Trident GT - Direct Friction Drive

Direct Friction Drive
Up to 90 kg / 200 lb Payload*

Optimized for safe remote observatory use

Make efficient use of your remote pier

Full Specifications

• 90 kg photographic payload*
• 40 kg mount head weight
• Direct friction drive
• 4-level remote safety system
• Slow and repeatable 16-minute periodic error, easily handled by an optical PEC system
• Ceramic-metal hybrid drive
• USB/WiFi/Ethernet connectivity
• Officially supported Open Source OnStepX control system
• JTW Manticore controller
• Magnetic failsafe brake 
• Preloaded precision roller bearings
• Maintenance-free design
• 0.12" Resolution
• 10° per second maximum slewing speed by default. Unlockable to 20° per second
• On-the-fly changes to microstepping for fast slewing or fine tracking
• StealthChop™ silent running, no more stepper motor chirping
• 0° to 90° latitude range
• ±5.0° azimuth adjustment for polar alignment
• Aerospace aluminium and stainless steel construction
• Sustainable metallic, textured powder-coated finish
• ASCOM and INDI drivers
• Mobile app turns any mobile device into a smart hand pad
• Optional deluxe wireless hand pad 

*Maximum payload depends on more than just the total mass of the telescope, please contact us for advice if you are unsure. 

Remote Safety System

The Trident GT incorporates four independent layers of safety protection -

• Level 1 - Non-volatile FRAM memory will remember the mount's position between power cycles and software limits will prevent unintended motion. The OnStepX control also prevents motion in the event of erroneous settings, e.g. time/date/site errors that could otherwise cause an unsafe GOTO.
• Level 2 - Optical home position, this is a hardware position and takes precedence over software positions ensuring safe recovery of position even in the event of software precautions failing. 
• Level 3 - Optical overtravel prevention. This overrides any software definitions and prevents an axis from going beyond the defined limits.
• Level 4 – Hardware overtravel prevention. Physical stops make it impossible for the mount to travel beyond the defined limits.

Please note that these precautions do a great deal to prevent but do not guarantee immunity from events such as instrumentation striking the pier. The Direct Friction Drive also provides an inherent mechanical slip mechanism. In the event of a collision, the drive will slip rather than transmitting the full motor torque through a rigid gear train, substantially reducing the potential for mechanical damage.

Payload mounting system options

• • Single Losmandy/Vixen saddle, adjustable offset, brass clamps to avoid marring your dovetail. 
  • Dual or triple saddles on a JTW mounting arm (as seen in image above)

Saddle upgrade options

There are two options for a smart saddle on a Trident GT mount. 

• AFC
  • 23 Amps max continuous power output
  •  XT60 Power in
  • USB 2.0 Hub (Mount + 3 ports)
  • 2x 8A 2.1/5.5 Jacks
  • 2x 4A 2.1/5.5 Jacks - Remotely switchable
  • 5 to 24 VDC 3000mA 2.1/5.5 NUC Power (adjustable)
  • 3x Dew output, 2x Dew sensor channels
  • 2x Accessory ports (OnStepX aux channels)
  • I2C Header (used for atmospheric sensor array)
  • WiFi
• OnStepX Auxiliary Feature Controller (AFC)
• AFC + NUC
  • 11th gen Celeron quad core (max 2.9 GHz)
  • UHD Graphics
  • 16 Gb Ram
  • 500 Gb M.2 SSD
  • Windows 11 (or KSTARS/Linux)
  • WiFi/Bluetooth/LAN
  • 2x USB 3.0 & 2x USB 2.0
• OnStepX AFC as above
• Youyeetoo X1 x86 Mini PC + OnStepX AFC above

Motors and drivers

• Trinamic TMC2209 stepper drivers
• StealthChop™ – Very quiet motor operation. Used during tracking.
• SpreadCycle™ – High-performance current regulation. Used during slewing.
• 256× microstepping – Provides 102,400 commanded microsteps per motor revolution for extremely fine motor control.
• StallGuard4™ – Sensorless motor-load monitoring for stall detection without an encoder.
• Advanced protection – Overtemperature, short-circuit, overcurrent and driver fault protection.
• High-torque motors - 60% more torque than our previous motors, providing greater operating headroom under heavy loads and during rapid slews.

Deluxe SHC2+ Hand Controller option

The OnStep SHC2+ is a modified version of the Smart Hand Controller. This is a fully functional controller and can do any task that a computer can do, even installation and utility functions. This is an old school hand pad with modern functionality.

• OLED screen, dimmable, works in low temperatures
• Glove friendly, tactile (read: clicky buttons)
• Full database of objects
• Setup and utility functions
• Dimmable red LED worklight
• WiFi operation
• Hangs from your neck and can be unclipped for incredible ease of use. 
• Li-ion battery and built-in BMS

Mount Installation options

Assuming you don't already have a tripod or pier, we can supply everything you need to install your mount. 

• Standardized 3 ft / 1 meter height, 8"/ 200 mm diameter JTW vertical pier including anchors.
• Custom height JTW pier, specs as above but for a height of your choosing. Please contact us for 3D modelling your observatory to calculate the correct height if need be. 
• Custom equatorial pier, also known as a dog leg, bent or knee pier. These need to be custom built to your latitude but eliminate the need for meridian flips. 
• Berlebach planet tripod. Modified with the standard JTW fitting. The best option for a Trident in mobile use. 

Pier adapter options

Please note that the JTW pier adapter is part of the azimuth alignment. If you wish to mount to another system you will need a plate between the JTW plate and the pier, if you do not wish or cannot otherwise drill the pier to match. We can make custom CNC machined plates on request. 

Laser engraving options

Laser engraving has both practical and cosmetic applications. 

• Security
• Internal and external markings of the mount's order number and some number/lettering relevant to the owner. To allow easy identification in a remote setting alongside easy identification in the event of theft/loss. 
• Cosmetic
• Names and logos of clubs, etc. Anything of personal importance.

*Payload

After 8 years of Tridents in the field, from the P75 to the GT, we're upgrading the payload. We were too conservative with the original payload rating of 75 kg, many people have carried larger loads successfully. However, payload capacity depends on more than the total mass of the system. Please contact us in advance if you intend to carry a very heavy load and we will analyse your individual configuration and provide the recommended setup.

Further Information 

Please see our social media for many more examples of setups and images made with our Trident mount.

JTW Astronomy Facebook

JTW Astronomy Instagram