The Kirsten Tool Post
Kirsten EV Tool Post
There were too many times when I lost track of where my hollowing tool cutter was located and paid dearly for it. Avoiding a sudden change from an Enclosed Vessel to “Vase” was my motivation for this new tool solution.
Enclosed Vessels(EVs) have a challenge at the entry.
Your mind’s eye focuses on where you think the cutter is and many turners, me included, tend to forget what is happening at the bore. With a normal tool post, the pivot of your tool action can slide anywhere and if too far to the back side of the bore, the tool lifts and slams down and so your Enclosed Vessel becomes that “Vase.”
This new tool post design allows you to not only register a fixed pivot location, but still easily slide in and out. The Kirsten Tool Post is very simple; providing an inexpensive tool support with a known pivot as a reference. To align, the inside of the tool pin is placed at just inside the bore tangent at the back side.This position prevents your tool from dragging on the bore and randomly enlarging it.
This placement avoids a miss on the tool face bar that will not drive the tool up. What is also important is that your left thumb pushes against the turning tool and into the pin post. Now you can concentrate on what you think is happening inside the EV and knowing exactly where you are.
The Kirsten Tool Post is composed of a rigidly welded “L” bar inserted into the lathe banjo and leveled just under the centerline of the EV by adjusting the locking collar and fixing it tight. This allows repeated use without realigning every time. A 1/10 inch collar is included to allow for an incremental rise to the tool level with smaller thickness tools while retaining the original setting.
The best application is for EVs, but the tool works just as well with open bowls.The design of the tool allows for aggressive wood removal via the fulcrum and the load that can be applied to the pin. Normally, this position had to be held rigidly with the left hand, but now is simply pushed against the pin resulting in less hand fatigue.