PlaneWave CDK14 Astrograph f/7.2: With the CDK 14", Planewave presents an astrograph with quartz glass optics
- modified according to Dall-Kirkham, with a fully corrected image field with a diameter of 70 millimetres
- 3" prism rail
- Hedrick focuser and EFA kit available separately, prepared for Delta T heater
The CDK optical design
The PlaneWave CDK layout is an optical design based on the classic Cassegrain design by Dall-Kirkham.
It was developed to accommodate the ever-increasing size of chips in digital and CCD cameras. With many other mirror optics, you quickly see off-axis aberrations such as coma and/or astigmatism; in addition, many systems suffer from image field curvature, which causes the images of stars to become increasingly blurred as they move away from the optical axis.
The image field is free of coma and astigmatism. In addition, the image field plane is absolutely flat and level across this diameter, so that stars are reproduced with the same sharpness across the entire field in the focal plane.
The CDK design offers a perfect solution to the problems mentioned above, with an excellent price-performance ratio and moderate delivery times.
It consists of:
- an elliptically curved primary mirror
- a spherical secondary mirror
- and a 2-lens field corrector
All three optical elements are perfectly matched to each other to achieve the incredible image quality. The image quality is largely dependent on the seeing conditions at the location.
The quartz glass (fused silica) used is a synthetic amorphous quartz glass of the highest purity and one of the most transparent glasses available. Due to its purity, the optical and thermal properties of quartz glass are superior to other types of glass. Its transmission and homogeneity exceed those of crystalline quartz and avoid the problems of temperature instability that crystalline quartz glasses suffer from.
Fused silica has a thermal expansion coefficient six times lower than that of borosilicate glass (Pyrex). It therefore retains its shape with a very high degree of accuracy when it cools. This results in consistent optical performance and an unchanged focal point during temperature changes.
L-Series Direct Drive Mounts
The L-Series combines versatility, simplicity and affordability by packaging proven technology, such as the CDK700 and the 1-metre PW 1000 telescope used in universities around the world, into a compact, stand-alone mount.
- The L-350, with a payload of over 45 kg, is ideal for the CDK14 and CDK12.5.
- The L-500, with a payload of over 90 kg, is ideal for the CDK17 and CDK20.
- The L-600 carries up to 136 kg and is ideal for the CDK24.
The mount is equipped with direct drives and high-precision encoders. The software is fully ASCOM-compatible and allows precise positioning and satellite tracking.
In Alt / Azimuth configuration, it is much more compact than a parallactic mount. This allows the movement radius of a larger telescope to be much smaller. This means that large instruments can be housed in small protective structures, saving a lot of money on the dome or building. Unlike parallactic mounts, there are no meridian flips and no large, protruding counterweights. The Alt/Az mode is more intuitive to use and there is no need for polar alignment.
- Motor: Direct drive 3-phase axial flux torque motors for azimuth and elevation
- Motor torque: approx. 20 ft-lbs continuous; 50 ft-lbs peak
- Encoder: built-in 152 mm disc in the azimuth and elevation axes with stainless steel encoder. Equivalent to approximately 0.069 arc seconds resolution
- Motor control system: Industry standard Parker brushless motor control and built-in electronics
- Power requirements: accepts 120 VAC. Supplied with regulated 12VDC 15A power pack
Scope of delivery:
- CDK 14 telescope
- Built-in heating elements to prevent condensation - The heating elements on the primary and secondary mirrors require the separately available Delta-T controller for PlaneWave telescopes with pre-installed wiring for the heating.
- OTA cover - To protect the primary mirror and the inside of the optical tube
- Flash drive - Contains software and instructions for collimation and primary-secondary mirror alignment
- Tool kit - Standard hex keys (only for orders from Europe)
- Soft cover for the secondary mirror
- 12V AC adaptors
- L-350 mount
- Six 3/8-16 x ¼" hexagon socket screws for screwing the mount to the column or equatorial wedges
- Six 3/8-16 x ¼" washers
- One extension bolt for the RA axis for polar alignment with the polar wedge
- EZ Saddle dovetail clamp
- The "EZ Saddle" 3" dovetail clamp accepts Losmandy D-series dovetail rails such as those on the CDK12.5 and CDK14. The clamp is included with the L-350 mount and can also be attached to the outer arm of any L-Series mount if the mount is to carry two telescopes.
- A 16' (4.8 m) USB cable – for connecting the mount to the observatory's control computer
- A 120V AC power cable – to power the mount
- A set of keys – for tightening the screws on the mount
- Flash drive – Contains the PWI4 software for controlling the mount and installation instructions
