One thing that can be difficult to achieve with a disabled hand, is clipping the other hand's nails.

Some commercial helpers exist, but I thought that there was room for improvement, in particular for people with weaker arms (and hard nails). This design attempts to provide a more comfortable, cheap solution to this problem, and can be customized to fit different clippers. I have put a photo of the one I got from Carrefour.

Design

The system is made of a lever mechanism (using print-in-place hinges) to amplify a light downward force on the handle into a stronger clipping action. It was inspired by this existing design, which provides a lever action relying on a flexible handle. One issue of this existing model is that the clippers' slot dimensions cannot fit every clippers on the market. I also wanted something with a wider base for more stability. Finally, I chose to incline the clippers upwards, in a more comfortable position

Customization and build

To adapt to various clippers models, the design needs to be parameterized according to the clippers' geometry, as explained bellow. The values should not be too different, for a “regular” clippers (the one I used is 80mm long). I took pictures of the clippers to make the modeling and initial measurements, but it should be OK to measure directly, for example with a caliper and then adjust the values using the quick test prints until the fit is satisfactory (which I did).

Then, you just need to generate the model with OpenSCAD (uncomment the relevant lines in nail_clippers.scad), print the two parts, assemble them with two M3x6 screws (or glue), insert the clippers and optionally secure it with one more screw. I also advise putting adhesive pads under the legs for stability (there are centering marks).