Our newly redesigned Key Jacks support the end keys for leveling keys with a straight edge. This new design features a smooth, fine adjustment with high quality brass parts. A set screw prevents accidental turning of the thumb nut after the adjustment is established. The pair of Key Jacks includes riser platforms to increase the height adjustment range (if needed). Included items: Key Jacks, risers, case, and hex wrench.
How to use:
With the front punchings removed from A0 and C8, place the Key Jacks over the front rail pins, under the keys, and turn the knobs counterclockwise to raise the height of the end keys to achieve the target height. This provides a solid base to support your straight edge (we highly recommend the WNG straight edge).
Once adjusted, you can tighten the set screw with a 5/64" hex wrench. Do not over-tighten the set screw to avoid damaging the brass threads. It should be just tight enough to add some friction, preventing the nut from being rotated accidentally after setting your adjustment.
If you need to extend the adjustable height range, use one or both of the extra riser pieces under the Key Jack to increase the maximum height in increments from 1mm to 5mm. The thin riser adds 1mm, and the taller riser adds either 2mm or 4mm, depending on which side is face-up.