This is a model of a spaceship engine I designed in Fusion 360. There is a section of the engine that prints in place inside the bottom of the model that is then free to move up and down when the model is done. This model is scalable.

The correct printing orientation is with the engine facing upwards so both the outer part and the print in place part are touching the bed.

A brim is recommended to make sure the model does not fall over during printing.

At 100% scale there is a defect with the thin perimeters at the top of the model if you have detect thin walls enabled, to fix this just disable that feature.