Holes on inside of shell of shelled spheres not fulling extending

[gavin_rj]

I have a 100 mm hollowed sphere with a two millimeter shell. When I dig a hole from the inside face of the sphere, because it is a rounded surface, there is a flat plane formed at the beginning and then the rest of the hole is dug, as it digs from the center point of the start of the hole on the chosen face. 

I can then complete the hole by extruding. Alternatively, I can create the hole in the first place by extruding. 

Is this expected behavior? Is there a way to set the parameter for hole depth to begin from a negative depth?

[jhackney1972]

I assume you are creating the hole from the inside of the sphere.  If so, the "All" depth option, in the Hole command will take care of the problem.  If creating the hole from the outside, the "To" depth option, and selecting the inside face of the sphere, should do the job also.

[gavin_rj]

I only want the hole to come partially through from the inside. 

[jhackney1972 · Accepted solution]

In that case follow the video example. Model attached.