Use these bolts & nuts for the take apart toys listed below:
The bolts could optional be reinforced, in case of poor layer bounding. A steel bolt M3x30 and nut will certainly strengthening the printed bolt.
The screw driver set is also open source and could be downloaded here also. When using one handle for all bits, D6L6 magnets could be inserted during printing.
Alternative, the torque limited screw driver (using same bits), could be downloaded from thingiverse:
After a short parameter study, decided to make the inside of the nut_v1 a little larger for dealing with FDM issue's printing an inner circle.
Although care is been taken, getting all dimension right, it's challenging to print these bolts & nuts.
I do get better results printing these in ABS then PLA somehow.
The parts using same geometry, are printed with PLA, which is a working well.