Background

While working at Crosstree, Inc., I was challenged with engineering a 6.5’ H x 6.5’ W x 1.5’ D steel frame and hinge for a 4500 lb concrete gate at a Chicago residence. The clients also requested a track mechanism to help control the momentum of the gate during operation.

The designer for this project was Wheeler Kearns Architects.

Design and Fabrication

I developed a pivot system using two brass journal bearings and a heavy duty cylindrical roller thrust bearing to carry the load of the concrete door. I used FEA to verify component strength.

I designed the passive momentum control system using a spring and an industrial grade ball transfer that would ride along a rolled stainless steel track. I calculated the required height deviation and slope of the track, along with the necessary spring force needed to support and slow down the swinging door.

Installation

The door installation went very smoothly, and the clients were pleased with the bearing system. They were so pleased, in fact, that they opted out of the track altogether. The spring mechanism was removed from the door following installation.