View Full Version : Boring Head Question

01-09-2009, 04:00 PM
I bought a cheap import boring head, which probably already answers my question. I put it in the mill and set up a DI on a 3/4 shaft clamped in the head and when I rotate the head I get some runout. Adjusting the offset screw I can get it perfect front to back but get .005 from side to side. When I say side to side, I mean measuring the gib side then rotating the head 180 and measuring the other side. I wouldn't think this is normal but what do I know.

01-09-2009, 04:11 PM
Unless I'm missing something...why does it matter, except that it may be aesthetically displeasing? Assuming everything is rigid, the boring tool will make a circular cut.

brian Rupnow
01-09-2009, 04:13 PM
Why would it really matter. When you use a boring head on a mill, you drill a clearance hole in the part to be bored first, then put the boring head in place with a boring tool and keep advancing the cutter and taking cuts untill you reach the desired hole size. I don't see where run out comes into the picture at all. What am I not understanding here???

01-09-2009, 04:26 PM
The .005 measurement is greater than when measuring for the offset so it seems that it would overbore the hole by 10 thou. Maybe I'm the one missing something.

01-09-2009, 04:35 PM
Never mind:D I just realized the error in my thinking. As long as the cutter is parallel with the offset movement of the head it wont make a difference.