K1RQG HYDRAULIC SYSTEM FOR ELEVATION CONTROL

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K1RQG HYDRAULIC SYSTEMFOR ELEVATION CONTROL
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SYSTEM COMPONENTS

• My system consists of a Power Pack (Motor, Pump,
  and reservoir as one unit)
• Two 40 inch hydraulic (two way) cylinders
• One control valve assembly
• Pressure switch
• Accumulator
• Two flow control valves, adjustable flow in one
  direction, full flow the other
• Pressure gauge
• External check valve (Power pack has internal
  one, but for maintenance)
• Return flow filter
• Contactor to run the motor
• This system can also be used to drive a hydraulic
  motor for azimuth control

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K1RQG HYDRAULIC SYSTEM CONTROL
SECOND CYLINDER IF USED CONNECTED WITH TEES TO 1
MOTOR CONTROL RELAY
PUMP
MOTOR SUPPLY VOLTAGE
MOTOR
RESERVIOR
PISTON
PISTON
HIGH PRESSURE
RELAY VOLTAGE
CHECK VALVE
FLOW CONTROL VALVE

PRESSURE SWITCH SET T0 1000 PSI
FILTER
UP
24 VDC SOLENOIDS PART OF CONTROL VALVE
DN
PISTON CONTROL VALVE COMPLETE
PRESSURE GAUGE
750 PSI NITROGEN
ACCUMULATOR
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Hydraulic schematic
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Construction Hints

• The complete hydraulic assembly is on a steel
  plate which bolts to the rotating part of
• the dish mount. This is 25 in the air and has 3
  eye bolts attached to allow for lowering
• it for major maintenance if needed.
• I piped the high pressure side of my system with
  ½ stainless steel pipe because it was
• available. You will need various adapters,
  reducers, plugs etc. I advise using swivel
• connectors wherever you can for ease of assembly
  and future service.
• All the hoses are locally made to length and are
  ¼ 5000 PSI rated. There is no need
• for anything larger as we are more interested in
  smooth slow operation. The cost is
• not much more than if ordered pre-made and makes
  for a much neater assembly.
• The accumulator is the key item that allows for
  slow smooth movement. This also
• minimizes the run time of the pump. During normal
  tracking of the moon, I have noted
• that it may be 10 minutes or more between run
  times for the pump.

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Construction Hints (cont)

• The accumulator works just like a water tank on a
  well system. It is pre-charged to a
• certain pressure with nitrogen (I chose 750 PSI)
  to operate the cylinders without
• calling for the pump to energize at every
  movement request. Your data may vary due
• to piston size and weight of your antenna system.
  
• I run the pressure at 1250 PSI max and it drops
  to about 1000 PSI before the pump
• starts and charges the accumulator back to 1250
  PSI.
• I use two flow control valves metered in one
  direction and full flow in the other for two
• reasons. One is the volume of fluid required to
  extend the cylinder is more than you need
• to retract it, and secondly, you can control for
  uneven weight distribution.
• To my knowledge, I am the only EME station using
  this particular method and so far, it
• has been trouble free and works excellent. I do
  leave power to the pump on 24/7.
• I do this to maintain constant pressure and
  assure no air gets into the loop.

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Important things to consider

• The accumulator listed here is NOT the same one I
  have. Mine is no
• longer available. There are many variations on
  the web page, and I
• urge you to be sure that the one you order has
  the right capacity to
• handle your project. Mine is approximately 2
  quarts. I do not have
• a good working knowledge, but I have been advised
  that one does
• not need a large volume accumulator to be
  functional. The main
• function is to maintain a relatively constant
  pressure and to absorb
• abrupt changes when the valves are actuated.
• Also, you do not need to purchase a Power Pack.
  You can assemble
• your own pump, motor, and reservoir to suit your
  needs. The one I
• have is set to bypass at 2000 PSI.

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Part Numbers

• The following parts can be found at
  www.SurplusCenter.com
• Main control valve with 24 VDC solenoids 9-5679
• Two plugs needed 9-6408-12
• Flow control valves 2 ea 9-5300-25
• Check valve is your choice 9-1019-50
• Pressure gauge 21-1246-J
• Filter is your choice (I use a fuel flow filter)
• Hydraulic cylinder of your choice (I bought mine
  new to avoid leaks)
• These parts can be found at MSC
  www1.MSCDirect.com
• Pressure switch 56491152
• Accumulator 76133990 or similar. (See things to
  consider)
• This can be ordered at www.northerntool.com
• Power Pack 1530036

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Hydraulic assembly
Tee to second cylinder
Pressure gauge
Power Pack
Flow control
Accumulator
Main control valve
PLUGS
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Rams, control box reservoir
Tee to second cylinder
Added reservoir
Motor control box
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Motor Contactor Box