Present Manual Control System for Alcator C-Mod

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Present Manual Control System for Alcator C-Mod
MSE Shutter (Schematic)
frame supporting wheels
clamps to feedthroughs
Rotatable shutter (in vacuum)
conflats
rod
wire cable
Linear feedthrough A
stiff tube
Linear feedthrough B
wire cable
handle

• We want to rotate the shutter into one of three
  positions
• Position 1 linear feedthrough A almost fully
  in feedthrough B almost fully out.
• Position 2 linear feedthrough B almost fully
  out feedthrough B almost fully in.
• Position 3 linear feedthroughs A and B in an
  intermediate position.
• To ensure that all cables remain in a state of
  tension, the back ends of the two linear
  feedthroughs are
• connected with a restraining cable that loops
  around two wheels supported on fixed axles.
• Presently, we manually push and pull to
  position the shutter in the desired position.
• To ensure that the rotatable shutter is
  positioned properly, we need an accuracy of about
  2 millimeters on the
• position of each linear feedthrough.
• The system of wire cables that controls the
  movement of the rotatable shutter is pretty
  stiff. I estimate that about
• 5-10 pounds of force are required to move
  them.
• If we pull too far in one direction, we will
  probably break the connection between the
  internal wire cable and the
• shutter. So we to provide for stops that
  limit the push-pull of both linear feedthroughs.

restraining cable
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Proposal 1 for Remote MSE Shutter Control
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Remote MSE Shutter Control
Optical slot switches (TBD)
14CCF series Berg Cable chain 0.1475 pitch
Linear feedthrough A
2.5
Linear feedthrough B
1.0-1.75 diameter Berg chain sprocket
Berg chain sprocket (Size to match existing
wheels)
Need to figure out means of connection to linear
feedthrough
Need belt tensioner?
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Schematic of Stepper Motor Control System
Chain sprocket
shaft
Stepper motor
Supporting Frame
Torque limiters (2) Are these needed?
motor drive electronics
optical switch outputs
?
power supply
PLC