Some thoughts.
If you were to mount the drills a 12 inch centres, you could move the pipe 1 to 6 inches so as not to have to move the drill mounts. 11 plunges for 1" centers, 2 for 6". Have a indexable v shaped carrier as the base that moves 11 inches max. Maybe have the carrier hight adjustable for the pipe size. this would be easier than moving the drill structure up and down. Once you get it working manually you could add some form of automation controled by a PLC.
You could have an sprung inverted V shapped clamp move down with the drills to hold pipe in place.
Later add method to rotate pipe automatically. This would need rollers spaced along the carrier to make it easier for whatever method you choose.
Paul |