Tealight holder add-on

This is a tealight holder add-on which can be merged to other models/objects. It is compatible with a small cheap chineese tealight with bottom size (diameter) 38mm, 37mm at the top, base height 20mm. The tealight is simply snaps into a holder add-on. The cover shows an earlier version of the add-on. The final release can be seen merged in tealight cup.

I also published a Fusion360 file so you can change the model for compatibility with other tealights. 

Possibly the easiest way to merge it to other models is to use Tinkercad instead of Fusion360. Keep in mind that Tinkercad has a restriction in 300000 polygons for imported models. If the model is not extremely complex the amount of polygons can be reduced in Fusion360 without a significant loss. The example of such a merge can be found here.

 https://www.printables.com/model/845685-tealight-cupholder-easter-egg-remix

Another way to merge can be opening both model and tealight addon files directly in slicing program. I made several trials in Cura 5.7 but did not find a correct way to slice both models as a single object. There are some options in Cura which supposed to merge and slice objects so the printer would print them as a single model, but instead it was printing the bottom layer of the add-on first and the bottom layer of the main model extruding filament twice in intersecting areas. The final result was fine, but in some single trials this led to shifting model on the table when the nozzle was extruding over the previously printed add-on part. I am not sure if I set all the options correctly and if this is not a feature of the Cura. I would appreciate if some of you find and share the way to merge it directly in the slicer.