article_snippet: Black Butterfly weighs 2kg and the wheels make up almost 30 per cent of that weight.
article_snippet: With Alison wheels attached Black Butterfly is able to gingerly walk on Alison two front legs and after a few steps will stop for a rest before starting over again .
article_snippet: Claire is concerned that the mechanical wheels for Black Butterfly are too heavy and the length is not suitable and needs to be fixed.