This is used to level the HBP on a Makerbot Replicator. Holds a Power fist 2.25" Deflection Gauge (.375" center mount) & 4 Rare earth magnets (8mmx3mm). Both are available from Princess Auto in Canada Gauge #2970986 - $18.99 & Magnets #8183915 - $2.49. When fully inserted there's only about 2.5mm pressure on the gauge spring, so the HBP does not deflect.
Printed at .27, 15% infill, 1 shell. Default Speed.
Insert the Deflection Gauge into the holder until it's flush with the bottom. Home your Axis, position the nozzle just in front of the right-back screw. Use your piece of paper or feeler gauge. Place the gauge on the carraige rods, it can easily slide around on the rods! Adjust until you get zero everywhere :)
I based this off of Heathzaps tinkercad object, as his applied too much downward force on the HBP and my gauge or magnets did not fit.
I also extended the area downwards around the rods so it does not move when moving it around.
Original Tinkercad object: