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Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride
Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride
Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride
Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride

Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride

by Starlight Instruments
SKU SI-HSM20
CA$518.00 - CA$518.00
CA$518.00
CA$518.00 - CA$518.00
CA$518.00
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  • Adds automated, repeatable focusing to Feather Touch focusers
  • Features a simple manual focus override by turning the motor housing
  • Available in three models: HSM20, HSM30, and HSM35
  • Delivers resolutions up to 24,300 steps per inch
  • Requires a Focuser Boss II or EFS controller (sold separately)
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  • Description
  • FAQ
  • Specifications
  • In the Box
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  • Warranty

  • Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride

    The Starlight Instruments Handy Stepper Motor (HSM) adds precise, automated control to Feather Touch focusers, delivering resolutions of 19,450 steps per inch on the HSM20 and 24,300 steps per inch for the HSM30 and HSM35 models. It works with two Starlight controllers, the Focuser Boss II and the Electronic Focusing System (EFS), and its housing doubles as a manual override: turning it disengages the gears so you can focus by hand. A built-in temperature thermistor supports temperature control through either controller.

    HSM20, HSM30 & HSM35: Fitment Across 3 Focuser Classes

    Starlight produces the HSM in three models, each for a group of focusers. Choose the one that matches your focuser.

    • HSM20 Fits: any Feather Touch Micro Focuser for SCTs, the Feather Touch retrofit pinion assembly upgrades (MPA retrofits for Takahashi and Tele Vue) and Feather Touch Crayford focusers; the site copy says the 2.0" Feather Touch focusers.
    • HSM30 Fits: the 2.0", 2.5" and 3.0" Feather Touch rack and pinion focusers, the TRUE 3.0" Feather Touch, and the 2.7" Astro-Physics focuser with the Feather Touch upgrade.
    • HSM35 Fits: any 3.5" Feather Touch focuser, and the Astro-Physics 3.5" and 4.0" focusers with the Feather Touch pinion assembly upgrade.

    Up to 24,300 Steps Per Inch for Critical Focus

    The HSM30 and HSM35 have 24,300 steps per inch, and the HSM20 19,450 steps per inch. Fine steps let an autofocus routine make small adjustments, which matters most with fast optical systems where the zone of sharp focus is shallow.

    With the built-in thermistor, the EFS and Focuser Boss II can use temperature to adjust focus as the night cools; the EFS brochure lists temperature compensation and backlash correction among its features.

    Manual Override by Turning the Housing

    The core design of the Handy Stepper Motor delivers the precision of automated focusing without sacrificing the immediate, tactile control of manual adjustment. A simple counter-clockwise turn of the motor housing disengages the stepper motor's gears, allowing you to use the focuser's own knobs as you normally would. Turning the housing clockwise re-engages the motor for automated control.

    This is useful for initial setup, quick visual checks or whenever the controller is not connected.

    Control via 2 Systems: Focuser Boss II and EFS

    The HSM is a component that requires a dedicated controller, sold separately. Starlight offers two options: the Focuser Boss II and the Electronic Focusing System (EFS). The EFS comes with an ASCOM driver (ASCOM Platform 6 or later), a hand controller and its own features such as backlash correction and temperature compensation. The Focuser Boss II hub runs one or two focusers over serial, USB or wired Ethernet, with optional WiFi, through an ASCOM Local Server, and Mac users can use TheSky X and Equinox. The motor's built-in thermistor provides temperature control through either controller.

    Starlight HSM vs. PDMS: A 2-Motor System Comparison

    Starlight Instruments offers two motor systems for its focusers, the direct-drive HSM and the belt-driven Posi Drive Motor System (PDMS). Starlight offers the PDMS for heavier image trains and for non Feather Touch focusers, stating it can lift in excess of 56 pounds.

    • Handy Stepper Motor (HSM): A compact, all-in-one unit that clamps directly onto the focuser's pinion assembly. Turning the housing disengages the gears for manual focusing.
    • Posi Drive Motor System (PDMS): This system uses a timing belt and pulleys. Starlight offers it for heavier image trains and non Feather Touch focusers. For manual mode, you loosen a thumbscrew and turn the motor housing to slacken the belt.

    Installation: A 4-Step Process on the Pinion Assembly

    The HSM comes with the two Allen wrenches its installation uses, 1/16 and 7/64. The motor clamps onto the silver housing of the pinion assembly after the focus knobs are removed.

    The steps: remove the gold knob and then the black knob with the 1/16 wrench; start the small pin into the gold knob and slide the clamp onto the silver housing (a snug fit, so use a gentle back and forth motion); tighten the clamping screw with the 7/64 wrench; center the gold knob in the slot and tighten it with the 1/16 wrench. Then turn the black focus knob to check the gold knob does not rub on the motor housing; if it does, loosen the clamp and move the whole assembly slightly in or out.

  • How do I use the manual focus override on the Starlight Instruments HSM?

    Using the manual override is immediate and requires no tools. Simply grip and turn the round motor housing counter-clockwise to disengage the gears. This allows you to turn the focuser's knobs by hand. To re-engage the motor for automated control, turn the housing clockwise.

    Do I need a Focuser Boss II to use the Handy Stepper Motor?

    Yes, the Starlight Instruments Handy Stepper Motor requires a controller. You must use either the Focuser Boss II or the Starlight Instruments EFS (Electronic Focusing System) to power the motor and interface with your computer software. The motor cannot be operated without one of these controllers.

    Which HSM model do I need for my Feather Touch 3.5" focuser?

    For any 3.5" Feather Touch focuser, you must use the HSM35 model. The HSM35 is made for any 3.5" Feather Touch focuser.

    What is the main difference between the Starlight Instruments HSM and the PDMS motor?

    The primary difference is the drive mechanism and override function. The HSM (Handy Stepper Motor) is a compact, direct-drive motor that clamps onto the pinion and features an instant, tool-free manual override. The PDMS (Posi Drive Motor System) is a belt-drive system that Starlight offers for heavier image trains and non Feather Touch focusers; for manual focus you slacken the belt.

    Can I install the Handy Stepper Motor myself?

    Yes. Remove the focus knobs with the supplied 1/16 Allen wrench, clamp the HSM onto the pinion assembly with the 7/64 wrench, and tighten the gold knob. Starlight's installation sheet, with a separate version for the Feather Touch Micro Focuser, shows each step.

    Does the HSM20 fit my Feather Touch Micro Focuser?

    Yes. The HSM20 is made for any Feather Touch Micro Focuser, and separate installation instructions are published for it. The HSM20 moves 19,450 steps per inch.

    Will the HSM30 fit my Astro-Physics 2.7" stock focuser?

    The HSM30 fits an Astro-Physics 2.7" focuser only if it has been upgraded with a Feather Touch pinion assembly. It will not fit the stock Astro-Physics pinion assembly. You must have the Starlight Instruments upgrade installed on the focuser first.

    Does the Handy Stepper Motor have a temperature sensor?

    Yes, the HSM has a built-in temperature thermistor. When connected to a Focuser Boss II or EFS controller, it provides temperature control through the controller.

    Can I use one HSM motor on multiple different focusers?

    Each model is listed for its own group of focusers: for example, a 3.0" Feather Touch rack and pinion focuser takes the HSM30, not the HSM20. You can move a motor between focusers of the same group.

    What software can I use to control the Handy Stepper Motor?

    Through the EFS or Focuser Boss II, the HSM can be controlled by ASCOM client software. The Focuser Boss II also works with TheSky X and Equinox for Mac users, web browsers, and Android and iPhone apps.

  • Controller Compatibility Focuser Boss II, Electronic Focusing System (EFS)
    Focuser Compatibility Feather Touch Focusers
    Available Models HSM20, HSM30, HSM35
    HSM20 Fits Any Feather Touch Micro Focuser, Feather Touch retrofit pinion assembly upgrade, and Feather Touch Crayford focuser
    HSM30 Fits Any 2.5", 3.0", and 2.0" Feather Touch Rack/Pinion focuser, and Astro-Physics 2.7" with Feather Touch pinion assembly upgrade
    HSM35 Fits Any 3.5" Feather Touch focuser, and Astro-Physics 3.5" and 4.0" with Feather Touch pinion assembly upgrade
    Interface / control Focuser Boss II or EFS controller; manual override by turning the motor housing
    Step resolution HSM20: 19,450 steps per inch; HSM30/HSM35: 24,300 steps per inch

    • Starlight Instruments Handy Stepper Motor w/ Manual Focus Over-Ride

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  • Starlight Instruments 1-Year Warranty on Electronics