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Line 32: − + − + + − − ===Step Size=== − + − + − + + +
Calibration Device for Scintillators (view source)
Revision as of 18:15, 5 May 2011
, 18:15, 5 May 2011→Belt System
== Belt System ==
== Belt System ==
*Stepper motor with micro controller stands stationary on one end and calibration device would be connected to a slide rail system for stability[[File:Gears 01.gif|thumb|Clamping Plate Setup http://www.polytechdesign.com/images/gears_01.gif]]
*Stepper motor with micro controller stands stationary on one end and calibration device would be connected to a slide rail system for stability[[File:Gears 01.gif|thumb|Clamping Plate Setup http://www.polytechdesign.com/images/gears_01.gif]]
*We need to find something that is low cost but is accurate enough to be stopped at each fiber array block. Because the intended light source for calibration is most likely going to have a wide range, the step size does not have to be too small.
*We need to find something that is low cost but is accurate enough to be stopped at each fiber array block. Because the intended calibration source is most likely going to have a wide range, the step size does not have to be too small.
*For support: Overhead Enclosed-Track Conveyor Bracket, linear guide rail
*For support: Overhead Enclosed-Track Conveyor Bracket, linear guide rail
[[File:linear motion setup.png|thumb|Linear Motion Setup]]
[[File:linear motion setup.png|thumb|Linear Motion Setup]]
==== Beam Deflection ====
*The deflection at the center of the slide rail is calculated using a simply end supported beam as a model with beam deflection equations considering the weight of the bar and the weight of the cart. The maximum deflection was calculated as not exceeding 6um, well within the limit for our usage.
==== Motor ====
==== Motor ====
*LinEngineering 1.8 Degree Motor 'WO-5718X-05E' was found to be appropriate and cost effective. [http://www.linengineeringstore.com/products/part.aspx?partID=58]
*LinEngineering 1.8 Degree Motor 'WO-5718X-05E' was found to be appropriate and cost effective. [http://www.linengineeringstore.com/products/part.aspx?partID=58]
*With a LinEngineering 1.8 Degree Motor and a radius of .5" for the pulley, the step size would be 0.005" or 0.127mm which is well within a 2mm scintillator.
*With a LinEngineering 1.8 Degree Motor and a radius of .5" for the pulley, the step size would be 0.005" or 0.127mm which is well within a 2mm scintillator.
====Electronics====
===Beam Deflection===
*To operate the linear motion stage, a series of electronics is set up that works together to move the pulley system. First a computer program built with Labview was created to communicate with the Digital to Analog Controller(DAC) via USB. The DAC has pin-outs arranged similarly to a serial port, that control the driver. The R208 microstep driver has various wires connected to the DAC. When the circuits are opened and closed via the Labview program, the stepper motor steps forward or backward. From the driver, the 5V logic power wire is connected to the 5V output on the DAC and the 24V, 2 Amp power driver wire is connected to the power supply. The logic ground and power ground are also connected to the power supply ground. The stepper motor in use is a 1.8 degree high-torque model with a four wire connection.
*The deflection at the center of the slide rail is calculated using a simply end supported beam as a model with beam deflection equations considering the weight of the bar and the weight of the cart. The maximum deflection was calculated as not exceeding 6um, well within the limit for our usage.
*The user can select a left or right direction, how many steps per interval, the number of iterations and the time delay between iterations. The program tracks the current location of the rail carriage based on the number of degrees rotated.
====Structure====
*The main feature of the linear motion stage is the heavy duty optical rail the carriage moves along. Two pulley mounts designed in Turbocad and fabricated out of aluminum are used to hold up the pulleys and attach the stepper motor. The mounts are fasted to the optical rail using bolts attached to rail clamps. A belt is placed connecting the two pulleys and is tightened using the rail clamps on the optical bar. The rail carriage that will house the calibration source is attached to the belt via a metal clamp. The linear motion stage will not only be effective moving precision distances to calibrate the fiber array, but it is rigid enough to be used as a structural beam in the construction of the tagger microscope.
==To Do==
==To Do==