Dialing in print-in-place joints
What I learned tuning 24 articulated joints so they flex straight off the build plate — and the clearance numbers that actually work.
Print-in-place joints live or die by clearance. Too tight and the joint fuses into a very disappointing sculpture; too loose and it flops around like a wet noodle.
After a dozen test prints for the articulated dragon, I landed on 0.5mm radial clearance for FDM at 0.2mm layers, with a 0.3mm vertical gap. Below that, most printers weld the joint shut. The other trick: orient the joint axis vertically whenever you can — the seam hides in the layer lines and the joint breaks free with a satisfying crack on the first flex.
If you’re designing your own, print a single joint as a torture test before committing to the full model. Ask me how I know.