All good reasons to turn between centers.
Be wary of using a chuck to hold the work in combination with a TS centre, the work tend to walk in the chuck.
I think he's referring to chucking a Morse taper center...that wouldn't work real well.Toz, Can you tell me more about that--sorry I'm not following
When held in the chuck, as the workpiece rotates, any eccentricity in the holding of the work in the chuck jaws is exacerbated by the work being held centred at the TS end. So as the work rotates it tends to "rock" in the chuck jaws and "walk" around, becoming loose and marring the surface.
Hope I didnt make that more confusing than it sounds.............
Cheers Phil
Stuart, Not necessarily ideal. If the stickout is long then any eccentricity can be exaggerated at the unsupported end. In a perfect world you could centre drill to perfection, but in the real world the free end of the stock is "whipping" around an eliptical orbit.
If it needs accuracy then keep it short in the chuck, "knock" it square and central in the chuck, measuring with a dial indicator, then centre drill. Then extend to length and support the free end.
Cheers Phil
If you engage the drill whilst the work is stationary how can you know that you are on centre? The workpiece could have sagged. If you are applying pressure without the work rotating then you could easily cause the drill point to "skate" across the surface and be off-centre.....If the work piece is whipping to much to be safe you can start it up with the center drill in contact with the work which will suport it....
Any issue with bent stock or imperfect centering will only be greatly exaggerated by turning with it extended further out.....As you say if you drill it close to the chuck then pull it out you can get issues with any bend in the stock or imperfect centering of the chuck.