As of yesterday the "tower" of blocks is complete. The blocks seem to fall with good spacing and yet they still resemble a "tower" structure.
Cylindrical wooden dowels didn't provide the structural support I needed so I switched to furniture balusters which are much thicker. In the above photo you can see the beginnings of the pulley system that winds up the blocks into their "tower" form.
The above photos show that the wind-up pulley works and, once let go, it allows the blocks to fall in a smooth manner.
After getting instructor feedback, I'll be putting the final touches on the sculpture in preparation for Thursday's presentation.