Taig Lathe – Boring Tool Holder
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This is the boring tool holder, just after completion. It never looked this good, again.
The holder has two holes, to accommodate two different boring tool diameters: 5/16″ and 3/8″. In use, after inserting a boring tool, the tool is rotated until the tip of the cutting edge is at centre height, and then the grub screws are tightened to hold it there.
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Here, I'm drilling grub screw holes.
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This is the bottom of the tool holder, showing relief to ensure that the clamping force will be applied around the outer edges.
If you look at the underside of a Taig lathe tool holder, you'll see the same sort of relief.
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Here, I'm drilling a hole, enlarging a smaller hole.
Drilling in the lathe is, of course, the simplest way to ensure that the hole is at centre height.
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Here, I'm drilling a hole, then enlarging the hole some more, working up to the desired size. The drill chuck won't handle these larger drill bits, so I switched to a three-jaw chuck.
If you try this, take care that the drilling forces don't drive the bit back into the headstock taper, marring it.
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After drilling a hole close to the desired size, I substituted a milling bit to enlarge the hole to the final size. It's my experience that an end mill produces a hole to a desired size very accurately.
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This is how I “make it pretty”. Generally, I start with an 800-grit paper and work down through finer grades until I have the finish I desire. Then I may or may not use a bit of metal polish.
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Two dowels in the base keep the tool holder aligned with a T-slot. I added these after using the tool holder and finding that it wanted to twist arond the mounting screw.
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Here it is in use, using one of those inexpensive carbide cutters, mounted in the larger of the two holes.