that big a deal.
      Chilliwack BC, Canada