Gap between the 3d model // plataform

3dmodel object and action ‘separate from plataform’ is giving me a gap between the 3d model // plataform

What is the expected result

I expected the bottom of the 3dmodel touching the plataform with no gap

What is the actual result

3dmodel object and action ‘separate from plataform’ is giving me a gap between the 3d model // plataform