Boring Bar Holder for the Taig Lathe

Here's a quick project for your Taig lathe. 
I often just grind up boring tools out of 1/4" HSS tool bits, but sometime a regular
carbide boring bar would suit the job better.
This piece was made using the Taig lathe and milling machine, but could be done just
as well with just the lathe and the stock Taig milling attachment for it.





Starting with a 1" cube of aluminum, mill away a part on top and bottom as shown, leaving
a piece that fits into your tool post.  I'm not noting any dimensions for this piece, as it's really
something you can do just by fitting up the piece to the tool post.






Mount the piece in your tool post and center drill a spot to start a drill bit.  Put the spot in the
approximate middle of the part that sticks out of the tool post.  It is not critical where it goes,
as long as there is sufficient material surrounding the shank of the boring bars you intend to use.
No vertical measurement is needed, as it will be the proper height as long as you drill using the
spindle on your lathe.






Drill a hole clear through the piece, starting with a 1/4" drill bit, and then further drilling it using
a 23/64" drill bit.  Finally, use a chucking reamer to ream it for 3/8".  This figure assumes you
are using 3/8" shank boring bars.  If you are using a different size boring bar shank, adjust the
size of your reamer accordingly.

What ever size reamer you end up using, the pilot hole for it should be about .015" undersized
so the reamer will have enough material to clean up for a good, straight hole of the proper size.






Back in the mill, or in the milling attachment on the lathe, drill and tap a couple of holes for
10-32 set screw threads.  Actually, you can use any reasonable size set screw you like.  I
used 10-32 screws because they are the common size for most Taig lathe fittings.

After tapping the holes you will probably need to run the reamer through the large hole due
to small burrs brought up by the tapping process.  You do not have to re-mount the piece in
the lathe to do this.  Just run the reamer through by hand, turning it the correct direction to
allow it to cut as you feed it through the hole.






Here is the finished item mounted in the standard Taig tool post.  After drilling and tapping the
set screw holes, I milled the body down a little to give it a somewhat more tidy appearance.

Thanks for having a look.


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Copyright  1998-2011 Dean Williams