After the first round of engineering there still remained a lot of questions about the feasibility of mobile elliptical. Stationary also had some implementation questions involving interaction with stationary trainer. I networked around and found former engineers from the Rehabilitation Institute of Chicago. We established a working relationship and started digging into the problems/challenges.

First we established a custom trainer was necessary to make sure stationary elliptical would work universally (trainers liked wahoo kickr work out of box but they may be seen as prohibitively expensive). We based our new design off of slocum bicycle trainer (http://www.hscycle.com/Pages/slocumtrainers.html) as that design seems most stable independent of direction of forces exerted). We adjusted rear arms to create narrow central profile to allow clearance for ellipses travel through space