Tuesday, September 2, 2008

28, Trolley drive.

The trolley drive mechanism mounted below the floor level.
I connected a 1hp 180volt DC motor to the reduction gear box, this being housed in the brown case. A chain couples this to the shaft in the recess. This shaft, complete with pillow blocks and bearings set me back about $75.00 from a junk yard. The windlass, fitted to the near end, I fashioned from a 4 belt cast iron pulley.
Another product of my regular jaunts to the junk shops was set of odd clutch set-ups, possibly off a shearing machine, picked up for about $10.00. These I re hashed to produce the pair of guide pulleys.
To prevent the overrun of the trolley I installed 3 limit switches to the rails, one at each end and an intermediate one that can be bypassed to prevent the roller door from impact.

The cable return pulley. I fabricated this assembly from scratch, adapting the sheaves from an odd pair that I had floating around.
The trolley has a central arm projecting down into the groove in the floor, the cables are hooked under this before rising to be secured at each end. I fitted a turnbuckle at one end, but this proved inadequate, requiring a tension spring to be added.

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