Jointed Snake

thingiverse

After seeing 4MULE8's wonderful sea turtle I knew I had to do something with ball joints. This snake is comprised of an arbitrary number of body segments, plus tail tip and head. Each segment is fitted with one or two ball joints that mate flush and allow limited movement. Currently only the body segment is available. Instructions As there is not a lot of contact between the model base and the build plate I recommend printing PLA directly onto an acrylic build plate. Prints just fine with standard settings (2 shells, 10% infill, 0.20mm layer height) in a little over an hour. Internal support structures are used to help ensure successful printing. These break away and are only evidenced by an initial slight grinding. In fact, the supports are so fragile that simply removing the model from the build plate breaks the lower joint free and the upper will break away with very little effort, if any. When planning for size note that the body length is about two inches per segment (they are slightly over 40mm, but the ball joints extend out enough to add the missing centimeter). The tail tip and head will be of similar length. Due to limitations of the interlock dimensions to get the body segment to this size required having the prongs go entirely through the ball socket. To allow this to work there is a cavity behind the lower ball socket to allow the prongs through. So to join two segments ensure the lower ball is oriented as it is when printed (the whole is completely vertical), squeeze the prongs together and push firmly. It will be fully engaged when the balls are flush. The sizing of the cavity behind the lower ball joint is a bit close so the prongs may contact the interior enough to grind a little at extremes.