The dimensions of the original design are perfect, I printed it with PETG and it works perfectly. I have included my step file
The author remixed this model.
The changes I have made are as follows:
1) I turned the plate 180° from the original idea, because I absolutely wanted the cables for the motor to go directly to it without getting in the way
2) I wanted to position the receiver towards the front for proper cable management
3) I raised the walls where the receiver is placed to obtain space for the positioning of the clamps