BRORFELDE SCHMIDT TELESCOPE
Designed and constructed at the Observatory Workshop.
Ready for use in August 1966.
Mecanical and optical main specification.
by Karl A. Augustesen, January 1995
Ready for use in August 1966.
Mecanical and optical main specification.
Weight 157 kg Diameter 770 mm Thickness 140 mm Center hole 130 mm Radius of curvature 3003.0 mm Focal length 1503.5 mm Image scale 137.2 "/mm
Weight 11 kg Diameter 540 mm Diameter with diaphragm 450 mm Thickness 20 mm
Kodak KAF 4201, format: 2048 x 2048 pix Pixel size 9 my x 9 my Spatial sampling 1.24 "/pix Field size 42' x 42' Cooled to -30 C Evacuated to 10-4 mbar Read-out noise 8.5 electrons Conversion factor 1.4 electrons/ADU Filters: B-V-R-I and open Filter dimentions 25 x 25 mm Rotating shutter with Exposuretimes: 0.1 - 9999 sec
Focus found in Feb. 93 (at -3 C) - 0.30 mm Focus should without filter be - 1.67 mm
Weight 64 kg
Objective prism 15 deg.2'
Diameter 500 mm
Thickness max. 149 mm
Thickness min. 15 mm
Mounted with max. thickness down,
when pointing south.
Offset at 4050Å 9 deg. 53' Disp. at 8000Å 735Å/mm
4350Å 9 deg. 45' 7000Å 530Å/mm
4800Å 9 deg. 37' H-a. 400Å/mm
5450Å 9 deg. 29' 6000Å 290Å/mm
6450Å 9 deg. 21' 5000Å 165Å/mm
7050Å 9 deg. 18' H 102Å/mm
4000Å 74Å/mm
Thread (nylon) 0.6 mm Space between threads 0.6 mm
Free opening 220 mm Focal length 2750 mm
Sanyo LC 9913 frame trans. CCD (shutterless operation) Format incl. overscan 600 x 300 pix Pixel size 15 my x 22 my Field size 11'.25 x 8'.25 Electrical 1 step peltier and water cooled to - 40 C The guide CCD will soon get a motor driven offset function which allowes guidestars to have a dist. from field center in R.A. and Declination. 30'
Free opening 100 mm Focal lenght 1000 mm Field diameter 45'
Weight (including mirror) 3000 kg Lenght incl. baffle 4000 mm Largest diameter 1010 mm Cylindrical part 2 x 8 mm ironplate with ribs Conical part 2 x 3 mm ironplate with ribs
Weight 1135 kg Welded together of 20 mm ironplate, and reinforced inside by ribs. Secured on polar axis with 16 20 mm screws. Carrying capacity 24000 kg
Weight 400 kg Conical tube made of 20 mm iron plate, and with a solid blank welded on each end for mont. of ballbearings and wormwheel.
Weight 1500 kg Constructed of 13 - 16 and 25 mm ironplate with inside reinforcements. Turn out in both ends for ballbearings.
Upper carrying bearing is a double roned angular contactballbearing with a split outer ring. SKF 234126 MB Outside dimensions 620x500x90 mm Balls 2 x 54 pcs 25.4 mm Lower bearing is a single roned guide ballbearing SKF 6040 M/C 15 Outside dimensions 310x200x51 mm
Bearingshousing of casted iron with turn out for ballbearings. The steelaxis are mounted on cyl. part of tube with 10 pcs 20mm screws The houses are monted on fork with 6 screws in each. The 2 x 2 bearings are single roned angular contactbearings O mounted. 2 SKF 7218BG outside dimensions 160x90x30 mm 2 SKF 7219BG outside dimensions 170x95x32 mm
Weight 165 kg Rademakers steel worm carried by 2 ballbearings. Rademaker bronzewheel Number of teeth 450 Modul 2.5 Outside diameter 1138 mm Wheelhup of casted iron Tolerances from tooth to tooth, less than 3 my
Weight 162 kg Rademakers steelworm, carried by 2 springloaded ballbearings Rademakers bronzewheel Number of teeth 360 Modul 2.5 Outside diameter 913 mm Tolerance from tooth to tooth, less than 6 my Both declination and polar axis have a mechanical preload to prevent backlash between worm and wormwheel.
Weight 600 kg Welded together of ironplate, and mounted to cyl. part of tube with 15 pcs 20 mm bolts The weight of the mirror is carried by 9 counterweights. The weight of the mirror in radial direcktion is carried by 15 counterweights and kept by a centerstear The CCD is kept in a constant distance from the mirror by 3 Invarlevers.
The mirror is covered, when serviced, or out of use, by a gearmotor driven segment cover. The cover is controlled by a handcontact placed in the dome.
The CCD camera is carried by a cross of 4 pcs of 8 mm alu. plates. The camera can be focussed by a motor which alloved a movement of 20 mm The position can bee read, and controlled on a box placed on the mirror cell. Reading accuracy 0.01 mm Speed 0.05 mm/sec
The CCD chip is kept in a alu. vacuum chamber, which can bee evacuated to 5 x 10 -4 bar by a Alcatel vacuum pump type Drytel 25 The chip is cooled by a 3 step peltier, and the back of the peltier is cooled by water circulated and cooled via a radiator in the basement. In front of the chip there is an optical window, a motordriven shutter and filterwheel.
Welded together in ironplate, and bolted to the conical part of the tube. The corrector is kept in radial direction by 6 springloaded pins, and axial supported and fastned by 6 bolts.
Welded together of ironplate, and bolted to correctorsocket. The prism can be mounted in 4 positions. The prism is kept in radial direction by 9 springloaded supports, and axial supported of 2 x 3 adjustbar bearingpoints. The prism (incl. socket) must be replaced by a counterweight when not used.
Ra and Dec. are both supplied with identical drive systems. Motors: Ahsthona Parvex type T4C3B, direct driving on worm. 10 bit Leine & Linde model 73 absolut encoder on main axes, to define which tooth is engaged on wormwheel. 17 bit Heidenhein type Roc 717 absolut encoder to subdivision of tooth. Axiel compensator to transmit effect from motor to worm. Local moment of inertia direct on motoraxis. Upgeared inertimoment with gear direct on motor to protect worm and wormwheel against overload in a emergency situation.
Total weight of the telescope 8000 kg Total weight of movable parts 5500 kg
T-C-S Telescope Control System is operated by a IBM PC computer. The Science CCD camera is controlled by a PC computer, using LINUX and BIAS programs The observations can be transmitted directly from the Winner to the observatory HP Apollo workstation via ethernet. The Guide CCD camera is operated with a PC computer.
Building outside diameter 780 cm Inside diameter 680 cm Thickness of walls 50 cm Height of basement 220 cm Height of building 820 cm The underpart is made of concrete, covered with granite, and with a gap between building and telescope foundation.
Weight of movable parts 7400 kg The dome is made as a latticework coverd outside with 2.5 mm ironplate and inside with 2 mm plate. Airgap betveen plates 20 cm The dome is rotated by 2 Cebeha gearmotors type CB 33 6c, each on 1.5 HP The dome rotates one rev. in about 86 sec The dome rotation can be "connected" to the telescope movement via a dome encoder and TCS system The obs. doors give a free opening width 162 cm They open by a STRONG gearmotor type SA 1 1.5 Hp They open within about 40 sec Weight of each door 940 kg
Weight of telescope concrete basement 50.000 kg Hight over floorlevel 212 cm Width 190 cm Lenght N-S 250 cm Depth below floorlevel 250 cm Total height 462 cm
Last updated June 23, 2000 by norup@astro.ku.dk. Original page design: MYKAL.