The QAV series of airframes utilizes a separation of the airframe into "clean" and "dirty" sections. This manual will walk through the assembly of a typical QAV 'dirty' frame. Please note that this manual applies equally to the QAV400, QAV500, and QAV540G airframes, but the pictures of parts are from a QAV400 build. Your frame plates or arms might look slightly different if you are working on a different airframe than a QAV400. But the building steps are identical.
Attaching the arms
- Parts needed: Four motor arms, 16 button head socket screws, Power Distribution Plate (also called PCB Plate) to which you will solder your ESCs.
- Tools needed: Allen wrench and blue thread lock.
- As shown below, place the PCB frame plate with the electrical pads facing down. Then place the motor arms next to the frame flat sides facing up, and the wire grooves facing down.
- See next image...
- Slide the arms underneath the PCB Plate and align the bolt holes with the outer 4 bolt holes, then apply thread lock to the screws and fasten them. The 2 images below show correct placement.
- The 3 images shown below are for reference only, and shows other capabilities of the QAV400 frame.
- Below you can see the ability of placing the QAV500 motor arms on the QAV400 frame. This gives the QAV400 the capability to run 10" props instead of 8" props supported by the black QAV400 arms.
Attaching the spacers
- Next, we put 10mm spacers on the PCB plate. You will need button head screws, and the 10mm spacers your kit came with. Make sure you use your blue thread locker again.
- The 2 images below show the correct placement, and screws pointing to the holes used.
- Also, see the illustration for the location of the frame's Center of Gravity.
Attaching the ESCs
Take the power distribution board ("PDB" or "PCB") and solder the ESCs to the connections marked by "ESC1" through "ESC4". Please note that this is how QAV frames numbers ESCs. This numbering will not match up with how a flight controller numbers the motors. Make sure you solder all the red wires to the "+" pads and all the black wires to the "-" pads. You want the power cables to be fairly short. Take a look at the picture below. The best way to assemble the motor/esc is by soldering the motor cables directly onto the ESCs. This will save you a lot of build time if your motors and ESCs don't already come with bullet connectors. It also will remove one of the key failure points on any multi-rotor. Bullet connectors can loose connectivity mid flight or one of the many solder connections that bullet connectors introduce can get weak and fail. If you do solder the motor wires straight onto your ESCs, make sure you shorten/lengthen your motor cables to an appropriate length and that you test each ESC/motor to ensure the motor spins in the right direction for where it will be located on the frame.
Attaching the Lipo Pig-Tail
Solder a lipo pig-tail (not included with QAV airframes) to one of the pads with the "Bat1" or "Bat2" labels. Turn the PDB so that the pig-tail comes out on the side that will work best with your lipos. If your lipos have the power leads on the right side, make sure the pig-tail comes out on the right side as well. You can attach the pig tail with a zip tie to the PDB. This ensures that in the event of a crash the pig tail will not be ripped off the pads and damage the PDB. Also, as an aside, please know that the PDB is fully symmetrical. It does not matter which side will eventually face forward and which one faces backward.
Other Power Leads
The PDB of QAV airframes provides you many additional power pads. Use these to attach power leads for your FPV equipment, lipo meters, sensors, cameras, LEDs, etc. as needed. We often solder a JST pig-tail (not included with QAV airframes) to one or two of the extra pads and run them up into the clean frame to make hook-up of FPV gear easy later on.
- We will proceed building without the electronics for better illustration purposes.
Close the Dirty Frame
- Time to place and attach the bottom frame plate of the lower "dirty" section. Before closing the frame, you might want to re-check that all motors are spinning in the appropriate direction.
- You will need the bottom frame plate (same size as PDB), and button head screws. Te next 2 images show proper placement.
Attaching Vibration Mounts ("Orange RC Bobbins")
- The vibration mounts are what separate the "dirty" section and the "clean" section. They are a vital part of the proper functioning of the QAV airframe series.
- You will need 4 of the Orange Vibration Bobbins and 4 M3 nuts, a 7/32 or 5mm socket driver and thread locker. The mounts will be placed on the two front and two back holes located on the PCB frame plate.
- The 2 images below show correct placement.
- When tightening the nuts, make sure you do not twist the orange vibration material, it can sheer off! Use a tiny bit of thread lock on the threads of the studs to secure the nuts.
Congrats! You're done with the dirty frame!
See below of how the dirty frame is later combined with the clean frame.