I have Fenix 3 Watch.
As you know if you read this post, a great accessory!
However, I have only one charging cable and I am scared to lose/break the charging cable. I want 2 charging options, one to leave at home, and one to take with me when I go to work/travel, etc.
I printed this clip-on adapter for the watch and a wall charger to carry with me.
Can also be used if you have the watch without an adapter.
It makes sense to add the support blocker in Cura and not to print on the contacts area (I have printed successfully with full supports and partial supports as in the picture).
If you use full supports you battle to get the contact areas clean.
This prints so quick, figure out what is best for you.
As the tolerances are so small, Filament temperature, support spacings, etc will all affect the outcome.
Adding the Contacts
This is the most difficult.
I used a needle to open the 2 holes for electrical contacts. Then I put the wire connectors through the little holes.
Split the 2 Contacts.
It is important to crack the line between the contacts and let the 2 contacts press independently onto the connection points. If you don't, the one contact will always make good contact whereby the other is kept away from the contact area. By cracking the little line, the 2 contact points move independently and press equally on the watch to pake good electrical contact.
Power supply and Polairity
I have tested a few Cellphone USB power supplies.
The best one was a "Cheapy" one that delivered 5.0V. The higher quality (Samsung adaptive charger for example) power supplies provided more than 5.0V and did not work. When I used the better quality power supplies, the watch goes on a charge, but then in a second or so, stop charging. So play around with the power supplies.
I have marked the polarity on the printed adapter. + & -