The K-20 Project - Design Specifications
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Design:
Kriege-style Truss Tube Newtonian Reflector
Limiting Stellar Mag.:
16.5*
Rayleigh Resolution Limit:
0.27 arcseconds*
Total Weight:
To Be Determined.  (~150 lbs)
Primary Mirror:
20 inch Galaxy Optics "Premium Select"  See About The Optics for more information.
Coating:
96% Reflectivity Enhanced Aluminum, 3 Dielectric Layers over Al with a top sealing layer of pure quartz.
Focal Ratio:
f/5
Focal Length:
100 inches
Mirror Cell:
18 point flotation system with open tailgate for uniform support and maximum air circulation for rapid temperature equalizing.
Secondary Mirror:
3.1 inch m.a. with 98% Reflectivity Enhanced Aluminum, 5 Dielectric Layers over Al with a top sealing layer of pure quartz.
Secondary Spider/Holder:
Protostar spider with 4 ultra-thin stainless steel vanes and constant tension clutch plate collimation, NO LOCKING SCREWS!
Focuser:
2 inch JMI DX-1 Next Generation Focuser (NGF).  Dual Speed, low profile, high pressure steel on steel Crayford drive design.
Secondary Cage:
25.5 inch diameter, 12 inch height.  Weight To Be Determined.  (~12 lbs)
Truss Tube:
8-1.25 inch diameter poles.  Length To Be Determined.  (~5.8 feet)
Mirror Box:
11 Ply Hardwood Core, Hardwood Veneer Baltic Birch Plywood. Final dimensions To Be Determined.  (~ 29 x 29 x 25 inches)
Altitude Bearings:
26 inch diameter (1/2 circle only) cast Aluminum bearings.  Ebony Star Formica with Virgin Teflon pads at 15 psi
Azimuth Bearing:
Glassboard with Virgin Teflon pads at 12 psi
Digital Setting Circles:
Sky Commander XP-4 with 4000 step encoders
Visual Finders:
Telrad and a Meade 8x50mm S-T Viewfinder (best balance between light grasp, FOV and weight)
* = Under Ideal Skies

 


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