• Gen 2 - Chain Drive

    Drew Shelley08/10/2014 at 04:34 0 comments

    We set out to redesign the walker. My dad had some Harken travelers from a sailboat to use as the track and linear bearings. I found a power window motor and ordered some XL timing belts, pulleys and bearings from McMaster Carr. We built the walker with one motor driving both pulleys and belts to lift the handlebars. But the timing belts kept slipping. Also, the quarter inch driveshaft was too flimsy. We changed the design and switched out the timing belts for a chain drive and larger drive shaft.  Then finally it worked!

    But this design has a fatal flaw: If the chain breaks, the whole thing will collapse. I needed something better. 

  • Gen 1 - Mini Track Actuators

    Drew Shelley08/10/2014 at 04:24 0 comments

    Last year we built this super walker with Mini Track Actuators from Firgelli Automations.


    It worked great at first. I could sit and stand anywhere. We even built a second walker with the same mini track actuators. 

    But those little actuators just weren't up for the challenge. They kept binding from the leverage on the carriages. One was always faster than the other because there were 2 separate motors with no synchronization. Plus the little motors were too delicate and kept burning out. In the end, 3 out of the 4 actuators failed.