Description

ZWO EFW 8 x 1.25″/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 manufacturer of the stepmotor, and the quality is trustworthy and reliable. Guaranteed long life.

The Electronic Filter wheel can be rotated in both counterclockwise 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 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 into 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 controlling 2 EFWs in one software.

Mechanical Diagram

Q & A

1. My EFW tries to move but gets stuck and cannot arrive at the right position.

1) Filter is too thick: Filters (not including the threads) must be less than 7mm in thickness and threads must be less than 3mm in thickness.

2) The M2 screw used to secure the filter is too long and causes the wheel to jam.

3) The M42 thread of the scope or the camera is too long and protrudes into the filter wheel, hitting the filter or wheel, and causing it to jam.

2. My EFW spins but never stops, or stops at the wrong position.

ZWO EFW uses an infrared sensor to check wheel position.  If the sensor malfunctions, you can usually resolve it by recalibrating the EFW in the ASCOM driver. Simply click “ReCalibrate” in ASCOM driver interface. It can take up to 60 seconds to perform this action.

3. I use 7-position EFW, normally I had slots 1, 2, 3, 4 filled and slots 5, 6, 7 empty, but then I got the error below and the EFW stopped working. I checked the carousel. It was not too tight or loose.

When using the filter wheel it is very important to keep its internal balance. The weight and distribution of the filters will affect balance. Thus we recommend you space the filters out and evenly distribute them. In this case, install them in slots 1, 3, 5 and 7, then the EFW will work again.

New ZWO EFW 7x36mm

The new 36mm EFW (Electronic Filter Wheel) was 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 milled from an aircraft-graded aluminum block. It is made with high quality and thin with a thickness of only 20mm. The heart of the EFW uses quality stepmotors produced by NPM, Japan, which can be very trustworthy. When photographing, you can rotate the EFW in both counterclockwise or clockwise directions for filter selection. The whole operation process is rather convenient and efficient.

Compared to the original 36mm EFW, you may find the new EFW has a bigger size. The screw holes on the front and back covers shall not only allow us directly connect the 36mm EFW to the camera and bring the filters closer to the camera sensor, also make the it possible to match it with M68 OAG.

There is no need for multiple cables to power this filter 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 CMOS’s USB hub.

All ZWO 36mm filters can be perfectly supported by this EFW. But if you use filters from third party, then please make sure the thickness of the filter should be between 1.5mm and 3.0mm (the thickness of the filter frame is 1.8mm).

What’s in the box?

Specifications for the darkening sets(4pcs):

External diameter: 88mm. Inner diameter: 55mm (2pcs) & 58mm (2pcs). Thickness: ≤0.2. 4pcs in total.
* The reason for including the darkening sets is to help solve the light leaking issue occurring in the gap of the filter wheel and camera.

How to install the darkening sets:

Mechanical diagram

The best solution of 55mm back focus length

The latest connection methods for the new 36mm EFW and ASI cameras can be found 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

ZWO EFWmini (5 x 1.25″or 5 x 31mm)

The smallest and most lightweight 1.25″ Electronic Filter Wheel in the world!

300g ONLY! Small than your hand!

The body is CNC machined from a full block of aircraft-grade aluminum.

Very thin design, 20mm ONLY

The step motor is the heart of the EFWmini, which is made by NPM from Japan. You can trust its quality and reliability.

Supports both 5*1.25″ filters or 5*31mm filters

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

Only one USB Cable is enough to power up the EFW, the max power consumption is around 120ma@5V, so you can connect it from the USB 2.0 hub of our cooled cameras.

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 filters won’t have vigentting 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. EFWmini 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

Mechanical drawing

How to use it?

you just need to plugin the EFW mini 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 for controlling 2 EFWmini in one software.