This item is meant for temporarily yet securely mounting an ADXL345 accelerometer to a printbed for resonance calibration. Made for Ender 3v2, but should work for almost any bedslinger.

Print the item on its side so you won't need supports and it will be as strong as possible.

Print settings:
3 walls
20% infill (doesn't really matter)

You're going to need three M3 screws.
1x M3x10mm (or longer) for mounting to the bed
2x M3x4mm (4-8mm, I used 5mm) for mounting the ADXL345 accelerometer to the adapter