I find boring bars exciting.
I have a boring head for my milling machine, which is excellent (indispensable) for milling holes to a certain diameter in square stock. But for round stock in my lathe I’ve been messing around with various cutters with mixed results while trying to cut the inner diameter of various projects.
Boring bars are the correct tool for the job on a lathe, but I don’t have any. Even if I did, I don’t have a holder.
I decided to rectify this situation by making a holder that would accept the cutters from my boring head set.
When I made my quick-change tool post, I milled a dovetail into a large block of steel. The idea is that I can cut off chunks as needed to make various tool holders without having to mill a new dovetail.
I sliced off a chunk with my portable bandsaw, cleaned up the shavings, and then milled it down to a more appropriate size.
I drilled a starter hole in one end and through the full length of the workpiece.
In order to check by progress while boring the hole, I had to move the workpiece out from under the cutter and fit some calipers into the hole. My DRO proved very helpful for this: I could set the axis to 0, move the table to get the workpiece to a measurable location, and then move it back till the DRO read 0 again. It perfectly relocated the hole under the boring head every time.
I set the workpiece on its side and drilled 2 holes through to the 1/2-inch hole, which I then tapped out with 1/4-20 threads for set screws (i once again use the DRO to relocate the holes after changing the drill bit out for the thread tap)