The GM3000HPS mount is built for observatories with an instrumentation up to a weight of 100 kg 220 lbs (excluding counterweights). It is ideal for remotized observation sites, and its loading capacity allows for mounting instruments like 200 mm diameter refractors,300 mm diameter Newton reflectors, 450 mm diameter Cassegrains and so on.
Movements are driven by two AC servo motors, with timing belt reduction having zerobacklash.
Both axes feature a classic worm wormwheel pairing. The wormwheels are made of bronze (B14), with a diameter of 244 mm and 315 teeth in right ascension, and a diameter of 192 mm and 250 teeth in declination. The worms are made of alloy tempered steel with a diameter of 32 mm and 24 mm respectively. The axes themselves are made of alloy steel, with a diameter of 80 mm (right ascension) and 60 mm (declination), for the maximum rigidity.
The electronics is housed in an independent control box, easily removable. The
connections of the mount and keypad secutiry lock screws. Only one cable runs from the
control box to the mount. The axes feature an hole allowing for the passage of instrumentation cables. This effectively solves the problem of entangling cables and damaging instruments, especially for remote observatories.
The mount is powered with low voltage, requiring
a maximum power of about 100W. This makes
possible using the mount even in locations with
limited power available.
The GM3000HPS can be controlled completely
using the included keypad, without requiring any
external PC. The keypad is built in order to maintain the maximum readability in all lighting conditions. Both the display and the ergonomic keys, allowing for the use of gloves, feature a red backlight. An heater keeps the display warm for usage below freezing temperatures.
The mount can be controlled using the most common software packages by connecting it
to a PC with the RS-232 serial port or the Ethernet connection, via the 10micron ASCOM
driver or the Meade compatible command protocol. Furthermore, a dedicated software (also included with the mount) can be used to create a "virtual keypad" replicating exactly the functions of the physical keypad. The RS-232 port can also be used to control an external dome. This flexibility makes the GM3000HPS an ideal mount for observatories and remotized observing sites.
The object database contains many star catalogs and deep-sky objects up to the 16th magnitude. Solar system objects can be tracked so that their motion is compensated with respect to the stars. You may load orbital elements of comets, asteroids and artificial satellites into the mount, so that these objects can be tracked directly.
Pointing is made accurate through the usage
of a model containing up to 100 stars, which
allows for the correction of the classical polar
alignment and conic errors, and also of the
most important flexure terms of the optical
tube. In this way it is possible to obtain
pointing accuracies of the order of 15
arcseconds RMS. The same model can be used
in order to obtain the maximum tracking
accuracy, compensating also for the
atmospheric refraction (depending on the
local atmospheric pressure and temperature).
A series of auxiliary functions is provided to
help the user for quick aligning the mount to
the celestial pole. You may also save and
recover the alignment data of different
observing sessions. This function is very useful
if you have many instruments in different
setups, each one requiring different flexure
Tracking through the meridian, a typical
problem with german mounts, is solved
allowing for tracking for up to 30° past the
meridian (configurable), in both directions. In
this way any object can be tracked for at least
The tracking accuracy makes autoguiding not necessary for many uses. The absolute
encoders on both axes allows to obtain a typical tracking error below 1 arcsecond. It is
possible to autoguide anyway, using the ST4-compatible port or through the
serial/Ethernet connection, with a guide rate configurable from 0.1x to 1x. The guide rate
can be automatically corrected for the declination of the target, so that there is no need ofrecalibrating the autoguide when observing at different declinations.
The mount has also dedicated function for easy use in the observatory. A dedicated
connector on the control box panel is used for remotized switching on and off. The instrument can be electronically balanced, without disengaging the worm from the wormwheel. The mount can be parked in different user-defined positions.
The serial RS-232 port can be used to control directly an external dome, avoiding the need
of using a dedicated external PC. Once onfigured with your instrument parameters, the firmware is able to make all the calculations required for positioning the dome slit in front of your optical tube, for almost all instrument configurations.
TECHNICAL DATA SHEET
Type German Equatorial Mount
Weight (mount) 65 kg 143 lbs without accessories
Instrument payload capacity 100 kg 220 lbs
Latitude range 20° 70°
Azimuth fine adjustment range +/− 10°
Counterweight shaft 50 mm diameter, stainless steel, weight 8 kg 18 lbs
Axes r.a. 80 mm diameter, alloy steel
dec. 50 mm diameter, alloy steel
Bearings Pre-loaded tapered roller bearings
Worm wheels r.a. 315 teeth, 244 mm diameter, B14 bronze
dec. 250 teeth, 192 mm diameter, B14 bronze
Worm gears Diameter 32 mm (r.a.) and 24 mm (dec.), tempered alloy
steel, grinded and lapped
Transmission system Backlash-free system with timing belt and automatic
Motors 2 axes AC servo brushless
Power supply 24 V DC
~ 1 A at sidereal speed
~ 3 A at maximum speed
~ 5 A peak
Go-to speed Adjustable from 2°/s to 12°/s (9°/s in r.a.)
Pointing accuracy < 20 with internal multiple-stars software mapping
Average tracking accuracy
< +/− 1" typical for 15 minutes (< 0.7" RMS)
with internal multiple-stars software mapping and
compensation of flexure and polar alignment errors
+/− 30° past meridian in r.a. (software)
+/− 35° past meridian in r.a. (mechanical)
+/− 170° interval in dec. (software)
+/− 172,5° interval in dec. (mechanical)
Communication ports RS232 port; GPS port; autoguide ST-4 protocol port;
Stars: by name, Bayer designation, Flamsteed designation,
Bright Star Catalogue, SAO, HIP, HD, PPM, ADS, GCVS.
Deep-sky: M, NGC, IC, PGC ,UGC limited up to mV = 16.
Solar system: Sun, Moon, planets, asteroids, comets,
artificial satellites. Equatorial and altazimuth coordinates.
User defined objects, fast slewing positions.
User defined mount parking position, 2-stars and 3-stars
alignment function, up to 100 alignment stars for
modeling, correction of polar alignment and orthogonality
errors, estimate of average pointing error, storage of
multiple pointing models, sidereal, solar and lunar tracking
speed adjustable on both axes, declination-based
autoguide speed correction, adjustable horizon height
limit, pointing and tracking past meridian, assisted balance
adjustment, manual or GPS based time and coordinates
setting, dome control via RS-232, configurable
atmospheric refraction, network settings, comets and
asteroids filter, multi-language interface. Remote Assist via
Remote control via RS-232 or Ethernet; proprietary
ASCOM driver or Meade compatible protocol; update of
firmware and orbital elements of comets, asteroids and
artificial satellites via RS-232 or Ethernet; virtual control
panel via RS-232 or Ethernet. Optional Wi-Fi.
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