Makita trimmer base 196613-4: baseplate

Replica of the baseplate of the Makita trimmer base 196613-4. As far
as I can tell, it is not possible to buy the base plate as a
separate replacement part, you have to buy the whole unit:

• Makita (German): https://www.makita.de/product/196613-4.html
• Amazon (US): https://www.amazon.com/Makita-196613-4-Compact-Router-Trimmer/dp/B07DVQ72VT/

The baseplate can be used with the Makita trimmer RT0700C, RT0702C, DRT50 and Makita clones such as KATSU and Avid Power.

I tried to model the baseplate faithfully, especially the inner ring
and the air duct.

This design is a good starting point for modifying the baseplate such
as making it bigger and/or square. Here is an example of a modified
plate for mounting on a router table: https://www.amazon.com/KETIPED-Aluminium-Woodworking-Multifunctional-Engraving/dp/B0CB6B8QZC/

I did use calipers to reverse engineer measurements, in retrospect I
could have (also) looked at commercial offers such as the one above,
because they often contain at least some measures to start with.

The part is positioned such that the surface on the print plate is the
one which should be the smoothest because it is dragged over a surface when
operating the trimmer.

Because of the inner ring (which is not strictly necessary), the part
needs some support material (1% of the print).

The baseplate comes out very solid (does not bend) with 15% infill and
Gyroid. I would be interested to hear from other people what infill
they would suggest for such a plate (it is 5.5mm thick, stress comes
from the top).

The design with FreeCAD is mostly straightforward (PartDesign workbench), except for the air duct. It is modeled with a sphere that is manually positioned followed by a cut operation that subtracts the sphere form the baseplate (Part workbench).