A different style boring head

[Frank S]

This thread is old enough now that I guess it needs an update. Some of my observations after I made it and used it several times. #1 it is not as easy to index for bore diameters as a dovetail head would be. #2 after through drilling it from the bottom part into the top part and threading it for a 5/16-18 clamping bolt it did help with stability #3 the range of adjustment as I made it was a little lacking This could have been overcome by making the whole thing a larger diameter with slightly more eccentric offset and if I were to make another one like it, I would make the eccentric stem longer for stability. However, if I were to make another, I probably wouldn't use the eccentric design at all just take the extra time and make a dovetail boring head, the problem with that though is I still don't have any dovetail cutters.
Ther is a consolation to a design of this type though. For someone with limited tooling or experience a boring head such as this would be an easier build and with some careful measuring you can achieve satisfactory results for about any bore you need to make providing you take your time. I am a little too impatient at times when it comes to running a mill, I just want to hog my way through the initial cuts and do a single final cleanup like I can do on a lathe, which is not a good practice especially with smaller machines I'm a T50 or MT7 type guy. The concept of an ER11 collet is as foreign to me as a bb gun would be to a gunner's mate on a battleship