ZWO EFW 7-position Filter Wheel for 36mm Unmounted Filters - Mark II

The new 36mm EFW (Electronic Filter Wheel) independently developed by ZWO for astronomical mono cameras. With the larger body and the newly-added screw holes on the covers, it will give a much easier and more fixable way to connect to ASI cameras.

There are 7 slots inside the EFW and we recommend you use the ZWO 36mm LRGB and SHO filter set with it.

The body is CNC machined from an aircraft grade aluminum block. It is a high quality product with a thickness (optical length) of only 20mm. The heart of the EFW is a quality stepper motor produced by a reliable Japanese company, NPM. When photographing, you can rotate the EFW in both counter clockwise or clockwise direction for filter selection. The whole operation process is rather convenient and efficient.

Comparing to the original 36mm EFW, you will see that the new EFW has a bigger size. The additional screw holes at the front and back covers will allow us directly connecting the 36mm EFW to a wider range of ZWO cameras, whilst bringing the filters closer to the camera sensor, plus making it possible to match it with a ZWO M68 OAG.

There is no need for multiple cables to power this filter wheel up, just one USB cable will do the trick. The power consumption of this EFW is approximately 120mAh @5V, which can be operated from the USB hub of a Cooled ZWO CMOS camera.

All ZWO 36mm filters are supported by this EFW, but if you use filters from a third party, please make sure that the thickness of the filter should exceed 1.8mm.

What’s in the box?

Mechanical drawing:

The best solution of 55mm back focus length:

The latest connection methods for the new 36mm EFW and ASI cameras can be find here: The best solution of 55mm back focus length.

If you are using ASI2600, then directly head over to this instruction: [ASI2600 Guide] 4 Connection methods to get 55mm back focus length.

How to use it?

you just need to plugin the EFW with a USB2.0 cable and install the  ASCOM driver from here.

There are  ZWO Filter Wheel(1) and ZWO Filter Wheel(2) to select,  you can use either one of them.

You can control 2 filter wheels simultaneously from one software.

SPECIFICATIONS

• Limiting F-ratio for ASI1600: f/1.5 with 36mm filters (calculated with ZWO's 2mm thick filters)
• Thickness: 20mm
• Power consumption: appr 120 mA at 5 Volts
• ASCOM compatible
• Positions: 7 x 36mm glass, unmounted or semi-mounted (like Astronomik)
• Weight: appr. 500g (TBC)