There are 2 sizes depending on the pill’s size. Thyroid medication is a very small pill and is taken alone on an empty stomach. The container has a lid marked ‘Thyroid’ but there is also a lid with no label for a small pill such as for heart pain.
M4 nuts and bolts are used. For the small container an M4 6mm bolt and for the large container an M4 13-20 mm bolt is needed. I find that a nyloc nut does not work well but some type of locking is needed – I use Loctite Blue.
Printing with PLA works very well. For the lid print as present with a ‘tree support’ for the center bolt recess. The support is easily removed with an Allen driver pushing through the hole. The lettering is clear if your printer is calibrated. I use a 0.6 nozzle with no problem. Print with the inside curves first and limit crossing. Three layers and 20% infill.
After printing a very light sanding over the lettering will make it smoother so the lid rotates easily. Also, the slight ramp on the underside of the lid needs to be smooth.
This design has been developed over several months and has had many variations.
For travel you can safely through it into your bag a be sure it will be safe at the other end. Personally, I use black plastic for my night medications and white for my morning medication.