# UAS FOCUS, LLC

MAINTENANCE MANUAL

TechMerlin C8 Multi

- Rotor UAS

(3D Robotics X8 UAS)

This Document Must Be Kept, At All Times, With:

TechMerlin sUAS Serial Number:_____________

Date of Issuance:_____________

V. 7.2015_1Maintenance Manual

Page 2 of 11

V. 7.2015_1 

## Log of Revisions

Revision Information

Rev. # & Date Pages Revision Description

Signature

Printed Name & Title

Maintenance Certification

Department

Revision Date :____________Maintenance Manual

Page 3 of 11

V. 7.2015_1 TABLE OF CONTENTS

Section Page

1 Routine Maintenance Schedule 4

2 Interim Maintenance Procedures 4

3 Connect Flight Controller, Download Logs and Check for

Anomalies 5

4 Inspect all Frame Parts and Wiring 5

5 Check Motors 5

6 Update Firmware 5

7 Propeller Replacement 5

8 Calibration 6

9 Calibrate Radio Control 6

10 Select Flight Modes 6

11 Failsafe 6

12 Calibrate ESC’s 7

13 Test Motor Rotation 7

14 Test Fly 7

Appendix A

– Motor Replacement 8

Appendix B

– TechMerlin Air Worthiness Checklist 10Maintenance Manual

Page 4 of 11

V. 7.2015_1 Routine Maintenance Schedule for TechMerlin C8 Multi

- Rotor UAS

Routine maintenance interval on the TechMerlin C8 Multi

- Rotor UAS (“TechMerlin”) is

performed after every fifty (50) flight hours. The routine maintenance procedures begin on

page 5 of this Maintenance Manual.

Interim Maintenance Procedures

Between routine maintenance intervals, in order to maintain the TechMerlin in a safe and flight

worthy condition, it is our best practice for the Operator to perform the following procedures after

every ten (10) hours lf fight time:

1. Visually inspect the TechMerlin for any obvious maintenance issues. If any obvious

maintenance issues are noted, the TechMerlin should be taken out of service and

promptly returned to the Maintenance Department for the appropriate repairs.

2. Clean the TechMerlin, using compressed air to remove any dust or dirt which may have

accumulated on the aircraft.Maintenance Manual

Page 5 of 11

V. 7.2015_1 

### 50 Hour Maintenance Procedures

3. Connect Flight Controller

o download all logs

o check for anomalies

4. Inspect all frame parts and wiring for continuity

a. If any breaks are discovered replace the noted parts and any complementary

sub assemblies

5. Check all motors for proper operation . If motors are not operating properly, replace as

per instructi ons in Appendix A.

6. Firmware update to latest UAS Focus ratified firmware

o Update made via Focus Mission Planner

o Install firmware

Select your frame type to install firmware. Listen for the tone once firmware

installation is complete. You may need to perform the extra step below to

complete installation.

7. Propeller Replacement

o Supplies (8) Propeller adapters, (4) SF Propellers, (4) SFP Propeller

o Remove the rings from the propeller package. Select the ring with the smaller

internal diameter, and insert it into the back of the propeller hub.

o Select the propeller adapters and the longer screws provided with the

adapters. Do not use the x

- shaped plate. Apply threadlocker to the three small

screws included with the propeller adapters (less than one drop covering four

to five threads). Attach an adapter to the top of each motor.

o Your X8 uses SF and SFP propellers. These prop ellers are labeled on the

package and on the propeller itself. Add SF and SFP propellers to the motors

shown in the diagram below with the writing on the propeller facing towards the

sky. The right propeller order and orientation is critical for your copte r to fly

correctly. Add the spacer above the propeller, and secure the nut tightly on top.

This will be a tight fit; apply pressure and twist the propeller onto the shaft.

Important Note: Ensure that the writing on the propellers for both top and

bottom motors faces the sky.Maintenance Manual

Page 6 of 11

V. 7.2015_1 X8 propeller order diagram

8. Calibration

o Launch Wizard

 Calibrate accelerometer

Follow the prompts to complete accelerometer calibration. Make sure

to rest the copter in each position for a few seconds before moving to

the next position.

 Calibrate compass

Follow the prompts to complete compass calibration.

o Battery monitor

Select 3DR Power Module for both options to enable battery monitoring using

the power module.

9. Calibrate radio control

Ensure that your RC transmitter and receiver are bound before performing

calibration. Turn on your RC transmitter, and select Calibrate Radio. Select

Calibrate to start, and move the sticks and switches on your transmitter to all

possible positions. Check to see the red bars stop at the extremes of each control.

When each channel has a correct minimum and maximum limit set by the red bars,

select Click when Done to complete.

10. Select flight modes

Move the switches on the transmitter, and assign a flight mode to the green

highlighted ent ry for each position of the switch.

11. Failsafe

Failsafes are pre

- programmed behaviors that can be assigned to your copter in the

case of specific failure conditions. Configure or verify that throttle, battery, GPS,

and ground control station failsafes are se t per UAS focus specificationsMaintenance Manual

Page 7 of 11

V. 7.2015_1 12. Calibrate ESCs

With props removed, turn the radio on and set the throttle setting to maximum.

Connect the powers supply or battery, after a series of beeps the flight controller

will flash red, yellow and blue, confirming th at it is in calibration mode. Disconnect

the battery, after a few seconds reconnect the battery and wait for the beeps to

stop. Move the throttle position to the minimum setting and for two more

confirmation beeps. Now raise the throttle slightly and all t he motors should spin.

13. Test Motor Rotation

Once you have verified that the motors spin at the same rate, check the direction

of rotation for each motor: clockwise (CW) or counterclockwise (CCW). The motors

should spin in the directions shown below for X8

- m

Correcting motor rotation: If any of the motor rotations need to be reversed, undo

the steps of this build until you can access the connection between the motors and

ESCs. To reverse the order of a motor, switch two of the cables connecting the

motor to t he ESC. In the example below, one order of motor

- to

- ESC wiring

produces one direction of rotation and the other produces a reversed rotation.

clockwise rotation wiring

counterclockwise rotation wiring

14. Test Flight. Before returning the TechMerlin to service, perform a test flight and

complete the TechMerlin Air Worthiness Checklist contained in Appendix B of this

Manual.Maintenance Manual

Page 8 of 11

V. 7.2015_1 

## APPENDIX A

MOTOR REPLACEMENT

1 Assemble bottom motor

Align two holes in the bottom of the motor with two holes in the motor plate. Apply threadlocker to two 5 mm bolts, and secure the motor to the plat e from below. This motor will attach to the underside of the arm,

so orient the motor so that the cables will protrude as close as possible to the hole in the side of the arm. When applying threadlocker, use less than one drop, and cover only four or five threads where the bolt

connects with the motor. Make sure to insert the bolts into the holes in the bottom of the motor and not in to the slots where they could interfere with the motor.



### 2 Attach top motor to arm

Place a motor plate on top of the arm with the short end of the plate facing towards the end of the arm. Place the motor on t op of the plate, and align the t wo small holes in the motor, plate, and arm. Orient the

motor with the cables as close as possible to the hole in the side of the arm. Apply threadlocker to two 5 mm bolts (less tha n one drop covering four or five threads at the end of the bolt), and secur e the motor and

plate to the arm from below by accessing through the two large holes in the bottom of the arm. Make sure to insert the bolts into the holes in the bottom of the motor and not into the slots where they could

interfere with the motor.



### 3 T hread motor cables through the arm

Now you'll thread the cables from both motors through the arm. First, thread the cables from the top motor through the hole i n the side of the arm, and use a piece of tape to label the cables so that you can

distingui sh between the top and bottom motor cables. Once you've labelled the top motor cables, thread the bottom motor cables through the hole in the arm.Maintenance Manual

Page 9 of 11

V. 7.2015_1 

### 4 Attach bottom motor to arm

Place the assembled bottom motor against the bottom of the arm with the short end of the plate facing towards the end of the arm. Apply threadlocker to the ends of the two 25 mm bolts (less tha n one drop

covering four or five threads at the end of the bolt). Place a 19 mm hollow spacer between each of the pairs of holes in the two motor plates. Place the 25 mm bolts through the motor plates and spacers, and

secure from below with a metal nut.Maintenance Manual

Page 10 of 11

V. 7.2015_1 

## APPENDIX B

TechMerlin AIR WORTHINESS CHECKLIST

This checklist specifies the guidelines by which each TechMerlin is deemed airworthy prior to

being placed into service after routine maintenance . Each procedure is performed by the systems

technician and test pilot, and verified for quality assurance.

TechMerlin Serial Number: ________________ Test Flight Date: ___

_____________

Flight Location : _______

__________ _ Temperature: _____ (F) Wind Speed/Direction : _

______

I. Manual Flight Testing

1. Electrical Systems Verification

a. Magnetometer Calibration: Mag cal has been performed. _______

b. GPS: GPS system performance has been verified._______

c. Connectors: All connectors have been secured and function properly under load. ____

2. Mechanical Systems Verification

a. Blade Tracking: Blades are in track and system is balanced.______

b. Transmission: All transmission components have been inspected. Drive train has been

inspected for unusual wear during break

- in process, and alignment of components checked._____

3. Engine Functionality

a. Engine start has been tested ____ times and is working properly_____

b. Engine has been run for _____hours, successfully: _____

II. Auto

– Flight Testing

1. In

- Air Engagement: Aircraft has been engaged in auto with successful Navigation System

maneuvers performed in accordance to test plan

. 2. Max Forward Flight: Aircr aft has been tested at ________ k/ph

3. Auto Take

- Off: Aircraft has been configured for auto take

- off, and has performed _______ times

successfully. _______

4. Auto Landing: Aircraft has been configured for auto landing, and has perfor med _______ times

successfully. _________

III. Camera Platform and Camera (if installed)

1. Camera platform integration has been checked and platform performance verified_______.

2. ________________camera has been integrated and evaluated for in

- air performance

_______

IV. Full Gross / Full Term Flight

1. Unit has flown full term under full gross payload.______

. 2. Unit has flown ___ hours single flight duration, and ___ total h ours full term in

- air testing.Maintenance Manual

Page 11 of 11

V. 7.2015_1 CERTIFICATION

I certify that TechMerlin , Serial #__________, has been verified as flight worthy. All specifications have

been met and the unit is cleared for in

- service flight.

Pilot Signature Technician Signature Verified By Signature

Print Name Print Name Print Name

Date Signed: Date Signed: Date Signed: