Advanced Telescope Supplies


Losmandy Precision Equatorial Mounts.

The Losmandy G-11 (with Gemini GoTo approx $A4800 plus GST) price subject to change with $A to $US


The Losmandy G-11 is an ideal astrophotographic mount for the following larger optical tube assemblies: see (specification summary)

  • Meade SCT's 10", 12"

  • Celestron 11", 14" SCT

  • RCOS 10"

  • Astrophysics 10" Mak, 5" EDF, 6" EDF

  • Most other telescope tube assemblies up to 20kg

The Losmandy range is designed for exacting astro-photographic, CCD imaging and visual users in both the field or at a permanent installation.

The G-11 design has evolved over nearly a decade and incorporates features simply not found in competing equatorial mounts. All structural parts are fully machined from aircraft grade aluminum or stainless steel.  Aluminum parts are anodized: a process, which significantly hardens the metal surface and protects it against corrosion. Utilizing the latest Computer Numeric Control (CNC) technology tolerances to within a few thousands of an inch are rigidly maintained across the entire assembly: guaranteeing smooth, precise and dependable performance for many years to come.

Being all-machined, the G-11 is extremely rigid. Add large thrust surfaces plus innovative design features such as; polar altitude lock, oversized shafts, large diameter gears, precision bearings and you create a mount easily capable of supporting payloads of up to 20kg, yet still retain excellent field portability.

Note: while the G-11 can support much heavier telescopes (up to 30kg) the rigidity of the system will depend upon the length of the telescope tube. 

The drive assembly uses dependable, high-torque stepper motors, each driving a super hard, tempered stainless steel worm gear. Unlike the turned gears used in less capable mounts, each worm gear is precision ground to tolerances of a few ten thousands of an inch. The result is consistent tracking accuracy of less than 10 arc seconds without the aid of periodic error correction electronics (also built into every G-11 mount).

Unique to every Losmandy mount is their precision dovetail and saddle system. A single doveplate can be attached to almost any telescope, which can then be attached to the mount saddle in seconds. Perfect balance of the system can then be easily achieved by simply sliding the telescope along the saddle.

Completing the mechanical system is Losmandy’s field tripod: a semi-pier head, coupled to thick walled, large diameter tubular legs giving the field system excellent rigidity and dampening characheristics.  Vibrations literally damp out within fractions of a second, a far cry from the jelly like wobble seem in many competing systems.

Electronically, the G-11 has features tailored for the advanced astro-imager. Three guiding rates, plus three slewing rates. Quartz locked tracking at Sidereal, Solar, Lunar and King rates is also provided. The periodic error correction circuit is unique as it does not alter the set tracking rate, nor slowly drift out of phase. Tracking with the PEC engaged is virtually error free. Any residual mechanical backlash in the declination drive  can also be easily removed by the built in TVC feature, giving the user precise and instant drive correction response. An autoguider jack allows trouble free interfacing with currently available autoguiders.  A compact hand paddle allows drive corrections to be applied in the correct sense, no matter what the optical configuration or telescope orientation  through reversible R.A and Declination switches.

The Losmandy G-11 can also be delivered with (or later upgraded) the Gemini Computerised GOTO system. The  G-11 offers high precision, high payload, excellent stability, innovative compact design and jewel like finish which combine to make it the ideal foundation for a superb astro-imaging system.


G-11 Specification Summary
 
DEC AXIS:
  • All machined stainless steel and aluminum 
  • One 3.75" needle thrust bearing 
  • Two 1.625" needle thrust bearings 
  • One 2.0" needle thrust bearing 
  • Slip clutch - Variable friction-one knob adjustment 
  • 100 oz / in stepper drive - .50 arc second steps 
  •  5.625 diameter 7075 aluminum gear 360 tooth 
  • 1.25" diameter stainless steel shaft precision ground 
  • Removable stainless steel counterweight shaft 
  • 5.0" Iaser engraved setting setting 1deg increments 
  • Dovetail saddle plate - allowing for interchanging of any tube assembly - eliminates the need for DEC tube weights 
  • Instrument Weight to 27kg 
     

     

POLAR AXIS:
  • All machined stainless steel and aluminum 
  • One 3.75" needle thrust bearing 
  • Two 1.625" needle thrust bearings 
  • One 2.0" needle thrust bearing 
  • Slip clutch - Variable friction - one knob adjustment 
  • 100 oz / in stepper drive - .50 arc second steps
  • 5.625 diameter 7075 aluminum gear 360 tooth 
  • Dual supported ball bearing
  • housed stainless steel worn-heat treated and ground 
  • 1.25" diameter stainless steel shaft precision ground 
  • Through the axis polar axis finder-northern and southern hemisphere operation 
  • Unique tangent arm design altitude adjustment 12 - 64 degrees Latitude scale in 2 degree increments 
  • Single knob control azimuth adjustment - bi-directional +/- 8.5 degrees 
  • 5.0" Iaser ground driven setting circle 4 minute increments 
DUAL-AXIS ELECTRONICS:
  • Diamond push button pattern 
  • R.A. and DEC reversing switches 
  • Three photo guide rates; 30%, 50%, and 2x sidereal  rate 
  • Three setting rates; 4x, 8x, 16x sidereal rate 
  • Quartz tracking rates; sidereal, solar, lunar, King 
  • Periodic Error Correction (PEC) 
  • Control Panel Dimmer 
  • Accepts Auto-Guider Systems 
  • Northern and Southern Hemisphere operation 
  • TVC-Programmable DEC Backlash Compensation 
  • 12 Volt DC - 500 MA power use 
  • Tiltable control panel for easy access 
  • Small hand control box for comfortable use 
TRIPOD:
  •   All machined aluminum 
  •   Semi-pier Tripod Design 
  •   Removable legs with clamps 
  •   Adjustable height 34" - 48" 
  •   Tripod weight approximately 20 pounds 
  •   Weight of equitorial head 14kg
  •   Rated Payload 136 kg
     

     
     
     

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