I created this mount for 5mm depron, but feel free to customize it for your needs, .f3d format is attached as well.
I created an extra "X plate" for spacing, because I didn't find countersunk head screws for the motor.
motor_mount.stl | 225.5KB | |
motor_mount_4_profile_v10.f3d | 229.0KB | |
motor_plate.stl | 99.1KB |