QHY CFW3L The QHY CFW3L is a seven-position motorised filter wheel for 2-inch mounted or 50 mm unmounted filters. A direct-drive motor takes the shortest route between positions, reducing unnecessary carousel movement.
Manufacturer model: QHY CFW3L · Specifications checked against manufacturer data on 2026-11-03
The QHY CFW3L is a seven-position motorised filter wheel for 2-inch mounted or 50 mm unmounted filters. A direct-drive motor takes the shortest route between positions, reducing unnecessary carousel movement.
The published body backfocus contribution is 21.5 mm, with the manufacturer table listing no additional standard adapter contribution. The usable filter-height limit is 10 mm; clearance must still be left for rotation. Weight is Approximately 900 g.
Use either the QHY camera-control connection or USB-control mode. The QHY 4-pin cable carries both power and commands. In USB mode the wheel can require 780 mA, beyond the 500 mA limit of some USB 2.0 ports; QHY documents auxiliary 12 V power through a 12 V-to-RJ11 cable for that case.
Do not connect USB while operating through the camera-control cable. Select the corresponding ASCOM driver and interface mode. Use plastic gaskets or the manufacturer’s filter masks to retain unmounted glass without pressing metal directly against the filter. The reset button returns the carousel to position 1.
QHYCCD manufacturer documentation
Use the named-model manufacturer connection diagram and the backfocus reference for the selected adapter. Readout mode and output format affect frame rate, noise and full-well capacity.
| Body backfocus (mm) | 21.5 |
|---|---|
| Legacy adapter backfocus (mm) | 0 |
| Usable filter height limit (mm) | 10 |
| Control options | USB control or QHY 4-pin camera control |
| Camera control power | 12 V carried by QHY 4-pin cable; no separate supply in this mode |
| USB current requirement ma | 780 |
| Auxiliary power | 12 V-to-RJ11 cable can supply power in USB-control mode where USB current is insufficient |
| Connection restriction | Do not connect USB while using the camera-control cable |
| Status indicator | Colour-coded filter-position LED; USB/4-pin mode indication |
| Reset | Returns carousel to initial position, slot 1 |
| Recommended cameras | QHY600M PH/Pro |
| Filter retention | Use plastic gaskets between screws and unmounted filter glass; manufacturer supplies filter masks for M/L/XL from September 2023 |
| Driver | Select matching ASCOM USB or camera-serial control driver |
| Backfocus reference | Adapter contribution is a spacing increment, not necessarily physical adapter thickness; newer direct camera connections can omit the legacy adapter |