DIY - ZMR H250 Quadcopter

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Information

This is the build log for my ZMR H250 Cloneout Quadcopter. This is the first multirotor I have ever attempted to build and as such it will be documented and treated as a learning experience. All of the information contained here-in has been gathered and processed into the information you see here.

Websites

• RC Groups : ZMR 250 (Blackout Clone)
• RC Groups : PDB for ZMR 250 Mystery Carbon Fiber Frame
• RC Groups : FrSky Taranis "Howto" Thread
• RC Groups : FrSky Taranis with OpenTX 2.0 and Beyond
• RC Groups : Afroflight Naze32 Setup Guide for Dummies
• RC Groups : Get Your Technician's License. It's Easy. Here's Why And How.

Parts List

Build Log

• Pre-Build Checklist.
  <img src="http://kyau.net/img/ZMR250/prebuild-1.jpg" width="259" height="194" alt="">
• Pull the frame and PDB out of the box.
  <img src="http://kyau.net/img/ZMR250/prebuild-2.jpg" width="259" height="194" alt="">

Motors

• Pull out all the motors, there are long and short screws (separate them).
  <img src="http://kyau.net/img/ZMR250/motors-1.jpg" width="259" height="194" alt="">
• Put the propeller shafts on the motors with 4 short screws.
  <img src="http://kyau.net/img/ZMR250/motors-2.jpg" width="259" height="194" alt="">
• Assemble the motors to the carbon fiber arms, use 2 long screws and 1 short for each motor (be sure to also seal with loctite). To determine which gets the long vs. short screws, look inside the motor at where the motor leads are attached. If the hole you are putting the screw through is above the motor cables you have to use the short screws so you dont short out the cables.
  <img src="http://kyau.net/img/ZMR250/motors-3.jpg" width="259" height="194" alt="">

Battery

• Plugged in the soldering iron (medium tip) to get it hot to solder the battery connector to the PCB.
  <img src="http://kyau.net/img/ZMR250/battery-1.jpg" width="259" height="194" alt="">
• Took this time to start charging one of the batteries I bought for the quad.
  <img src="http://kyau.net/img/ZMR250/battery-2.jpg" width="259" height="194" alt="">
• Soldered the connector to the board.
  <img src="http://kyau.net/img/ZMR250/battery-3.jpg" width="259" height="194" alt="">

ESCs

• Strip the sticker and current heat shrink off of the ESCs.
  <img src="http://kyau.net/img/ZMR250/esc-1.jpg" width="259" height="194" alt="">
• Repeat this for all four ESCs.
  <img src="http://kyau.net/img/ZMR250/esc-2.jpg" width="259" height="194" alt="">
• Plug the soldering iron back in (fine point tip).
• Desolder all of the motor leads from all four ESCs.
  <img src="http://kyau.net/img/ZMR250/esc-3.jpg" width="259" height="194" alt="">
• Cut the motor's lead wires to length for placement of ESCs on arms. Then solder the ESCs to the motors, remember to connect two in a 1:1, 2:2 & 3:3 configuration and the two other motors in a 1:1, 2:3 & 3:2 configuration.
  <img src="http://kyau.net/img/ZMR250/esc-4a.jpg" width="259" height="194" alt=""><img src="http://kyau.net/img/ZMR250/esc-4b.jpg" width="259" height="194" alt="">
• Finally we need to test the motors, for this i used the original ESC leads that we de-soldered previously and soldered two of them to one of the spare battery connectors I had to act as a wire harness to be able to spin up the motors with the receiver and transmitter. This allowed me to mark on each which direction they spin so I can make sure i have two CW and two CCW motors. If not go back and resolder your ESCs accordingly.
  <img src="http://kyau.net/img/ZMR250/esc-5.jpg" width="259" height="194" alt="">
• Heat shrink the ESCs to protect them from the carbon fiber.
  <img src="http://kyau.net/img/ZMR250/esc-6.jpg" width="259" height="194" alt="">

PDB

• With the ESCs prepared lets move on to the Overcraft Power Distribution Board. First you need to solder 2 separate servo leads, one for the vbat and the other for the buzzer. Make sure to cut them to length before hand or you will be re-cutting/re-soldering like I had to.
  <img src="http://kyau.net/img/ZMR250/pdb-1.jpg" width="259" height="194" alt="">
• Mount the flight controller onto the PCB using the nylon standoffs.
  <img src="http://kyau.net/img/ZMR250/pdb-2.jpg" width="259" height="194" alt="">
• Attach all of the arms and the bottom plate using only 2 out of the 4 screws on each for the time being. Then pre-tin the pads on the PDB for the ESCs.
  <img src="http://kyau.net/img/ZMR250/pdb-3.jpg" width="259" height="194" alt="">
• Cut down to length and solder all the ESCs to the PDB.
  <img src="http://kyau.net/img/ZMR250/pdb-4.jpg" width="259" height="194" alt="">
• Cut the power and ground off of ESCs 2-4, leaving the BEC only giving power to the flight controller from one motor (for this I chose motor #1). Then connect all 4 of the motors to the flight controller (motor one starts at the arrow then they count up). You can also connect your receiver at this time (in CPPM mode) with a 3-pin connector as I have in the photo. Plug in the battery to verify all is well (you should hear a series of beeps out of the flight controller).
  <img src="http://kyau.net/img/ZMR250/pdb-5a.jpg" width="259" height="194" alt=""> <img src="http://kyau.net/img/ZMR250/pdb-5b.jpg" width="259" height="194" alt="">

Flight Controller

• Install the USB Driver for the flight controller. If you lack the driver for the Naze32 you can download it here.
• Make sure you have Google Chrome installed, and install the App Baseflight.
• Launch Baseflight and then connect your flight controller to your computer via usb (with the quad powered off).
  <img src="http://kyau.net/img/ZMR250/fc-1.jpg" width="243" height="165" alt="">
• Baseflight will not auto-connect the first time, click on the "Firmware Flasher" and make sure the latest firmware is chosen. Next select "Load Firmware (Online)" and then finally "Flash Firmware". Wait a few moments for your flight controller to update and then click the "Connect" button in the upper left, you should now be connected to your flight controller.
• Navigate to the "Configuration" tab and enable the features: PPM, VBAT, MOTOR_STOP & TELEMETRY according to the screenshot and then click "Save".
  <img src="http://kyau.net/img/ZMR250/fc-2.png" width="243" height="165" alt="">

Pre-FPV Stopping Point

• With the quad now fully working (aside from FPV gear) you can now check the battery voltage alarm by taking it on your maiden flight and running the battery down to low in a hover.
  <img src="http://kyau.net/img/ZMR250/pre-fpv-1.jpg" width="243" height="165" alt=""><img src="http://kyau.net/img/ZMR250/pre-fpv-2.jpg" width="243" height="165" alt="">

Videos

Mobius Maiden Flight

References

• Naze Wiki: Howto FrSky Telemetry
• Sky Scratch: Using FrSky Telemetry with Naze32 and Cleanflight using softserial