I have been following George Hart's creations for a while and am excited for the opening of the Museum of Mathematics later this year. This particular construction was based on Hart's work entitled "72 Pencils." Thanks to friend Pat Flynn for use of his photo at left.
As part of a visual example involving recursive functions (showing how one thing relies on another previous value), I created several cousins of Hart's design, using some accumulated pencils I had in my classroom from over-anticipating students needing to borrow them. They are shown in this short YouTube video I created:
As far as difficulty in completing this project, I would emphasize this project requires patience more than it requires skill. Band together enough pencils to satisfy one "axis" of the construction and begin creating another "axis" by inserting pencils through it, intersecting with the appropriate number of pencils between opposing axes.
Good luck. Please comment and let me know what you think.