eBay Reground Cam

Watch the tip of your DI as the lifter rises and falls.
If it moves sideways in any direction, the axis of the DI is not the came as the axis of the lifter, and it will not read correctly;
because the DI-tip is climbing up the side of the cup.
If you make a flat plate to sit in the recess, and your DI-tip scrubs sideways..... see above.