By Steve Jasik
A quick-change toolholder is one of the best purchases I ever made. Having a number of pre-set tools waiting to be dropped-in really speeds up just about any lathe job. The one thing that can slow the process down is when the toolholder or top slide (or both) must be rotated for work clearance, etc. Things must be re-aligned before the pre-set tools can be used again – don’t try parting with your parting blade at an angle to the work!
The simple fixture seen in Photo 1 will reset my top slide and toolholder when things get out of kilter and takes just seconds to use. I no longer need to drag out the 1-2-3 blocks and the protractor to get the toolholder square to the spindle.
The angle I used for my gauge is 29-1/2°, as this is the angle I typically have the top slide set to. My Hardinge Toolroom lathe clone has nice square corners to work with and it’s easy to set the top slide with the gauge. Once the top slide is back to 29-1/2°, the toolholder can be set (Photo 2).