Here is my sketch:
The triangle ##abc## is arbitrary, the triangles ##acp##, ##abq##, and ##bcr## are equilateral with centroids ##m##, ##n##, and ##k##. I suspect that the triangle ##mnk## is equilateral. Here is my proof.
By the equation for centroids,
##3m=a+c+p##
##3n=a+q+b##
##3k=b+c+r##...