Here is a collection of a few fully printable torque wrenches.
The actual torque is dependent on the material, print settings and spring width. All sizes are available with 3 spring widths (1.5mm, 2mm and 2.5mm) to give some degree of freedom in achieving the desired torque. The arc provides a place to add a scale. This will require a calibration with a known torque. Adding some sort of pointy indicator is probably also useful in that case.
The files are named after the width of the wrench and the width of the spring. To give an example: 5p6w_2 will have a wrench size of 5.6mm and a spring thickness of 2mm.
I got decent results using the following settings with the 8.1mm wrench having a 1.5mm spring for SMA connectors:
top- and bottom: 4 layers
If you could use another wrench size feel free to contact me.