Rebarreling and Home-Shop Machining

            The Indicator Extension, described in this journal, is made from .25 inch stock with a shoulder turned down and threaded #8 x 32 thread per inch. If you have ever used a hand die holder to thread this kind of shouldered bolt, you have probably found that the thread produced is either crooked or very crooked. I have purchased parts threaded this way that are also crooked, so it is not a unique problem with me.

            To help to solve this problem, I made a die head for the lathe made from a hand die holder, 0.75 inch drill rod and a good quality 0.75 inch end mill holder. I had purchased the drill rod and end mill holder previously for just such a project. The photo sequence above describes how I modified the hand die holder with a true front and back face and a bore that was true to a 4-40 screw mounted in my smallest die. The 3 inch piece of drill rod is faced, drilled ½ inch, and shouldered to fit the bored hole in the die holder. The die holder is then red Loctited in place.

             My .75 inch collet chuck which I reground (described below) worked very well for this project and resulted in runout of only 0.0002 inch for the length of the drill rod.

             Thedrilling went well at .2 inch per minute and produced a continuous chip. If you ever drill a .5 inch hole by hand, get one of these stepped drills.

             I put a 60 degree chamfer on the drilled hole with a sharp Brownells threading bit. I then used my bull-nose center to support the work. The bull nose center ran very true now that I reground it. The drilling forces and heat expanded the very end of the drill rod just a bit, so it was better to drill and then shoulder. The die head came out nice. It is a tight, no play, fit in the endmill holder, but slides easily in and out. No power need be applied to the tiny part that I plan to thread. The lathe will be used just for alignment. The die holder will also fit in the mill head as it is Morse Taper #3.

            I have also used this die head on the Homemade Transfer Screw which I describe in this Journal.

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• #2 Comment from johnstranahanbEntry Author 
  12/2/04 7:25 PM | Permalink

  dlgeary-Thanks for the comment.  Good luck.  I have used the tool several times now.  Works great.
• #1 Comment from dlgeary 
  12/2/04 11:57 AM | Permalink

  A very useful tool. I have been after such a device for some time but not wanted/had the funds to buy new. I will without doubt take inspiration and have a go at making one myself. Thanks.