Reply To: New Mill

[david pierce]

Tom,
I just read your new blog. It looks like the mill is OK but the drill chuck that came with the machine is not a super high precision item. It also looks like the Jacobs chuck and the collet have about the same runout; .0005 sounds pretty good to me. The wobble could have been caused by the drill bit. Did you center drill the spot first? Was it prick punched?. It is normal for a twist drill to skate around the surface of a plate if it used without center drilling the plate first. Drill bits are available that can be used without center drilling first and are called split point drill bits. They are much shorter than jobber length drill bits and are usually sold as individual sizes in packs of 12. Machine shops use them to save time because a center drill operation is not required. They are usually used on turret lathes (CNC) or CNC machining centers where operations are timed to seconds.
david