Summary

This simple lever can be used to precisely level the bed of a 2-head printer. While designed specifically for the X3Machines' Lorei, it should work with any printer. The needle movement exaggerates the the Z-axis distance under the print nozzle by a factor of more that 20X. With practice, you can level the bed in less that 5 minutes with high accuracy.

Steps for leveling the Lorei:

1. Make sure the printer is off and cool.
2. Back all leveling screws fully out so that the bed sits firmly on all 4 rests
3. Find the highest corner with respect to X-axis arm:
   a: Move the printer head as close to the front-left screw as possible (by moving the bed and/or printer heads)
   b. Lower the head onto the short-side of the lever until the left nozzle is in the lever's groove and the lever pointer is pointing right at the base.
   c. Now without changing the Z-axis height, move the head as close to the 3 remaining leveling screws and observe the lever pointer. The corner where the lever pointer is the highest is your highest corner. You will not adjust this screw.
   d. At the highest corner, adjust the left head height until the lever is pointing even with the base frame.
4. Move the left print head and lever to the corner opposite the highest along the Y-axis. (For example, if your highest corner was the right-rear, move to the right-front corner.) Use the leveling screw to raise the height of the bed until the pointer is even with its frame.
5. Now move the right print head and lever to the corner opposite the highest along the X-axis. (For example, if you highest corner was the right-rear, move to the left-rear corner.) Raise the leveling screw until the pointer is even with its frame.
6. Repeat Step 4 with remaining screw.
7. Now both nozzles should be equidistant above the bed and horizontal in the Y-axis. Visually inspect and tweak after making a test print.

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/4B1J2DeTNWv