How can I place a point on a curved face and make a normal

[jr23mx]

Hello all

In the following picture I graph the normal but it is going on the opposite direction I expected.

How can I place first a point on the selected face if it is curved? or how can I make a normal to outside of the body like the red arrow.

I attach the part file

snap0000029.png (79.77 KiB) Viewed 430 times

[microelly2]

see tripod of the nurbw wb
https://youtu.be/fScyrV9fB80

[chrisb]

It is more convenient if you upload the FreeCAD file and not a step.

The curved surface follows an arc, so it's easy. In the attached example I created a sketch and created a line normal to the surface.