The JTW P75 is a direct friction drive mount that breaks the traditional rule that a heavy payload needs to break the bank. It's an engineered-for-purpose mount that is meant to be extremely economical, to do one job well and to do it reliably.

The purpose of this mount is to open doors for astronomers and astrophotographers who require an observatory class mount without the significant investment that's usually required. This mount has very high performance and can also be upgraded significantly, it has an open source control system and can be maintained with COTS (commercial-off-the-shelf) components. This is our breakout system, to demonstrate what our products are capable of and to give a preview of what our bespoke systems are capable of.

Engineered for purpose means that you are not paying for performance that you can't use in the real world. Our engineers all have an industrial background, every step of the design process is made with considerations to production, machinery, tooling, material selection and material costs, etc, this is a very efficient way to manufacture a product and results in high performance for a low cost. Our product testers are astronomers who also operate in the real world, user experience is also a large factor in the design of our products.

Additional features -

• Support for industry standard BiSS-C & SSI protocol absolute encoders
• Ability to tune motor currents without reflashing the OnStep firmare
• Ability to tune motor ticks per degree without reflashing the OnStep firmware
• Ability to tune encoder ticks per degree without reflashing the OnStep firmware
• Open loop positioning, absolute encoders used for pointing. Negates the need for home sensors and retains position after power loss

Technical Specifications

Highlights of the P75 Trident include -

• 75 kg photographic payload
• Based on the proven OnStep open source control system
• Ceramic-metal hybrid drive
• 180 s unguided imaging out of the box*
• Direct friction drive, no reduction rollers to add to periodic error
• Preloaded precision roller bearings throughout
• 0.12" Resolution
• 15° per second maximum slewing speed, 7.5° advised
• 23-bit or 24-bit absolute encoders supported (upgrade option)
• Stainless steel drive available for difficult environments (coastal or dusty)
• On-the-fly changes to microstepping for fast slewing or fine tracking
• Missed step detection - advanced electronics use the motors own coils as a pseudo-encoder
• StealthChop™ silent running, no more stepper motor chirping
• <0.2 px guided performance
• 0° to 90° Latitude range
• ±5 Degrees of 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 handpad
• WiFi and USB

 
Upcoming features in the next software update, available free of charge, closed loop positioning. Uses the encoders actively in the tracking and negates the need for guiding.

Upgrades

• 23 bit absolute encoders
  
• 24 bit absolute encoders
• Stainless steel drive wheels
• Additional counterweights (12 kg)

*Depending on setup, some systems are more difficult to carry than others, e.g. refractors with long focal lengths.