Other printable drag chains were either too small for my work-in-progress CNC router or required superhuman bridging capabilities from your printer. This parametric model allows you to produce arbitrarily-large drag chain links, with the angled ‘roof’ eliminating the need for heavy bridging. Print individual links and easily assemble by hand, or print in place as long as your printbed will allow. The attached STL is for a single 15x20mm link, but edit the OpenSCAD file for arbitrary sizes and chain lengths. 

No supports required, prints fine without a brim on my machine - an easy-to-print, effective model.