Classic Erector set to LEGO (with lego tools) in OpenSCAD

thingiverse

My grandson is a great LEGO builder, but now I am giving him a classic Erector Set to expand his abilities. Along with it, I thought we could create a set of transition pieces that would allow mixing the two. I started with the library contained in http://www.thingiverse.com/thing:13531/#files but modified it. Read the instructions to see how to make the parts shown -- a connector from the LEGO block to a classic square girder, a connection from the square girder to the LEGO blocks, and a flat plate to screw on the top of an Erector plate. Instructions Three files are needed for the SCAD program, lego.scad, lego_dimens.scad, and ErectorToLego.scad. lego.scad contains the modules that are used in building LEGO blocks, lego_dimens.scad is the source of the basic LEGO dimensions and may need to be modified slightly for your printer. The main build of the parts is in ErectorToLego.scad. The main things you may want to change in building the pieces are the number of "knobs" in width and length and the thickness of the pieces. There are three primary modules in the file -- one to create the transition from LEGO to Erector (Top_Er), one for the transition from Erector to LEGO (Bottom_Er) and one to make flat plates with screw holes (Er_plate). The first three parameters in each are the number of knobs wide, then long, then the thickness. An additional parameter in Top_Er specifies whether reinforcement will be added inside the bottom of the block. In Bottom_Er and Er_plate parameters allow an extension of the knobs (in mm) and creating a chamfer on the knobs. This may allow a better fit for these pieces. In Er_plate, the span_holes parameter sets how many holes are spanned (inclusive of the end holes) for the screw holes through the Erector plate. The modules provided should be useful for other transition peices, either to Erector sets or to other construction sets.