Quick Change Indexable Tool Holder
Modifying John's Design
John's design is sized for a larger machine. A second write up on constructing it has been provided by Kevin Ferguson. It was scaled it down for the
7x12 and converted to metric. Since the FrankenSieg doesn't need the
compound, the tool block will be considerably taller. The most significant
change was to reverse the dovetails, having the female on the tool holder
instead of the tool block. This has the effect of cutting away the corner
closest to the tailstock, increasing clearance.
To maximise the size of the clamping wedges, offset the central hole for
the mounting stud by 2mm to the corner with two dovetails. This allows the use of
16mm diameter wedges. This also reduces the overhang of the tooling from the
pivet a little.
John's design has an anti-rotation feature on both the front and side
wedges, but this can be deleted from the front wedge, as the slot with the
side wedge passing through it acts to prevent rotation.