The ASA Direct Drive Mount 85 (ASA DDM85XL) is a robotic high-end mount, which can be operated without conventional guiding controls due to its high accuracy. The high resolution, Renishaw Encoders are mounted directly on the axes of the Direct Drive Mount 85, so even wind gusts can be compensated for easily. These encoders are verified electronically and resolve to an unbelievable 0.01-0.02 seconds of arc.
Positioning information is communicated by Autoslew software developed by Philipp Keller. The tracking accuracy is accomplished by comparing the actual position of the system 100 times per second in real time. This permits any required corrections to be applied immediately. The software eliminates all reproducible errors such as collimation, backlash, slippage, refraction, precision, etc. The theoretical resolution of the encoders is 0.02”. By using appropriate pointing files a tracking precision of 0.25” RMS for exposure times of up to 5 min. (0.40” RMS for 10-15 min. exposure time) can be achieved. Furthermore, GOTO positioning of 5 to 10 arc-seconds accuracy can be achieved by the use of pointing-files as well. There is no backlash and no periodic error. Most professional observatories are based on this technology.
|Name||ASA - DDM85 Standard - Direct Drive Mount|
|Manufacturer||ASA - Astrosysteme Austria|
|Bearings||Preloaded taper roller bearings 130/85 mm|
|Counterweights||High-grade steel 5 kg, 160 mm|
|Diameter||Diameter of the axis: RA/Dec. 85 mm hollow axle|
|Motor Drive||High torque motors in RA and Dec. (Direct Drive without gear)|
|Payload Capacity||Approx. 220 pounds (100 kg)|
|Power Supply||12V/<10 A (0,4 - 0,8 A/Tracking)|
|Tracking Rates||< 0.25” RMS in 5 minutes|