Printed in PLA on Wanhao Duplicator I3 with compensation for normal line thickness. You must calibrate your printer before printing the bottom, or it won't fit on your LEGO. Then measure to see if your settings need a modification to the inner and outer thickness to the model. Wait for the print to cool off and shrink, then use fine sandpaper until it fits with lego without seams. Make dents for fitting metal parts on the circuit-board, or the LED will tilt when screwed tight. Drag the soldering-iron quickly over layer lines to increase external layed adhesion where most force is applied from collisions. Ten light strokes per mm gives a round look on the corners. Be careful not to overheat any region connected to LEGO, because 20 micrometers off will make it too loose or tight. Attach the LED using two M2 screws of legth 4-10mm. The LEGO bottom is soldered with the flat side against the legs. Cables are attached around the M2 screws with contact against the conducting plates.