CNC Mill Three Jaw Chuck Adapter Plate

A bespoke adapter plate designed to hold a three jaw lathe chuck on a CNC mill table, giving the workshop a quick way to hold round parts for milling, drilling and engraving operations without a dedicated rotary fixture.

The plate locates the chuck on a machined spigot for concentricity and is bolted through on the chuck bolt pattern. The underside is designed around the mill table T slot spacing, with counterbored clamping pockets so the hold down bolts sit below the top face and clear of the cutter path. Material was removed from the outer corners to reduce weight while keeping the plate stiff enough to avoid deflection under cutting loads.

The result is a rigid, repeatable workholding solution that can be lifted on and off the table by one person and returns to the same position each time it is fitted.