Today, we finished putting together the assembly with the parallel soft bungee cord (parallel to the chain). See 2013.06.03 System Setup Diagram.png. Note that the bungee assembly that was previously inside the top bar (that the seat slides on) was taken out in order to make further adjustments easier. To do this, we secured the 2 ends of the bungees and chains and allowed the middle to hang loose. However, we didn't want the middle to be so loose such that it would drag on the floor. To prevent this, we flanked both sides of the bungees with pieces of cardboard. The cardboard pieces allowed enough room for movement, but not enough for the cords to slide through. See Figure 1.
Figure 1: Parallel soft bungee assembly, closeup.
Figure 2: Entire erg assembly as of Wed 5 June 2013.
We also made a visit to Teagle and convinced the rowing coaches to allow us to try out their ergs on slides. While we were there, we met William Tyler Nebel, a guy on the Cornell Men's Rowing team, who agreed to let us film him while he rowed. We noticed that the rower's body and the COM hardly moves while rowing on the ergs on slides. That is the problem with the erg on slides. We were also referred to Christopher J. Kerber, the Men's Lightweight Rowing coach, who is reputed to have a lot of data on rowing. We plan on contacting him sometime during our further research on the physics of rowing.