RedCat 51 II Automated Flat Panel for ASIAIR Plus

This is a complete automated flat-panel project for the William Optics RedCat 51 II. The panel swings clear for imaging, closes as a dust cap, and provides dimmable neutral-white illumination for flat calibration frames. An ASIAIR Plus adjustable DC output controls the panel through an optically isolated input.

Revision B uses one integrated 120 x 75 mm controller PCB with ESP32-S3, USB-C programming, protected 12 V input, a 6 V servo supply, LED MOSFET output and locking field connectors. Printable parts include the scope clamp, DS3218 servo plate, optical tray, diffuser ring, electronics enclosure and two limit-switch brackets.

https://github.com/pulikantitarun/redcat51ii-automated-flat-panel

Software details and full project is here 

IMPORTANT: PRINT THE FIT GAUGE FIRST

The supplied clamp assumes an 80.0 mm dew-shield outside diameter plus a 0.8 mm EVA or cork liner. Print only 01-diameter-fit-gauge.stl first. It should slide over the shield without force or rocking. If it does not fit, measure the telescope with calipers, change SCOPE_DIAMETER in generate_parts.py, and regenerate the clamp before printing the remaining parts.

PRINTABLE FILES

• Diameter fit gauge

• Scope clamp with servo platform

• DS3218 servo plate

• Flat-panel tray and arm

• Diffuser retaining ring

• Electronics enclosure base and lid

• Limit-switch bracket; print two copies

RECOMMENDED PRINT SETTINGS

• PETG, ASA or ABS; do not leave PLA on a telescope in direct sun

• 0.20 mm layer height

• Four perimeters

• Five top and bottom layers

• 35-45% gyroid infill

• 60% infill for the clamp and tray arm

• Print two copies of part 08

ADDITIONAL HARDWARE

DS3218 20 kg 180-degree 6 V servo with metal 25T horn, two KW12-3 roller-lever microswitches, 82 mm clear acrylic light guide, 82 mm opal diffuser, diffusion film, 12 V neutral-white LED strip, 0.8 mm EVA/cork liner, M3 inserts and screws, one M4 x 35 mm clamp bolt, cable pigtails and a 12 V 4 A supply.

INSTALLATION AND SAFETY

Mount the clamp immediately behind the front dew-shield lip with the servo platform near the 9 o'clock position. The tray must swing sideways and away from the optics. Keep at least 3 mm between the closed diffuser and the dew-shield rim. Test motion without the optical tray installed, use a current-limited bench supply for first power-up, and verify clearance through the mount's full range before unattended imaging.

This is an engineering prototype that has passed KiCad error-level DRC and mesh checks, but it has not yet been physically qualified as a commercial product. Verify the actual telescope diameter, wiring polarity, servo direction, limit switches and power rails before use.

William Optics, RedCat and ZWO/ASIAIR are trademarks of their respective owners. This is an unofficial community project and is not endorsed by those companies.