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Planewave CDK400 Observatory System

SKU 170130Q
Original price $44,500.00 - Original price $44,500.00
Original price
$44,500.00 - $44,500.00
Current price $44,500.00

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Enjoy exceptional optical and tracking performance for astrophotography, or research, with the CDK400 package! Includes a CDK17 optical tube and L-500 mount.

The PlaneWave Instruments CDK17 is a 17 inch (0.43 m) f/6.8 Corrected Dall-Kirkham Astrograph telescope. The CDK17 has a dual carbon-fiber truss design, with 3 cooling fans ejecting air from the back of the telescope, and 4 fans blowing across the boundary layer of the mirror's surface. The CDK17 covers a 70 mm field of view without any field curvature, off-axis coma, or astigmatism. The instrument weight is 94 lbs (43 kg) and comes standard with a backplate retaining ring ready to accept the focuser of your choice.

CDK17 optical tube:

  • f/6.8 and 2939mm focal length

  • No coma, no off-axis astigmatism, and no field curvature.

  • Pinpoint stars across a 70mm image circle.

  • Rock solid fused silica mirrors with low thermal expansion.

  • Carbon fiber optical tube assembly for rigidity and fast cooling.

  • Simple secondary mirror collimation thanks to the fixed primary mirror.

L-500 direct drive mount:

  • Zero periodic error, zero backlash, and minimal maintenance due to the lack of gears.

  • Slew speeds up to 50 degrees/sec for satellite tracking and fast target acquisition.

  • Sidereal tracking accuracy of < 0.30 arcseconds RMS over 5 minutes.

  • High resolution optical encoders on both axes for precision feedback.

  • Can be installed in either equatorial, or alt/az configuration.

  • Includes PWI4 software (ASCOM compliant) for mount control.

    All CDK17 telescopes come with fused silica primary and secondary mirrors. 

    The L-Series combines versatility, simplicity and affordability by combining all the technology of our Observatory class telescopes into a compact stand-alone mount.   In its Alt/Az configuration, it is considerably more compact than its equatorial counterpart, allowing a larger telescope to fit in a smaller enclosure. The mass it takes to make a rigid alt/az mount is substantially less, leading to cost savings. Unlike German Equatorial mounts, there are no meridian flips to deal with, and no  large protruding counterweights to create a dangerous hazard in a public observatory. Alt/Az is more intuitive to use and no polar alignment is needed. Besides, it is the way the pros do it!

    L-Series Mount Features
    • Direct-drive motors on each axis for smooth, fast, and virtually silent movement of the telescope

    • Slew speeds up to 50 degrees per second

    • High-resolution encoders on each axis for precise positioning

    • Zero backlash

    • Zero periodic error

    • PointXP mount modelling software

    • Enclosed electronics

    • Through the mount cabling

    Direct drive motors and encoders

    Direct Drive motors and on-axis encoders eliminate the need for  gears, thereby eliminating backlash and periodic error. With high-resolution encoders providing the feedback for the direct drive motors, not only will the telescope track without periodic error and backlash, the mount will also counter wind gusts with precise servo feedback.  

    Incredible Slew Speed

    The direct drive motors can move the telescope at speeds up to 50 degrees per second for tracking satellites or just to minimize target acquisition time.  

    Dual mounting bracket

    PlaneWave style mounting bracket to hold CDK17/20 onto inside of fork arm with additional option of mounting a scope on the outside of the fork arm. Optional dovetail clamp required.  

    Azimuth dovetail balance system

    For precise center of gravity balance whether in Alt-Az or Equatorial configuration  

    Through the mount cabling

    Access panels in the fork arm and azimuth axis allow for camera equipment cabling through the inside of the mount.  

    Proven CDK700/PW1000 Technology

    The L-Series uses the same proven technology as the CDK700 and 1-Meter PW1000 which are being used in Universities round the world.  

    CDK-400 + Core Accessories

    Item Number



    170130Q CDK-400 (CDK17 / L-500) $37,000
    600180 IRF90 Rotating Focuser $  4,500
    240901 EFA, Focuser Accessory Control $  1,000
    Total $42,500

    Mount System

    Type Alt-Azimuth / Equatorial Direct Drive Mount
    Weight 257 lbs (100 kg)
    Component Weights Azimuth Base – 121 lbs, Fork Arm – 136 lbs
    Max. Load Capacity 200 lbs (91 kg)
    Latitude Range 0 to 90 degrees, Northern and Southern hemispheres
    Cable Management Equipment cables can be wired through mount

    Control System

    Control Electronics PlaneWave Interface dual axis telescope control
    User Interface PlaneWave Interface 4 (PWI4) Control Software with integrated PointXP mount modeling software
    Homing Sensors Home position sensors are included allowing the mount can find its home position on power up.
    Slew Rate 20 degrees per second (standard); 50 degrees per second (maximum), both axes
    Power Requirement Accepts 120 VAC. Supplied with 12VDC 15A Regulated Power Adapter

    Optical System

    Aperture 17 inch (432 mm)
    Focal Length 2939 mm (115.71 inch)
    Focal ratio F/6.8
    Central Obstruction 23.7% by surface area; 48.6% of the Primary Mirror Diameter
    Back Focus from Mounting Surface 10.24 inch (260 mm)
    Weight 106 lbs (48 kg)
    Optimal Field of View 70mm Image Circle

    Motion Control

    Motor Control Industrial grade brushless motor control system and built in electronics
    Motor – Azimuth and Altitude Direct Drive 3 Phase Axial-Flux Torque Motors
    Encoder – Azimuth and Altitude 152mm stainless steel encoder ring with reader built into the azimuth and altitude axes. 18,880,000 counts per revolution (0.069 arcsecond resolution).
    Motor Torque Approximately 20 ft-lbs continuous; 50 ft-lbs peak
    Drive Electronics Industrial grade, off-the-shelf brushless motor drives for each axis with custom designed interface card
    Telescope Control Software PlaneWave Interface (PWI4). Incorporates PointXP mount modeling software by Dave Rowe. Provides HTTP and ASCOM control interfaces.

    System Performance

    Pointing Accuracy <10 arcsecond RMS with PointXP Model
    Pointing Precision

    2 arcseconds at sidereal velocity

    Tracking Accuracy

    < 0.3 arcseconds over a 5 minute period at sidereal velocity

    System Natural Frequency 10 Hz or greater

    L-500 Pier Interface Drawing

    L-500 Mount Dimensions

    L500/600 Mount Instructions

    PlaneWave Interface 4 Software User Manual_V15 1.7.2021

    Included Items
    Heating elements for dew prevention The heating pads on the primary and secondary mirror require the 600195 Delta-T controller sold separately
    OTA Cover To protect the primary mirror and inside of the optical tube
    Flashdrive Contains software and instructions for collimation and spacing the primary to secondary mirror
    Hardware Six 1/2-13 x 1 1/4″ socket head cap screws to bolt the mount to the pier, or wedge


    Six 1/2-13 washers

    One extended length shoulder bolt for RA axis to EQ wedge alignment

    One 16′ USB cable To connect the mount to the observatory control computer
    One 120VAC power cable To provide power to the mount
    Standard Allen Key set For tightening bolts used on the mount
    Flashdrive Contains PWI4 software for mount control and instructions for installation
    Gamepad Used for control of the mount tracking speeds for visual observing
    Recommended Accessories

    Reducer .66x CDK17 (125166)

    Mounting Bracket for Finderscopes (125360)

    Finderscope and Mounting Bracket (200985)

    Visual Adapter – CDK17 (200399)

    Delta T Heater Part (600195)

    Hendrick Focuser (200340)

    IRF90 – Integrated Rotating Focuser (600180)

    EFA kit Electronic Focuser (240901)

    Light Shroud CDK17 (170970)

    Dovetail Clamp CDK17 (200919)

    Piggyback Dovetail Bars (170991)

    Portable Rolling for Pier Mounts (600128)

    Equatorial Wedge, L-500/L-600 Mount (600560)