Astroasis Oasis 7x36mm Filter Wheel

The Oasis 7x36mm Filter Wheel is a completely flat component without an external motor casing. This is especially important when using a rotator with protruding motor. Without large spacers between the rotator and a filter wheel, the motor casings can interfere with each other. However, the required spacers can mean the required back-focus cannot be achieved.

Features include

• Completely flat with 21mm thickness
• Special driving mode and very high accurate repeatable filter position
• Large bearings and stable disc running
• Central screw improves the overall rigidity of the filter wheel
• Completely and easy anti-light-leakage
• One disc is compatible with 36mm/31mm unmounted, and 1.25″ mounted filters
• Compatible with ZWO/QHYCCD/Touptek/Player-one cameras
• Compatible with ZWO/QHYCCD/Touptek OAGs
• No need to remove the filter disc when connecting the camera with screws
• Support running temperature low to -30°C
• USB Type-C power supply and data port
• Support USB HID device interface, driver-free for Operating Systems.
• Support ASCOM interface
• Support INDI
• Built-in temperature sensor

Completely flat

This product has 21mm thickness. The motor is completely built-in and the product is completely flat.

The USB Type-C interface is used for both power supply and data communication, without the need for a separate power supply or other interfaces. The shape was carefully designed.

Special designed driving mode, and filters can be precisely positioned

The more precisely the filter is positioned, the better flat frame can be captured for accurate calibration. We use a combination of mechanical switches and sensors to precisely position the filters. Each filter has its mechanical base position, and the special driving method can keep the filter stable in its mechanical base position.

The mechanical switch provides the base position of the filter, so the positioning accuracy of the filter is only related to the mechanical characteristics of the switch, and has nothing to do with the accuracy of the sensor’s detection precision, nor does it have anything to do with the resolution of the motor. For the same filter, the mechanical switch provides much higher position accuracy than the sensor can provide.

The sensor layout is similar to a 3-8 decoder, which is independent of positional accuracy, but is good for improving the accuracy of identifying different filters.

After a long period of research and experimentation, we finally adopted a special, belt-like driving method. This approach has the following advantages:

1） This is a friction driving mode. There is no gap and other factors that affect the positioning accuracy, which is conducive to improving the positioning accuracy

2） More durable and reliable

3） When the target filter has been positioned, it can generate reverse tension which cooperates with the mechanical switch to firmly fix the filter in the intended position.

This driving method is inspired by vinyl record players.

Large bearings, stable disc running

We use large diameter bearings, which makes the filter disc run very stably. At the same time, the weight of the bearing is also very light, and it does not add much overall weight.

Central screw

Both the front and back shells are CNC machined from a single piece of aluminum alloy. Our design allows the center of the front and back shell to be in direct contact, and an M4 screw can be used to lock the front and back shells in the center. This design effectively improves the overall rigidity of the filter wheel.

Anti-light-leakage (including front and back shells, USB port, screw holes, filter windows)

For filter wheels, anti-light-leakage is a thing that must be considered. We took into account all the areas that could cause ambient light to leak through and designed the product to prevent ambient light from leaking into the filter wheel. These include the fitting of the upper and lower shells, the USB socket, the screw holes near the filter window, and the gap between the shell and the camera or OAG when screws are used to connect the camera or OAG.

1）The upper and lower shells can fit together like bottle caps to prevent light leakage

2）Anti-light-leakage of the USB socket. Our carefully selected Type-C socket itself does not leak light. A blackout mat is inserted between the gap of the socket and the shell to ensure that the gap between the socket and the shell does not leak light.

3） There are some screw holes in the upper and lower shells for connecting to the camera or OAG. When it is not necessary to use screws to connect the camera or to the OAG, the dedicated screws can be screwed from the inside of the filter wheel to prevent light leakage from the screw holes.

4）When using screws to connect the camera or OAG, an elastic light-shielding spacer can be inserted in the recessed area of the filter window to prevent light leakage from the gap between the filter wheel and the camera or OAG.

Compatible with 36mm/31mm unmounted, and 1.25″ mounted filters

This product can be used to install 36mm unmounted filters, 31mm unmounted filters, and 1.25″ mounted filters. With dedicated 36mm or 31mm filter frames, we can convert these two unmounted filters into mounted filters and then thread them into the filter disc. The 1.25″ filter can also be attached to the filter disc via a dedicated adapter.

With this method, we don’t need to use any screws or a screwdriver to install the filter, which eliminates the risk of screws or screwdrivers scratching the filter. At the same time, once the 36mm or 31mm unmounted filter is installed in the filter frame, it is very convenient to uninstall the filter from the filter disc or install it again in the future, and there is no need to consider the front and back of the filter every time.

In addition, one filter disc is compatible with all the three types of filters at the same time. There is no need to change the filter disc, and all the three types of filters can be installed and used at the same time. This improves the utilization of equipment and save money for users.

Compatible with ZWO/QHYCCD/Touptek Camera and OAG

This product is compatible with ZWO/QHYCCD/Touptek cameras and OAGs. There are two methods to connect a camera or OAG. One method is to use M2.5 or M3 screws to connect the camera through the screw holes in the shell. Another option is to connect a camera or OAG with an M42 thread by using the M48-M42 adapter.

No need to remove the filter disc when attaching the camera with screws

Users can connect the filter wheel to the camera without removing the filter disc. There are two holes in the filter disc at the specific locations where screws and screwdrivers can pass through it to connect the filter wheel to the camera. And due to our special filter detection method, such holes do not impact the accuracy of the filter detection.