This print requires a build plate with good adhesion. Make sure your plate is clean or use an adhesive. 

Smooth round chain is printed in place with minimal supports. The chain links are printed in a near-vertical position with a raft so that there are no flat surfaces on any of the links. The smaller chain has 25mm links and the larger chain has 50mm links. Separate print profiles are provided for the A1 Mini and for larger printers. Larger printers will make a longer length of chain. A single connector link is included in each profile for those who want to connect multiple chains together, or if you want to make a closed loop of chain.

For best results, ensure that you are using a dry, high-quality filament and that you have taken appropriate steps to maintain good adhesion to the build plate. Failure to do so could result in a failed print.  Build plate adhesion can be improved by washing the plate with soap and water, or washing the plate with alcohol, or by using a glue stick or a liquid glue on the build plate.