ZWO EFW - 8 x 1.25" or 31mm

Our latest EFW (Electronic Filter Wheel), larger than the previous but still low on weight. Only 400 grams (14 oz)!

The body is CNC milled from an aircraft graded aluminum block.
We decided to make it thinner, where it measures only 20 mm on the wheel body.

The heart of our EFW comes from NPM, Japan, whose the manufactor for the stepmotor and the quality is trustful and reliable. Guaranteed long life.

We have two specifications:

TYPE1: 8 positions, 1.25″ or 31mm filter can be used.

TYPE2: 7 positions, 36mm filter can be used.

The Electronic Filter wheel can be rotated in both counter clockwise or clockwise direction for filter selection.

There are no need for multiple cables to power this wheel up, just one USB cable does the trick.The power consumption of this EFW is approximately 120mAh @ 5V, which can be operated from the Cooled CCD’s USB hub.

The distance between the filter and sensor is around 10mm when you connect it to ASI1600.

So 1.25″ filters won’t have vignetting up to F5 focal ratio scope and 31mm filter won’t have vignetting up to F2 lens.

Our new RGBL filters are recommended to work with ASI1600, it will offer nearly 1:1:1 RGB color balance.

What’s in the box?

1. 8*31mm or 7*36mm EFW body
2. 1.25″ cover
3. T2 nosepiece
4. 1.25″ holder(with cover and 2 screws)
5. T2-T2 adapter(male)
6. A bag of filter masks
7. USB2.0 2m cable
8. Phillips screwdriver
9. A bag of M2 screws

How to install the filter?

1.25″ filters required to be: threaded shorter than 3mm in length, without threads less than 7mm in height

1. Take the back cover off
2. Lay the wheel down flat
3. Screw-in the filters up
4. Put the back cover on

Take the EFWmini for an example:

31mm and 36mm filter requires: a set of M2 screws and washers needed to fix the filters are included in the package .

1. Take the back cover off. Lay the wheel down flat
2. Hold the filter by the very edges and lay them in to the recess for each position
3. Attach the washers,put in the screws
4. Put the back cover on

Take the EFWmini for an example:

How to connect with the camera and telescope?

How to use it?

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

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

There are 2 ASCOM is for controling 2 EFW in one software.

Mechanical drawing