High Quality Bixler 1.1 Build (APM2.x)

This article describes a well planned Bixler Build (by Dave Smith).

http://api.ning.com/files/u325ipbpd7oqTtPXcbe06pO*YRgzw3pmmYp1bMm2Wg9DNb8LsLAgkd2DEDlgEKdYRKjFIMWOg1LkAG4u-fMpgy-Jp9ceEGXv/mainbix6.jpg

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This wiki page is a work in progress and will be completed as the information becomes available.

Overview

I have seen some really horrific pictures on the internet of Bixlers with everything taped to the outside. After digging through the internet, I found the answers I needed to build my plane, but the learning curve was pretty steep.

Hopefully I can help somebody out and save them a lot of frustration by logging my whole build.

The equipment list

  1. Bixler 1.1 ARF (HobbyKing)
  2. Motor (HobbyKing)
  3. ESC (HobbyKing)
  4. SBEC (HobbyKing) - (Optional)
  5. ESC Programmer (HobbyKing)
  6. Motor mount (HobbyKing) - (for spinning bigger props)
  7. APM 2.6 with separate GPS/compass
  8. Radio: Spektrum DX8
  9. Receiver: AR6210, no satellite
  10. Prop: APC 7-5. The HK 7-5 prop came with horrible adapter collars and I do not recommend them!
  11. 25cm 4 position cable (store.3drobotics.com)
  12. 25 cm 6 position cable (store.3drobotics.com)
  13. 5 pin housing (www.digikey.com)
  14. Female-female server extension (15cm x 7 qty) (store.3drobotics.com)

Getting Started

  • I am waiting on my new air-frame after an unfortunate incident with an electrical wire on a windy day.
    • Part of the learning curve, which I will not elaborate upon thoroughly to spare you the anquish.
    • Before I knocked the tail off, I had my plane hitting waypoints, loitering, RTL, and auto-landing.
  • For now, I will show you what I did with the electronics.
    • I do not have telemetry yet, so I just used the stock PID settings and added some I gain. (More on that later.)
  • About using an external SBEC: I chose to do this because I am an RC heli guy, and I often use servos that draw ridiculous current.
    • If you power the servos separately from the motor, there is less chance of either one shutting down due to over-current draw.
    • But you also add a second electronic device that can fail.
    • When the motor is at max throttle and servos are fully deflected, such as on a windy day, the separate BEC gives you some headroom.
  • I will post pics of the air-frame assembly when I receive it next week.

Programming the ESC

Set up the programmer card as follows:

http://i1302.photobucket.com/albums/ag127/davesmith111/internet%20pics/205cdb8d-fae5-47fe-99bf-fcf541a96d87_zpsba9c68f8.jpg
  1. Set the low voltage cutoff to its lowest setting to allow the APM failsafe feature do its job.
  2. Don’t worry about FWD vs REV; you can just switch two of the motor wires if the motor spins backwards.
  3. Connect the ESC to the card and the motor (no prop).
  4. Plug the ESC into a battery and you should get one tone from the motor, letting you know that programming is complete.
  5. Disconnect the programming card and then the battery.

Wiring the ESC and BEC

I chose to use EC3 connectors in my build, because all of my batteries have them. XT-60 are just fine.

  1. Cut the servo power lead off of the BEC at the connector.
  2. Solder the BEC power cables along with the ESC power cables into your connector (this can be a little tricky).
    1. Get the solder hot in a connector and insert an ESC wire.
    2. Keep the connection hot and slip the BEC power wire in next to it.
  3. I chose to run my servos at 5V from the BEC.
    1. There is a jumper on the end of it that lets you select 5 or 6 V.
    2. Before you reinstall the electronics secure the jumper on the BEC with a glob of hot glue or shoe goo.
  4. Pull the center (red) pin and wire from the ESC receiver connector.
    1. This disconnects the built in BEC from the ESC. You don’t need it since it is only powering the motor.
    2. Tuck the ESCs BEC wire away with heat shrink tubing over the end.
    3. You will need access to it if you need to re-program the ESC.
  5. Add 100mm 14 gauge motor lead extensions with 3.5mm banana plugs to make it easier to wire the Bixler’s motor later.

Here it is ready to go:

http://i1302.photobucket.com/albums/ag127/davesmith111/internet%20pics/7db2fd9a-9ee0-40a7-92d3-6fe473d97ce1_zps37b398da.jpg

Mount the APM and install the wiring

  1. Make a 45 x 100 mm mounting plate for the APM using 5mm plywood (or plastic or fiberglass board).
  2. Use a 1” square of Kyosho Zeal Gel or Dubro foam under each corner of the flight controller to provide vibration suppression.
  3. Zeal has high strength double sided adhesive, but if your pads do not, consider using “Welders Glue” available at Amazon or Lowes.
    1. Re Welder’s Glue: it is contact cement. Lightly cover each surface you wish to bond and let them dry for about five minutes.
    2. Then carefully align and put the two surfaces together and for immediate bonding.
    3. I will also use Welder’s Glue for assembling the foam air frame and building an access door in the fuselage.

The APM mounted on the plate: (Pictured are the stock cables to the GPS. I will actually be using the 30cm cables)

http://i1302.photobucket.com/albums/ag127/davesmith111/internet%20pics/13968d8e-044e-4000-9768-11eb05257832_zps129a65ba.jpg

Preparing the Fuselage

  1. For this build, the APM is mounted inverted and we want to get it level with the fuselage (level with the line of flight).
  2. You can see that the wing has a positive angle of attack when the APM is level.
  3. If you just stick the APM to the bottom or top of the fuselage it will not be level, which may affect performance.
  4. I don’t like to take chances, so, I removed some of the foam below the top inside of the fuselage to get the APM level:
../_images/APMcut_zps150b55d7.jpg

Component Placement

  1. Here is the APM set in place with some of the components.
  2. At this point you should mark where your access panel will be.
../_images/B137BD6E-0007-4519-A3B4-FA1D15830A1E_zpslonqajyc.jpg

Trimming the Fuselage

  • I originally cut too much and the fuselage was really weak.
  • No problem; with some hot glue you can easily fix any boo-boos.
  • In the picture below you want to cut the lower portion and leave the area I have labeled “Do Not Cut”.
  • You will have ample room to access the APM Inputs and Outputs, as well as the USB port and other pins.
  • Cut straight through the foam so that the panel will open easily.
../_images/Smallpanel_zps67fcb0d3.jpg
  • Now match up the two halves to mark the cuts for the right side.
  • Cut a larger access panel out of the other (right) half of the fuselage so you can access the USB port on the APM.
../_images/plane_bixler_build_cut_out_access.jpg
  • Cut a bevel along the long axis of the large panel we already cut out.
  • I think that my picture is incorrect below; make this cut on the panel from the right half of the fuselage.
  • This is not the edge where the two halves of the fuselage join, but the cut near the wing.
../_images/plane_bixler_cut_near_wing.jpg
  • Now, make a Welder’s glue hinge where the bevel (that we just cut) meets the fuselage.
  • This creates a hinge for the panel that is invisible and super cool.
  • Don’t worry, custom foamies use this type of hinge for hundreds of flights.
  • Here is link to a YouTube video explaining how to make a Welder’s hinge:
  • The panel should look like this when the Welder’s hinge is complete:
../_images/F00F7556-92C3-4270-A4E1-412098A35B86_zpsl7qmp921.jpg

Assemble the Fuselage

  1. So now I am going to fast forward a little bit.
  2. Follow the Bixler instructions and glue the halves of the fuselage together.
  3. Again, I use Welder’s glue, applying a thin bead to each half, letting them get tacky, and then assembling the halves.
  4. Run the motor cables from the ESC to the motor before you assemble the two halves.
  5. No worries if you don’t, but it will save you the trouble of trying to attach the motor leads with needle nose pliers and hemostats.
  6. You should also check the rotation of the motor so that you do not have to switch motor leads for a motor spinning in reverse.

COMPONENT Installation Details

  • Below I have the fuselage glued together and the components glued in place.
  • I like hot glue for this detail.
  • Notice that I glued a 3mm carbon fiber rod across the access hatch for added rigidity.
../_images/Componentlayout_zpsf49f6f82.jpg
  • At this point, space is becoming a concern.
  • You will notice that we have put nothing in the nose so far, and all of our components are pretty tightly tucked under the wing.
  • I did this so that we can utilize bigger batteries in future builds.
  • This time around I am using an airspeed sensor which is recommended, but not necessary if you are on a first-time build budget.
  • To make space for batteries, I mounted the airspeed sensor board and receiver to the bottom of the canopy hatch:
../_images/plane_bixler_airspeed_sensor_mounting.jpg

Complete The Construction

  1. Use a servo splitter cable for the ailerons, I got odd results when programming separate aileron servo on its own channel.
  2. I am quite happy with this setup because you can get the CG perfect with Zippy 2200mAh Lipo batteries.
  3. I mounted the GPS/Compass on the right wing after removing just a small amount of material.
  4. I mounted it with hot glue and taped the cables in place with 3M Blenderm tape.
  5. I like Blenderm because it sticks well and is flexible.
  6. Having it sitting up high on the wing is not ideal, but I wanted to get it away from the fuselage and all of the current-carrying electronics.
../_images/plane_bixler_compass_on_wing.jpg