CarbonCore Cortex Upgrade Thread + Frame offer for the UK

[CarbonCore Multicopter]

Hello! This is Adele & Cameron at CarbonCore!

In this thread we are going to check-over and have a look inside a Cortex for your interest!
And we will be adding some new parts to it soon...
We';re only going to check this thread once a week.
If you need frames, parts or a little help, please contact us through www.CarbonCore.com

We really want to stimulate drones and Multicopters in the UK, so we';re proud to announce that we are now offering Cortex Carbon Airframes to the UK for £550 + VAT + P&P
We';ve made more than before and have just finished quality controlling and packaging a lot of them! - Please see the CarbonCore Cortex Build Thread for more info.
If you would like a Flight-tested Cortex like this one, or one made specially to your order, please contact one of our Resellers, who build and fly them all the time. www.CarbonCore.com/Resellers

The two sets of photos are of the one and the same Cortex, but in the "office" pics, 60mm pilars were added to lower the gimbal... more later! :)

More photos and info to come!

[CarbonCore Multicopter]

Photos of the underside with all the receivers and aerials. The metal plates around the gimbal pan motor were separated, and bolted back together with 60mm pillars in between.
This lowers the gimbal down a bit, helping the view. Props also removed and placed out the way with all fittings. This makes it much easier to thoroughly look at the propellers for any damage, and makes the copter much easier to work on.

[CarbonCore Multicopter]

Looking over the Cortex for any damage, anything missing or coming undone.



4x red thumb grips, 4x M3x10mm and 16x M3 x 6mm bolts all removed from the top plate, and set to one side. We';ve done a few flights with NONE of the top bolts glued-in.
They';ve been checked before and after every flight and none seem to have come lose.

[CarbonCore Multicopter]

Top plate off. The extra XT60 connectors on short cables going through the frame plate was Lou';s idea, at www.FutureSkyFilmSolutions.com  Lou builds lots of these.
And there';s the inside with all the wires. Wookong at the back and sensor at the front.

[CarbonCore Multicopter]

Better view of the sensor and a look at the motor cables going through each arm.

[CarbonCore Multicopter]

In these pics we had a close look at the regulators.
We included the "blank" frame plates so you can see the cutouts to indicate where the wookong and sensor can go.

And there';s a little hole in the front of the wkm sensor.  We';re wondering if this is the barometer.
Customers have been saying that the Cortex gets "altitude drop" when slowing down to hover. This might be how the air is going past the edges of the cortex frame plates and hitting the sensor. So, we';re going to read some more about this, and also try a cardboard or carbon panel around the sensor to see if it makes any difference on the next flight.

[CarbonCore Multicopter]

We';d like to add this video of exactly how this Cortex flies. And we';re going to fly it some more tomorrow and then we';ll have some more videos to share.

Regarding the sensor - we';re going to try some bench tests this afternoon, check the sensor mounting, re-calibrate the compass, double-check the vertical centre of gravity, and check the settings in the assistant software while the props are off. And generally check everything for flying tomorrow! 
https://www.youtube.com/watch?v=x-UGUKivadk

[Gaza07]

To embed your video on the forum just take the s off the https link you used 

[CarbonCore Multicopter]

We selected the Cortex 5D memory on the transmitter, switched on and powered the copter with a single 6S 22.2V LiPo pack.
Checked the retracts and they';re working.
All the motors (with props-off) start and stop at the same time, and sound OK.
The sensor is mounted on 1.5mm foam and is very well stuck. and has a little free-movement with the foam tape. We';re wondering if 3.0mm foam tape would be better.

Control Stick Command (CSC)(we just move the Tx sticks to the low corners) and the motors start*
*They will stop after 10 seconds if the throttle does not exceed 10%.
The motors on this Cortex stay at idle if the Tx throttle stick is between 10 and 50%, and only speed up after 50% - the stick is over half-way. So we will check the control monitor on the setup assistant.

Lifting the Cortex up, the sound of motor tone goes down,
and lowering the Cortex, the motor tone goes up.
And with pitch, roll and yaw the motor tones also change in a way that makes sense.

We held the sensor and moved it about these axis, and the motors reacted the same as if we were tilting the cortex.
And we squeezed the sensor as this would change the damping, and there was no changing in the motors.

And also, we used an hair dryer to copy wind blowing on the front of the WooKong sensor - and the motors DO also react as if the Cortex is being lifted up or down.

Blowing directly on it speeds up the motors.
Changing the angle of the air gave random results - both speeding up and slowing down.

Then we noticed, that with the Cortex sat there at just above half throttle, all the motors were all changing speed together!!!
Over about 5 to 10 seconds, they would all speed up slightly, then all slow down slightly... And they';d keep doing this.

So the Barometer seems to be working but we';re not sure if it';s right. Maybe it doesn';t like were it is in the frame, and putting some foam or a barrier in front of it will help or fix this behaviour. Maybe a firmware update will make a difference. Maybe it';s got dirt in or it';s broken...

Our main concern is the motor speed changing with the Cortex sat still on the bench. This might not be the WooKong sensor / barometer sensor. But might be a GPS problem. The motor speed did NOT change when we lifted the GPS independently of the Cortex. We';ll try more tests starting with the assistant panel and also a block of foam in front of the sensor to change how the air arrives at it.

[CarbonCore Multicopter]

We tried the hair dryer again on the sensor, this time with sponge in front of the sensor, and the results didn';t change.
Then we tried tape, covering the hole.
And there was no noticeable change in collective motor speed when the air was applied as before.
But, the motors are still all changing speed slightly, with the WKM sat still. And together every 5 to 10 seconds. Implying there are going to be small altitude variations in flight. Maybe the Altitude gain is too low?

And then we found, that the motors all react normally, with the tape on, when the Cortex is vertically lifted-up and down. As in the first test. The motor tones sound the same as without the tape.  But with tape, the air flow on the sensor is not changing the motor speeds.

SO we';re hoping this suggests the sensor will now only allow altitude to change the collective motor speed, and NOT airflow going on the sensor. Because after all we';re sure it';s an altitude sensor, NOT an airspeed sensor to change the altitude depending on the airspeed!

[CarbonCore Multicopter]

We';re making a point of NOT going into the firmware today - We';re going to put it back together and go flying!
And then hopefully show you some photos and videos!

We';re avoiding making more changes so we can see if there are any results from applying tape to the hole on the sensor.

If we change the gain and it flies differently, we';re not going be able to distinguish if it was the gain or the tape.

[CarbonCore Multicopter]

RESULT!!!!   

We added sellotape over the sensor hole on the WooKong, after trying some bench tests in the above post:  And it flew very nicely! 

We were advised, by two independent people, that the altitude sensor will NOT WORK if we cover that hole... We were also told it flies terrible if it gets dirt in.

Our bench test with props-off showed the motor tones to be about the same (by ear) when lifting and lowering the Cortex, with and without tape. So based on that we went flying!

And it was nice!  There is still a small variation in altitude but nothing dramatic, and it certainly cannot be compared to having to actually manage the throttle/collective on a helicopter.
It just needs the occasional touch of up or down.

This Cortex now flies as if we just need to turn the altitude gain UP a little...
We also noticed that the motors will only accelerate above idle when the transmitter throttle stick is moved above 50% after CSC...
But in-flight we are often between 10 and 50% throttle... so we';re guessing it must be calibrated OK.

We';ve also heard that some flight controller versions of firmware will NOT WORK in an X8, and other firmware versions for the same FC work EVEN BETTER than the version we';re flying with...

Newer versions of the WooKong also have this little hole in the side of the sensor... not the front...

But for the next flight, we';re going to leave the tape on the sensor, and now re-mount and re-calibrate the GPS to see if that 100% locks-in the altitude.

So we';ll do a bench test first, again lifting and lowering the Cortex with propellers off, and motors running, this won';t tell us when the gain is too high, because without props it';s not ever going to oscillate, or "hunt". We';ll be looking for the motors reacting a little quicker.



And we';re just uploading the Aerial Footage from the 5D ;D
- This flying site is anything but flat - it';s a very interesting place to fly!
- But really, for testing how and when there are any changes in altitude, we will fly a at flatter field :)

[CarbonCore Multicopter]

Here';s the aerial footage from our test flight :)
We forgot to start the countdown timer so just guessed the flight time and landed short - so we got 15 mins instead of the usual 20.

http://youtu.be/s4jDsaeITOA

[CarbonCore Multicopter]

More flying today!  We got some video of the Cortex 5D cruising about. And we';ll share it soon!

And we flew somewhere much flatter today.

[CarbonCore Multicopter]

We made a classic mistake and didn';t check all our equipment before we went flying!...

The 5D was on some other settings - not the right settings for AP!

So, we can share the video but put your sun glasses on! 

[CarbonCore Multicopter]

Ground-to-air video of the Cortex with 5D cruising around.
This is a practice flight and we';re just going to fly it some more deciding how to change the gains.

http://youtu.be/cv6CxzeeIk4

[flytahiti]

nice fly, could you share the gain you use for that setup

[CarbonCore Multicopter]

The Cortex setup with WooKong, Z15-5D and 5DMkIII

○ Atti Gains 200-200, Basic gains 100-100, Tx expo 30%, dual rates 50%.
○ CarbonCore Motors 4010 370Kv with short, coloured wires the right length.
○ 2x 6S 10,000mAh LiPo packs (20Ah @ 2.86Kg)
○ DJI WooKong-M Flight Controller 5.26 firmware
○ RD921 Receiver (0.024Kg)
○ DJI Z15-5D Zenmuse (1.42Kg)
○ Zenmuse mounting: 2x 12mm x 190mm Carbon tubes
○ Canon 5D MkIII with standard SD card and battery + EF 24mm f2.8 lens (1.24g)
○ 8.66Kg Complete flying weight
○ 20 minutes flight time consuming 17,600mAh (88% battery)
○ 58.6 Average current, 7.3A per motor. - This includes FC
...& Z15 current consumption
○ 6.7A per Kg
○ 150 Watts per Kg

[flytahiti]

Thank you very much , what about vertical Gain ?

[flytahiti]

Thank you very much , what about vertical Gain ?

[Desmoboy]

Is that weight for the canon correct ? looks very high. Perhaps the lens is very heavy.

[quadfather]

Yeah, that doesn';t add up.  It seems right for the combined weight of camera, lens and gimbal though.

Sent from my mobile

[CarbonCore Multicopter]

Updated the camera weight to 1.24Kg including the lens. Thanks for pointing that out! The All Up Weight and Amps/Kg have not changed.
The flying weight came off the scales of the complete aircraft with camera, gimbal and everything.

We';re going to add some more weight now in the form of a full carbon shell :)
We';re hoping this shell will also keep the air off the flight controller and solve the altitude drop problem.
Failing that it';s a firmware of flight controller change  ;D

Next to fit a shell and re-calibrate the GPS.
Note to self: Re-post Assistant Firmware settings.

[CarbonCore Multicopter]

Here';s the new CarbonCore Shell for the Cortex.
There';s space for 2x 10,000Mah 6S packs at 60 x 90 x 190mm approx.
GPS will simply be mounted on top at first with the PMU on the top plate.

[CarbonCore Multicopter]

Recently I';ve been trimming and finishing these shells myself. These one';s are sold already but there';s also a new webshop in the works that will have a wishlist and allow pre orders.

[CarbonCore Multicopter]

Hasn';t the weather been amazing this week!  We';ve been flying a few times and have some new 5D aerial footage to edit into a video for you!
Here';s this Cortex with WooKong and Z15 5D flying again - last flight log entry before getting a shell!

[CarbonCore Multicopter]

This Cortex has now sold.
I meant to make a screenshot of the DJI WooKong Firmware Assistant before it went but the gains are posted above.
I';m going to be building more like this 

And starting a new thread for a start-to-finish Cortex upgrade build.