SPECIAL EXCLUSIVE RUBY OFFER TO FPVMANUALS USERS
For a limited time, you can order the Ruby from uThere with a $50 USD discount if you use the ‘discount code’ FPVMANUALS.COM.  Keep in mind that Ruby is currently back-ordered.  Your order will be a pre-order for the next batch which will be available late July / early August. Click here to order.

The new RUBY by uThere is an exciting addition to the lineup of available autopilots and flight stabilizers.  I’ve been following RUBY’s development for a while and have been working with uThere to document how to implement it within a Ritewing FPV Zephyr. This manual shows the various steps needed to make this work.

References

1. Refer to uThere’s RUBY installation documentation, which has many more details which we’ll skip in this manual.
2. Refer to the Zephyr FPV Build Manual for assembly instructions for the FPV Zephyr.
3. See RUBY in action auto launching the Zephyr in this build manual 5 times in a row

Component Placement

For this FPV Zephyr we are assuming that you have the following equipment layout:

1. Main equipment bay in the center of the wing.  This bay holds the OSD, etc.
2. Two parallel batteries infront of the main bay and close to the LE
3. The RC RX on the right wing, about 18″ away from the main bay
4. The Video TX on the left wing about 18″ away from the main bay

The main RUBY board, GPS shield, and USB dongle will all be located in the main equipment bay.  See the picture below for the location of the main bay. The main bay here is about 7″ x 4″ in size.  The magnetometer unit is located on the bottom of the right wing and at least 10″ away from the battery and servo to prevent magnetic interference.

Layout of Ruby components on Zephyr Wing (click to zoom)

Required Cables for the Zephyr

To connect the RC RX that is located as described above, a custom 24″ long ribbon cable will be required.  uThere will provide you with this cable as long as you request it during the purchase process of your unit.  If your RC RX is all the way at the wingtip of your 54″ or 60″ Zephyr, you will need an even longer cable.

You will also need a 24″ long cable for the Airspeed/Magnetometer unit so that you can place it far away from the batteries and servos.

The rest of the cables that ship with the RUBY are fine, as long as you locate all of the components in the main equipment bay as described here.

Airspeed / Magnetometer

Place the airspeed / magnetometer on the underside of the right wing and as far away from the battery as possible.  Make sure you request a cable for the airspeed/mag that is at least 24″ long during ordering.  For reference, watch the magnetometer video from uThere.

I used the soldering iron technique to make the cavity for the magnetometer and the slot for the Pitot tube.  To cover, I used Shipping tape.  The last step of the Zephyr build will be the lamination process, which will provide another protective layer over the airspeed / magnetometer.

Make sure that the area in-front of the magnetometer is not air tight. The static port (the nozzle on the airspeed pressure sensor located closest to the board, which doesn’t have the pitot tube attached)  needs to sense ambient atmospheric pressure to compare with the “ram” pressure coming into the pitot. So make sure that the airspeed/magnetometer is not sealed airtight. It’s best to have this venting hole on the bottom side of the airfoil with a hole leading to your chamber, since the pressure on the bottom side will be closer to ambient. I ran the wire on the top of the wing and put a hole through to the wing with a soldering iron and copper wire so that I could run the wire.

Note also that, like the main RUBY controller, the airspeed/magnetometer needs to be parallel  or orthogonal to all plane axes.  In our build, we have to make sure that the airspeed / magnetometer is not flush with the curved front of the Zephyr airfoil and in fact is parallel to the plane axes.

Mag/As on the bottom side of the wing, parallel to all plane axis.

Power Meter and Wire Harness

Prepare the power meter

The Zephyr with a typical Hacker A30-10L motor can draw significant amps (50+ amps).  The standard soldering pad connections on the power meter are not strong/thick enough to carry that much current.  Therefore, you’ll need to add solder to the ‘pads’ of the power meter.  You need to do that on both the “+” side and the “-”/ground side of the power meter.

Power Harness

If you run your Zephyr with 2 parallel batteries, you should make a wire harness to connect the batteries to the power meter.  The power meter will sit after the batteries and before the power meter of your OSD.  In this build, I am using an ImmersionRC EzOSD.  My batteries use XT60 connections and the EzOSD power meter uses DEANs connections.  To be able to disconnect the RUBY power meter from the power harness, I chose to use 4mm motor connections between the battery lead and the RUBY power meter — this connection takes less space than a XT60 or Deans coupling would.  Instead of using electrical tape to wrap the power meter, I am using a piece of 3/4″ heat shrink.

Add extra solder to the pads!

Completed power harness

Place the main unit and GPS shield

The main controller unit is placed in the main bay.  The large RUBY logo can face up or down — does not matter.   But, the unit needs to be level and not point up or down.

I placed the GPS unit on the bay cover with double sided servo tape.

Main bay with Ruby and EzOSD

RUBY configuration and hookup to RC RX

During the beta period, uThere will help you with tuning your RUBY configuration for your RC RX.  In my build we are connecting RUBY to an EzUHF RX and 2 elevon servos.

The 8-ch ribbon cable connected to the EzUHF RX.

We’ve posted our first demo of the RUBY in a Zephyr in our new ‘assisted FPV’ series.  First episode is on how RUBY can help you launch your Zephyr, without fail.