I designed this as a keychain but you could scale it up for use as a quick disconnect for many purposes. The release button is flush with the body so it will not disconnect accidentally. The engagement between the parts should be pretty firm at first and will smooth out after a few insert/removal cycles. I have lubricated both parts with PTFE to make the engagement even smoother but this step is not necessary.
The keychain is smaller than it looks. It's only 39.5mm long with BOTH parts connected, 15.3mm wide, 6.5mm high.
I have added two sizes. The "SMALL" parts are the standard keychain sizes. The larger parts are for other uses. PRINT the SMALL SIZE for KEYCHAINS.
These take me less than 10 minutes to print each.
Please post your comments and makes!
It should not require any post processing after the print. If your printer is over-extruding a bit, you might need to clean up the slot under the male part. This will help in a clean engagement.
Light sanding of the top and bottom of the male part makes engagement much smoother without requiring break in of the parts.