using fusion 360
-Draw circiles that spacifies the general shape of the spinner and with a diameter equal to the bearings' diameter. Draw bigger circles that would be the body of the spinner. Make 3 tangent lines to the 3 big circles.In the mid point of the tanget lines make a circle tangent to the two circles that are at the end of the tangent line. Then trim what is extra. Insert the bearings from the store and make 3 copiees of it and join them to the holes
After saving the design as STL, we took the file to the makerbot system to specify the printing features and know number of grams and the required time to finish the part.
It was required 16 gm to print this spinner in 1 hour and 14 minute.
note: i used makebot printer but the following screenshoot from cura software as i don't have makerbot sofware. However,It is very close to the result that i got from makerbot software.