Hi there,
my first post here :) Just want to share this build log of my first DIY quadcopter frame in carbon fiber.
Setup
- APM with GPS and Magnetometer
- 25cm Arms
- 54cm from Motor to Motor
- 18Amp HobbyWing ESC
- 750kv Motors
- 10x4.5 Props
- Turnigy nanotech 2200mha 25-50c
Extras
- HobbyKing camera with mount
- Fatshark 5.8Ghz 100mw video transmiter
Weight
- 640gr only the frame, motors and escs
- 980gr Total with the Video transmitter (not in the pictures)
Is this a good weight for this frame size and config?
About the build
I used CF 1.5mm sheet and CF tubes with 13mm diameter, to mount the motors i drilled the holes directly in the CF tube and used some plastic prop adapters to reduce vibrations. I also used some thin double side foam between the arms and top plate this way the arms will not be in direct contact with the CF plate, don't know if it helps or not. To hold the APM board the the frame i used the same double sided foam, i used 2 pieces on top of each other to give it a bit more height.
I intend to use this frame at first for some FPV, i used 8mm CF square tubes to make a camera mount, it looks pretty cool :)
I could save some grams in the wiring, but in this first step i decided to keep the wires in its original length for later changes, right now its a mess of wires between the 2 main center plates.
Some things i noticed after the build and 2 short test flights:
I thought that it was a good idea to drill the holes in the CF tubes and mount motors directly on it, actually the tubes can handle the screws even very tighten, they didn't crack, but its hard to get perfect hole alignment without proper tools. I used an aluminum profile 15x15mm, inside diameter was 13mm exactly the outer diameter of the CF tubes, i easily drilled the holes in the aluminum profile to serve as guide and inserted the CF tubes inside. It worked pretty well, but the inclination was not so good, it's hardly noticed but motors have some minimum inclination.
I'm afraid this inclination error will affect the stability, anyone has something to say about this? I'm thinking in changing the arms to aluminum square profiles or get some mounts like Heli tail booms, it would be easy to adjust inclination.
I didn't tune PID's yet, so first flights were a bit unstable, also i wonder if having the plates stacks too high can affect the stability as well.
Also the arms look nice when short close to the motors, but will be a problem if it crashes, and i'm sure it will :(
Here are some pics of the build, Cheers!
Comments
Hi @denorman, i din't touch PID much yet,
but here are my settings:
NOTE: 23.11.2011 12:31:21 Frame : + | Arducopter Kit | Kit motors
ALT_HOLD_RTL,1000
BATT_CAPACITY,1760
BATT_MONITOR,0
CAM_P_G,1
CAM_P_MAX,1900
CAM_P_MIN,1100
CAM_P_REV,1
CAM_P_TRIM,1500
CAM_R_G,1
CAM_R_MAX,1900
CAM_R_MIN,1100
CAM_R_REV,1
CAM_R_TRIM,1500
COMPASS_DEC,0.332
ESC,0
FLOW_ENABLE,0
FLTMODE1,0
FLTMODE2,0
FLTMODE3,2
FLTMODE4,5
FLTMODE5,6
FLTMODE6,0
FRAME,1
HLD_LAT_I,0
HLD_LAT_IMAX,1200
HLD_LAT_P,0.3
HLD_LON_I,0
HLD_LON_IMAX,1200
HLD_LON_P,0.3
IN_VOLT,5
LOG_BITMASK,382
LOW_VOLT,9.6
MAG_ENABLE,1
NAV_LAT_I,0.25
NAV_LAT_IMAX,2000
NAV_LAT_P,3
NAV_LON_I,0.25
NAV_LON_IMAX,2000
NAV_LON_P,3
RATE_PIT_I,0
RATE_PIT_IMAX,1500
RATE_PIT_P,0.145
RATE_RLL_I,0
RATE_RLL_IMAX,1500
RATE_RLL_P,0.145
RATE_YAW_I,0
RATE_YAW_IMAX,5000
RATE_YAW_P,0.13
RC1_MAX,1918
RC1_MIN,1101
RC1_REV,1
RC1_TRIM,1500
RC2_MAX,1919
RC2_MIN,1086
RC2_REV,1
RC2_TRIM,1500
RC3_MAX,1918
RC3_MIN,924
RC3_REV,1
RC3_TRIM,1500
RC4_MAX,1918
RC4_MIN,1085
RC4_REV,1
RC4_TRIM,1500
RC5_MAX,1919
RC5_MIN,1083
RC5_REV,1
RC5_TRIM,1500
RC6_MAX,1900
RC6_MIN,1100
RC6_REV,1
RC6_TRIM,1500
RC7_MAX,1900
RC7_MIN,1100
RC7_REV,1
RC7_TRIM,1500
RC8_MAX,1900
RC8_MIN,1100
RC8_REV,1
RC8_TRIM,1500
SERIAL3_BAUD,57
SIMPLE,2
SONAR_ENABLE,0
SR0_EXT_STAT,0
SR0_EXTRA1,0
SR0_EXTRA2,0
SR0_EXTRA3,0
SR0_POSITION,0
SR0_RAW_CTRL,0
SR0_RAW_SENS,0
SR0_RC_CHAN,0
SR3_EXT_STAT,0
SR3_EXTRA1,0
SR3_EXTRA2,0
SR3_EXTRA3,0
SR3_POSITION,0
SR3_RAW_CTRL,0
SR3_RAW_SENS,0
SR3_RC_CHAN,0
STB_PIT_I,0.001
STB_PIT_IMAX,156
STB_PIT_P,4.6
STB_RLL_I,0.001
STB_RLL_IMAX,156
STB_RLL_P,4.6
STB_YAW_I,0.01
STB_YAW_IMAX,800
STB_YAW_P,7
SYSID_MYGCS,255
SYSID_SW_MREV,111
SYSID_SW_TYPE,10
SYSID_THISMAV,1
TB_RATIO,0.92
THR_ALT_I,0.01
THR_ALT_IMAX,300
THR_ALT_P,0.5
THR_FAILSAFE,0
THR_FS_ACTION,2
THR_FS_VALUE,975
THR_MAX,1000
THR_MIN,0
THR_RATE_I,0.1
THR_RATE_IMAX,50
THR_RATE_P,0.6
TRIM_THROTTLE,476
TUNE,0
WP_INDEX,0
WP_LOITER_RAD,-24
WP_MODE,0
WP_MUST_INDEX,0
WP_RADIUS,3
WP_SPEED_MAX,400
WP_TOTAL,0
XTRACK_I,0
XTRACK_IMAX,10
XTRACK_P,2
XTRK_ANGLE_CD,3000
I changed the PID settings with out saving the default, would you be willing to post the default or your PID settings for stabilized and rate for pitch and roll.
I could use the help, and your success makes me jealous ;D
@Al Billings - i used cheap hxt500, they work pretty well.
@denorman - :) yep, i flew it just for testing last week, but today i flew it a lot. Without changing default PID it flies pretty good, I did some PID fine tuning to it, but it can go better. And i have an issue i have to fix, the arms have some inclination/twist its very very little but enough to mess with yaw :( left works fine and fast, right it takes 3 times more to yaw, i plan to replace the arms with aluminum profiles, for now, until i find a better way to mount the CF tubes.
@Yusuf - what do you mean??
@Mike - about your question of the video interference, there is some interference but not much, I'm a bit new in APM and i went to the field unprepared, i could not find a way to check real time data from the GPS to check for satellites, but from my results, it was quite the same with and without video transmitter. Btw, in my case the Loiter has a error margin of about 3~5 meters altitude is about 1.5 meters.
Cheers!
How do you do yawing on the copter??????????
have you flown it yet? What was PID tuning like.
I am coming from a multiwii and a hoverfly pro and this PID tuning is the hardest and worst of the 3.... by far.
eek!
I love your quad, it looks great!
Thanks! What servos did you wind up attaching to it? Have they worked well?
@Al Billings - I used a simple HobbyKing Sony CCD camera with this camera mount
I'm just using the Tilt, and to attach it to the frame i used double sided foam tape, this is a temporary solution, i plan to develop this frame design further and add a custom gimbal for a GoPro camera.
Cheers!
Hi guys,
Here are some more pics that will answer some questions.
I couldn't find where i put the aluminum profile with the holes i used as a guide to drill them in the CF tube, but here is a picture of the aluminum profile i used.
Basically just drill the holes in the aluminum and then insert the carbon fiber tube inside.
The carbon fiber tube i used is pretty strong due to its thickness, its 1.35mm thick but its very light as well.
1000mm long 13mm diameter weights
only 78gr.
Here are the tools i used to cut/saw and drill, i also use some clamps to secure the CF sheet, and to make the cut straight i used a metal rulers clamped on top of the sheet as a guide.
I have a Dremel that i could use, but in this project i could not use it because of the dust, the hand saw makes much less dust.
And here is a picture with the video transmitter
Thanks Sergio. I thought maybe spreading the COG out might be a problem but the ESCs are light.
I want to know the details about your camera rig. I have a small CCD from DIYDrones and I just ordered a Fatparrot display for my head but I haven't figured out how to mount the camera yet.