Tried two different ways to set up a boring bar for a deep hole job

Had to bore a 2.5 inch hole 8 inches deep in some 4140 last week. First, I set it up like I always have, just eyeballing the center height with a steel rule and locking it down. The finish was okay, but I got a bit of chatter about 5 inches in. My lead guy saw me resetting and told me to try using a coaxial indicator to find center and then pre-load the bar by taking a light cut, backing off, and re-tightening the set screws. The difference was night and day. The second part ran smooth as glass, no chatter at all, and the surface finish was way better. It added maybe 3 minutes to the setup, but saved me time on the cycle and a better part. Anyone else have a specific boring bar setup trick that made a big difference for you?

3 comments

3 Comments

the_max1mo ago

Pre-loading is the secret sauce.

rosecarr1mo ago

But what about when pre-loading goes wrong and locks up the whole system? @the_max, that secret sauce can sometimes be a real recipe for disaster if it's not done just right.

abbyf791mo ago

Our app pre-loaded 500 assets and crashed for a solid hour. That sauce definitely burned us once!