I made a variation on a model I found on thingiverse for my 3D Printer.
I am using a 21mm X 2mm slot for a 1 Penny coin to be inserted into my model during the print. I simply pause the print at the 13th layer. Assuming a 0.3mm print layer height.
Insert the coin and resume printing. Et voila !
Overall printing time is about 30 minutes with 75% infill (for the rigidity), 2 shells, no raft, no support printed in PLA.
It has a key chain attachment so that you can carry it around with you all the time…
