..elevation control hydraulic system

...hydraulic system for elevation control is assembled and installed on the az-el mount. Hydraulic ram particulars are 4" bore, 16" stroke, 1.75" dia rod, 3,000 psi max working pressure. The pump can deliver 1.4 GPM at 880 psi (but it is operated at less than max flow rate); pump motor is 3/4 HP, 110 VAC. Hydraulic fluid reservoir capacity is 1 gallon. Reservoir is painted to help protect the plastic reservoir from solar ultra-violet radiation. The system includes a 110 VAC dual-solenoid, 4-way fluid valve to switch between up and down motions. The white PVC cross member is a temporary structure that simulates the dish mount connection for the ram to allow testing of the complete elevation control system including the hydraulic system and absolute elevation encoder using the controller board (from W2DRZ) and tracking software (from F1EHN) (March 2, 2005).

...connection detail of the hydraulic system. The (blue) 4-way valve, pressure gauge (1500 psi max, facing opposite here) and the elevation speed-control needle valve (top port of ram) are shown. A single needle valve restriction to the fluid flow at one port on the ram is used to control both up and down speed (March 2, 2005).

...4-way valve detail. High pressure fluid from the pump enters on the right, top connection is to the top of the ram, bottom connection is to the bottom of the ram, and the left connection is the return line to the pump. Electrical connections to the solenoids are shown (March 2, 2005).