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Telescope Optomechanical Support Diagram
Angular Deflection of Pad
When it was bent after a flight, the central ring of the telescope truss was found to be misaligned by 0.022 across it's 3.5 inch diameter, or by 0.36 degrees.
To straighten it out, the secondary was deflected by 0.50 inches. At a distance of 25", that is an angle of 1.15 degrees. Assume the secondary will move this far during flight and landing.
Angular Change of Pad Due to Mirror Translation
Assume the mirror translates sideways by 0.050 inches under side loads. How much will the normal to the surface change at 0.7071(14/2) inch radius? At a 5" radius, the angular change normal to the mirror's surface is 0.058 degrees. This is not a significant source of error. Set the design accomodation to +/- 3.25 degrees.
Required Pad Area
What area must the pad have in order to support the mirror under a 20 gravity load?
The mirror weight at 20 g's is pi(R*R - r*r)L*density. R=7", r=2", L=2.5", density of Pyrex is 0.0806lbs/in3, so weight is about 28.5 lbs. At 20 g's, this is 570 lbs. Each of the three pads then supports 190 lbs. If the pad is 0.5" in diameter, its area is 0.196 in2, and the unit stress on the pad is 969 lbs/in2. The compressive strength of Nylatron GS at 10% deflection is 12,000 psi. Therefore the pad stress at 0.5" diam. is 1/10 that at yield.
Compression of Pad
The modulus of Nylatron GS is 450,000 psi. The compression it will undergo at 20 g's is equal to
(Load)*(Thickness)/(Area)*(Modulus of Elasticity) = (190)*(0.040)/(0.196)*(450,000) = 0.000,086 inches.
Extreme ultraviolet to long wave infrared. Thirty-seven years.
EDM Technical Services has been designing precision optical systems and optomechanical systems, from the extreme ultraviolet to the long wave infrared, for over thirty-seven years. We have experience in the design, system analysis, and production of a wide variety of optical and optomechanical instruments. Our capabilities include optical design, optical thermal analysis, stray light analysis, and optical system tolerancing for production.
We are an optical engineering and optomechanical engineering consultancy. We can take a design from the customer's concept through production and delivery: optical design, system analysis, prints and RFQs, vendor selection, prototype build, and the test procedures and documentation needed for production manufacture.
Special emphasis is given to anticipating and solving problems before they reach production.
Software
The tools behind the work.
Optical design
Zemax
CAD
Solid Edge, KeyCreator, Rhino
Stray light analysis
FRED
FEA analysis
Femap with NX Nastran
CAM
NX CAM Pro