Which QHYCFW3 model do I need for a QHY268M camera and 2" mounted filters?
The QHYCFW3M-SR (Standard) holds five 2" filters, with a 10 mm filter height limit and direct mounting to the QHY268M.
Do I need a separate 12V power cable for the QHYCFW3?
It depends on your control method. If you connect the QHYCFW3 to a compatible QHY camera using the 4-pin CFW port cable, you do not need a separate power supply, as the camera provides power. In USB mode the wheel needs 780mA, more than a USB 2.0 port supplies, so power it through the 6-pin RJ11 port with a 12V to RJ11 cable.
What's the difference between the "US" (Thin) and "SR" (Standard) QHYCFW3 models?
The primary differences are thickness (optical length) and filter compatibility.
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US (Thin) models: Have a shorter optical path (e.g., 15.5 mm for the S-US) and a maximum filter thickness of 5.5 mm. They are ideal for setups with tight back focus requirements, like those using camera lenses.
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SR (Standard) models: Are slightly thicker (e.g., 20 mm for the S-SR) but accommodate filters up to 10 mm thick, making them compatible with nearly all brands of mounted filters.
What do the red and green lights mean when I power on the QHYCFW3?
At power-on the indicator lights for one second: red means USB control mode and green means 4-pin control mode. The mode button is inside the case, so the light is how you check it.
Can I use 7mm thick mounted 1.25" filters in the thin QHYCFW3S-US model?
No. The QHYCFW3S-US has a maximum filter thickness limit of 5.5 mm. To use filters that are 7 mm thick, you would need the QHYCFW3S-SR (Standard) model, which supports a filter thickness of up to 10 mm.
How do I control the QHYCFW3 from imaging software?
Install the QHYCCD ASCOM driver for the filter wheel (4-pin or USB control) and select the wheel in your program's ASCOM Filterwheel Chooser. QHYCCD's guide uses MaxIm DL as the example.
What happens if my computer's USB port can't supply enough power to the QHYCFW3?
In USB mode the QHYCFW3 needs 780mA, while a USB 2.0 port supplies less and some computers limit it to 500mA. Power the wheel through its 6-pin RJ11 port with a 12V to RJ11 cable; the USB draw then falls below 100mA while the motor turns.
What is the purpose of the reset button on the QHYCFW3?
The reset button performs a hardware reset of the filter wheel. When pressed, the internal carousel will rotate to its initial position, which defaults to filter position 1.
Can I use the QHYCFW3XL with a QHY600M camera?
The QHYCFW3XL mounts directly to the QHY600M-PH SBFL (with a special adapter) and the QHY461PH. For other QHY600M models, use the QHYCFW3L or the CFW3M-SR.
