Making a chain with changing size I want to make a chain with an increasing thickness or a increasing size.

Increasing thickness would be better, but a changing size is also okay because it effects also the thickness.

What I have so far is a closed curve with an array which follows a helix spline.

The helix spline is needed because I want to print a rather long chain (800mm).
All what is needed is an Array Modifiyer and an empty.



Add an array modifier to the oject. 
Add an empty to the scene at the red dot.
Scale and rotate the empty slightly. Thats to get a spiral and a decreasing size.



Adjust the fine tuning with the relative distance. (Y und X values in my case).



If the empty is rotated, it creats a chain ring.
If you want to print it: move the empty downwards, until all segments ar on the same hight.

Also there is an advantage because there is no curve modifier wich deformes the single sements of the chain.