Why upgrade the stock Takahashi FSQ-106ED focuser to this Feather Touch?
The primary reasons are lifting capacity and focusing precision. The 3.5" focuser has an 18-20 pound lifting capacity and a 10:1 dual-speed fine focus, and this version's M98x1 female drawtube lets Takahashi accessories thread directly into it.
What is the lifting capacity of this FSQ-106ED focuser?
The 3.5" Feather Touch focusers are rated at 18-20 pounds. Add up your camera and accessories to check they are within that figure.
Can I rotate the Starlight Instruments focuser on my FSQ-106ED for framing?
Yes. The focuser features a 360-degree locking collar. You can loosen the collar, rotate your entire imaging train to the desired orientation for framing your target, and then tighten it to lock the position.
How does the 18-20 pound capacity handle a heavy imaging train on the FSQ-106ED?
Within the 18-20 pound figure, the rack and pinion drive moves the load and the brake can lock the drawtube. Keep at least light drawtube tension, which prevents drawtube tilt and image shift.
When imaging the Horsehead Nebula (B33) with my FSQ-106ED, how does the 10:1 fine focus help?
Imaging high-contrast details like the silhouette of the Horsehead Nebula against the faint red glow of IC 434 needs careful focus. The 10:1 fine focus reduction allows you to make extremely small, controlled adjustments to the focus point. This lets you dial in the tightest possible stars, which in turn maximizes the sharpness of the boundary between the dark nebula and the emission background.
How do I image the Andromeda Galaxy (M31) with my FSQ-106ED and prevent tilt?
The key is a rigid, threaded connection. This focuser's M98x1 female thread allows you to connect your camera and any field flatteners or reducers directly to the drawtube. A threaded connection is more secure than a compression ring, and the end cap collimation screws let you remove remaining tilt.
Is this FSQ-106ED focuser compatible with other Takahashi telescopes?
No. This specific kit is custom-designed exclusively for the Takahashi FSQ-106ED. The Takahashi FSQ106ED is its known fit.
Can I use this Feather Touch focuser visually with a 2" diagonal?
The drawtube has M98x1 female threads for Takahashi accessories. Starlight's site asks buyers to select the tube adapter ring and end cap needed; for a 2" diagonal you need a part that ends in a 2" compression ring.
What motor options are available for this FSQ-106ED focuser?
This 3.5" focuser is compatible with Starlight Instruments' motor systems designed for this size. The recommended options are:
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HSM35 (Handy Stepper Motor): listed for any 3.5" Feather Touch focuser; turning its housing disengages the gears for manual focus.
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PDMS (Posi Drive Motor System): a timing-belt drive that Starlight offers for heavier image trains; the PDMS has a 3.5" Feather Touch version.
Both motors are run by a Starlight controller such as the Focuser Boss II, which offers ASCOM control.
How do I adjust the drawtube tension for my camera's weight?
There is a drawtube tension nut on the focuser housing that can be adjusted with a 3/16 hex key. You should set just enough tension to prevent the drawtube from moving on its own while still allowing for smooth motion. Always keep at least light tension on the drawtube to prevent tilt.
Does engaging the brake affect fine focusing on the FSQ-106ED focuser?
Yes, to a limited extent. The brake thumbscrew is designed to lock the drawtube securely. While it is possible to make minor adjustments with the fine focus knob while the brake is engaged, avoid prolonged use in this manner as it can cause premature wear on the internal brake component.
When would I need to use the end cap collimation screws?
You would use the three collimation set screws on the end cap if you detect tilt in your imaging train, which typically appears as elongated stars in the corners of your image. These screws allow you to make minute adjustments to the angle of the end cap, to square the camera to the optical axis.
