Intro: 3D Printing a Cabbage Moth / Butterfly Decoy to Save Your Cabbage
Perhaps you’re a gardener and have seen these white little butterflies (Cabbage Moth / Cabbage Butterfly Plutella xylostella, Pieris rapae) that lay eggs on cabbage, then the hatched caterpillars devour your vegetables. It is referred to as both a moth and butterfly. It turns out these little delicate insects are highly territorial and wont go into a garden area where another is.
Old remedies were to spray tons of chemicals all over everything, spread egg shells in your garden, or place white paper butterfly decoys - but now we have 3D printing.
So I designed a 3D cabbage butterfly in AutoCAD and used STLOUT or 3DPRINT command to generate a STL file for use by 3D printers. I could also have easily designed the 3D Butterfly and generated an STL 3D Print export using the free Autodesk 123D solid modeling software. I then printed it on my MakerBot Replicator and then affixed it with fishing line to some 1/8” copper wire.
It will now fend off any other cabbage butterflies in the garden.
Step 1: Materials Required
A CAD software than can create 3D and then create a 3D solid part in STL format like AutoCAD, Inventor Fusion, or the free Autodesk 123D.
Acetone to smooth the completed ABS plastic or chemically weld the antennae to body of butterfly (optional) You could also use a hot glue gun as an alternative.
Black magic marker to add black dots to the final 3D printed butterfly
3 feet of 1/8 inch copper wire available at Home Depot and other home supply stores.
8 inches of fine fishing line
Step 2: Draw a Butterfly in 2D to Build the 3D Print
I inserted an image of the cabbage butterfly in AutoCAD to make sure I created an accurate representation of this butterfly even the size which is roughly one inch. I then use splines to trace the shape and then mirror it as there is no logical reason to draw two sides of something that is symmetrical.
Step 3: Make It 3D
In any application that supports 3D, you can extrude 2D entity into a 3D solid. I extruded the z-axis to .125 inch to give it thickness enough that it can be 3D printed and also keep the wings from deforming during the printing. In AutoCAD and used STLOUT or 3DPRINT command to generate a STL file for use by 3D printers
Export the 3D solid as a STL file which is what 3D printers use as the basis to print in 3D material.
I published the 2D DWG and 3D STL files on Thingiverse. at http://www.thingiverse.com/thing:26719
Step 4: Make a Physical 3D Print
I am using a MakerBot Replicator which is a consumer model 3D Printer. It can print in ABS plastic which is the same material as Legos. There are online 3D Printing services like Shapeways.com for those that do not have access to a 3D printer.
I import the STL file and in the Replicator-G software prepare the 3D object for generating G-Code machine language for the 3D printer to then print and create our physical 3D model of a cabbage butterfly.
Step 5: 3D Print and Clean Up
I used white ABS as well as some pink for my daughter and a few glow in the dark ABS materials.
Once printed you can use acetone to clean up rough edges or an exacto knife. After cleaning up use some sandpaper to roughen the surface to a matte finish.
Step 6: Final Assembly
Now cut some small scrap ABS typically ejected from the 3D printer when you start printing. Cut two 3/4 inch pieces and use acetone or hot glue to attach to the body section of the butterfly to be antennae.
Use a black marker to add a few black dots on the butterfly wings just like the real ones.
Glue the small piece of fishing line to the butterfly.
Now take the copper wire and bend the top into a loop and affix the fishing line to it.
Now place it in your garden to fend off cabbage butterflies / moths.