layer .2mm nozzle .3mm no support needed reduction per element: 3.75:1, but it may be selected in .scad file advice: set "seam position" to random there are 3 clearance definitions in the .scad file: tol - clearance between gears dh - vertical clearance of rolls dd - horizontal

based on http://www.thingiverse.com/thing:53451

added slightly miniaturized version with: outer diameter of ring: 45 pressure angle: 20 helix_angle: 45

and smaller, with ratio 13:56, pitch 2.5mm added flywheel for the smallest one (should be printed with 100% infill)

added 40mm version nozzle .3mm, layer .15mm clearance set to .43mm, may be lowered on better printers