A hangboard to train you fingers/grip for climbing have 3 different levels of 30-20-10mm. 
Made them to screw into the well above a doorframe.  
Bolt hole are for m6 and also added a standard washer (m6 with 12mm outer diameter) to destribute the load.

Did not print solid but added 8 parameters on walls and 8 on bottom. A bit overkill but hold med fine at a 105kg.

Added griptape on the surfaces.