Robotic Mounting


TMB 152/1200 APO on Paramount-ME inside LNSO Dome

1. Paramount ME Robotic Mounting

The Paramount ME's control system uses brush-less DC Servo motors. If the mount is used for survey astronomy all night, every clear night, no other type of motor is sufficient. Note that the life of the brush-less DC servo motor is limited to the service life of the bearings. This translates to about 100,000 hours under normal operating conditions. On the other hand, the life of brushed DC Servo motors is limited to the life of the carbon brushes, which is anywhere from 4,000-10,000 hours according to the manufacturer’s specifications. Brush-less motor also do not "cog" at any rate. This ensures a smooth, constant output when tracking at the Sidereal rate.

 

Paramount ME Robotic Mount (S. Bisque)

The MKS 4000 Control System for the ParamountME

  • Brush-less DC-servo motors ensure long life and smooth operation.
  • Field upgradeable flash RAM permits easy, immediate software updates.
  • Fast slew speeds and consistent torque at all slew rates. A maximum rate of five degrees per second in right ascension and seven degrees per second in declination gets you to the object, fast.
  • Virtually unlimited selection of tracking and slew rates.
  • AutoHome™ capability (to better than one arcsecond) with built-in sensor circuitry on each axis ensure that the mount always knows its orientation (after a one-time initialization), even after power failure.
  • Software controlled "hard limits" prevent the mount from tracking or slewing into itself.
  • User-defined parameters can be stored to on-board flash RAM.
  • Numerous safety features critical to remote operation including current-limit protection, encoder-error limits, acceleration ramping, and user-definable maximum slew speeds.
  • Joystick, TheSky for Windows or TheSky Pocket Edition control.
  • Programmable and updateable Periodic Error Correction.
  • Intelligent German Equatorial flipping eliminates unnecessary long slews.
  • The MKS-3000 control system can track at true lunar, solar, minor planet or comet, NEO or LEO satellite rates, or at almost any user-defined rate (when used with TheSky).
  • TheSky has been updated to provide many new capabilities that were previously not possible. Some examples of these new features include: display a graph of the periodic error of the worm gear; track a low-earth satellite by clicking on the object on the Sky Display.
  • USB and/or serial port communication interface (special USB driver maps as the next logical serial port). This means that no USB-to-serial adaptor is required for USB-exclusive computers.
  • Temperature compensated oscillator with better than 10 parts per million to ensure accurate tracking over a wide temperature range.
  • Built-in thermistor for automatic slew speed adjustment through TheSky6 based on ambient temperature.
  • Soft "reboot" capability. This means that the control system can be restarted through software and does not have to be manually turned off, then on.
  • Faster, more capable internal processor provides room for future enhancements and mount capabilities.
  • More reliable electronic components
  • The internal flash RAM is upgradeable without the need to set DIP switches. This makes future firmware upgrades simpler.
  • New DB9 expansion connector with 2 generic purpose input/output ports for open-ended applications. These pins can either be inputs or outputs and used for user-specific purposes.
  • Software Bisque is soliciting feedback from our Paramount ME customers for the ultimate "best use" of these features. Some possible applications include
  • A 'panic button' input to stop the mount.
  • A slew-complete signal.
  • A timed pulse for camera shutter control.
  • Four general-purpose, high powered driver outputs, which can either be used to drive a DC or stepper focus motor or other astronomical device.

Performance Specifications

  • Periodic Error (Tracking) - The right ascension gear has 5 arcseconds periodic error or less, before periodic error correction and without ProTrack.
  • Backlash - The spring-loaded worm-to-gear interface has virtually zero backlash in both the right ascension and declination axis.
  • Pointing - Less than one arcminute RMS all-sky pointing. (Typical results vary from 10 to less than 60 arcseconds all-sky pointing. Results may vary depending upon the optical system, pier and other variables.)
  • Homing - When permanently mounted, the Paramount ME can be restarted (powered off then on) with the identical pointing and tracking each night.

Paramount-ME Physical Specifications

Specification

Details

Design

German Equatorial Mount (GEM) with all stainless-steel and anodized aluminum construction. ( Worms and the Versa-Plate plungers are manufactured from brass.)

Weight

Overall weight (base plus Versa-Plate) is 29.5 kg (65 lbs.) without optical tube assembly or counterweights.

Maximum Dimensions

The overall "maximum" dimensions of the Paramount ME will vary depending upon the following factors.

  • The dimensions of your optical tube assembly (OTA).
  • How the OTA is mounted to the Versa-Plate (using a dovetail, OTA rings, or other mechanism).
  • The length of the counterweight shaft (which depends upon the weight of the payload).
  • The height of your pier.
  • Your longitude.

Approximate "Standalone" Paramount ME Dimensions

This table below gives the maximum dimensions of the Paramount ME without additional equipment.

Description

Dimension(s)

Minimum dimensions

  • no Versa-Plate
  • no counterweight shaft
  • Declination shaft oriented vertically
  • 15 degrees altitude

48 cm x 30 cm x 58 cm (19 in. x 12 in. x 23 in.)

Maximum height of the Paramount ME and  Versa-Plate when:

  • Versa-Plate is mounted at the forward-most position)
  • Paramount ME 's altitude is set at 58 degrees.

86 cm (34 in.)

Maximum width of Paramount ME and a standard length (18 in., 46 cm) counterweight shaft (no OTA).

This dimension is measured from the center of the Paramount ME right ascension housing to the end of the counterweight shaft when the OTA is pointing at meridian (that is, the counterweight shaft is horizontal).

71 cm (28 in.)

Important Note

The overall maximum width of the Paramount ME and optical tube assembly depends upon:

  • Maximum dimensions of the primary OTA
  • How the primary OTA is mounted (OTA rings, dovetail, other means)
  • Dimensions of additional equipment that is mounted to primary OTA (finder 'scopes, smaller OTAs, other).

Instrument capacity (carrying capacity)

68 kg (150 lb.) instrument capacity. This amount does not include the weight of the counterweights. Therefore, the total carrying capacity (instruments plus counterweights) is 136 kg (300 lb.).

Gear specifications

All aluminum 11.45-inch (29 cm), 576 tooth research-grade right ascension gears and 7.45-inch (18.9 cm), 375 tooth declination gear each with guaranteed 5 arcsecond or less peak-to-peak periodic error before periodic error correction.

Gear construction

Precision CNC brass worm gears; precision CNC integrated all aluminum right ascension and declination gears.

Bearings

8.8-inch O.D., 5.9-inch I.D. right ascension bearings, 6.7-inch O.D., 4.3-inch I.D. declination bearings.

Worm blocks

Spring-loaded right ascension and declination worm block assemblies can be engaged for near zero backlash, or disengaged for adjusting payload balance.

Local operation

Joystick manual control (10-foot cable included) or PC- or Mobile Device-interface control (using TheSky or TheSky Pocket Edition).

 

Paramount ME Joystick (S. Bisque)

 

Cabling

Through-the mount wiring for mount control plus auto-guider input, parallel or serial port CCD camera control and two additional devices (dew heater, video camera, etc.). A large access hole permits the addition of custom cables through the mount.

 

Counterweights

Two 9 kg (20 lbs.) counterweights are provided. Additional counterweights can be purchased from Software Bisque. See the Counterweight accessories for details.

Latitude adjustment limits

Latitude wedge can be adjusted from 15º to 58º. Software Bisque sells an optional Latitude Adjustment Wedge that allows the Paramount ME to achieve polar alignment at any latitude (0-90 degrees).

Azimuth adjustment limits

The azimuth can be adjusted plus or minus 4 degrees.

Azimuth adjustment design

The Paramount ME has a precision 11-inch azimuth adjustment "bearing" for easy polar alignment.

This robotic mount assists all telescopes to point and track the sun.

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