This is my approach to build a little travel scale in the size of a credit card (it's a little bit thicker ;-) )

it is possible to measure up to 2 kilograms and you can distinguish between 0,5 - 1- 1,5 and 2 kg

It is printed in some no-name Silk PLA+, 0.2mm layer hight, 20% infill

Measurement of 1kg	Measurement of 2kg

There are 5 markings on the pin:

weights larger than 2 kg will be blocked by the frame to avoid damage of the spring

If you use your own material the scale on pin has to be adjusted.

simple assembly:

you can store it for transportation