Are you referring to a boring head or stones to hone cylinder's ? The chatter when using a drill press of any type is my question. I do not doubt that it's not impossible to construct a home made boring bar. I have complete confidence that the machinist I knew who BTW had a stellar reputation, could fabricate one. But the question is why? When does practicality come into play? I dont know if your a machinist and understand machine shop theory or a experienced engine builder but there is a lot of factors needed to be considered