Quote Originally Posted by Saltfever View Post
Not knowing the design of your drill press I can’t forecast the effect of your idea. However, I see some considerations. You are reversing the thrust of the Z axis. Are the spindle bearings suitable for this change? Normally, I grip the collar around the column to lift the table up. You have created a bending moment that is now putting stress on both the table collar and the column. How will this affect wear of these two parts?
Very good points that I had not considered. It makes sense that the bearings were not designed for a downward force.

The center of gravity of the empty table should be close to that center hole so this would be the ideal lifting point with respect to bending forces. However, it is a terrible place to lift because it is right in the middle of the action when subsequently drilling. Place a heavy vise on the table puts even more weight near the center of gravity.

I've started to think about keeping the jack screw idea but not driven by the drill press. Although it adds complexity, a pinion gear that let me turn this screw from a drive shaft under the table would be cool. I could turn the drive shaft with my battery powered drill.

I like lifting the table near its center of gravity but the mechanism must be out of the way. It could swing out as needed under the table if not too much hassle. Maybe it could stay there. Clearly, thrust bearings would be good.

More comments from others plus think time will refine this.

Thanks!

Rick