CarbonCore Cortex....Owners' Thread

Mrtarango32

Mrtarango32

Member
CarbonCore Cortex Maiden Flight Completed

Wow. Now I'm having buyers remorse ordering the frame. With that type of attitude he's having towards you. It's crazy
 
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R

R_Lefebvre

Arducopter Developer
Well, has Quinton disassembled the system himself before as CarbonCore stated? If so, there must be some consideration that maybe he caused it?

Doesn't take away from the fact that tab-in-slot is a silly design. Does that screw simply "thread" or rather "bite" into the slot in the carbon fiber bulkhead?
 

Q

Quinton

Active Member
jes1111 said:
I feel for you - sounds like his previous employment was with British Gas or the local council ;)
Click to expand...

BTW Jes, thanks for the link to the bolts, I had 200 of each dispatched today for just £1.30, sure beats the £2.16 for 10 from CC
Also exactly what glue can you use on Carbon Fibre as I thought it was bad for it and weakened it?
Notice on the 3rd image that where the bolt comes through, the carbon fibre is also coming away slightly.

I also bought the Vulcan PDB 250A to see if I could use it with my new ESCs instead of the CC one, as the holes in it are really small, barely enough room for the 14 AWG wires to fit through and it is 2x100A boards laminated together to make 200A
Unfortunately the PCD is 40mm instead of the 45mm ones already there.
 

Q

Quinton

Active Member
R_Lefebvre said:
Well, has Quinton disassembled the system himself before as CarbonCore stated? If so, there must be some consideration that maybe he caused it?

Doesn't take away from the fact that tab-in-slot is a silly design. Does that screw simply "thread" or rather "bite" into the slot in the carbon fiber bulkhead?
Click to expand...

You have to take the top off, how else would you get the flight controller in.
That was 1 time, then I did it again, when my motors would not start to see what the problem was (after I could get the 2 bolts removed as they had rounded hex heads.
The screw I would imagine is supposed to screw into the CF, but looking at it there was no thread marks, maybe thats why he also uses glue.
The bottom plate comes pre-made to you by Carbon Core, with the ESCs and motors already in place with all the screws threadlocked (and possibly glued)
 

R

R_Lefebvre

Arducopter Developer
What a ridiculous construction technique. I'm surprised it holds together at all. And, well, I guess it doesn't. It's entirely possible for that little plate to flex in the middle, letting the screw come out of the slot, and then getting into the ESC as you've shown.

Was this damage on the top side of the ESC or the bottom?
 


Q

Quinton

Active Member
R_Lefebvre said:
What a ridiculous construction technique. I'm surprised it holds together at all. And, well, I guess it doesn't. It's entirely possible for that little plate to flex in the middle, letting the screw come out of the slot, and then getting into the ESC as you've shown.

Was this damage on the top side of the ESC or the bottom?
Click to expand...

It was on the bottom, picture no2 is actually upside down, I just took it that way to show that the thread had not even grabbed onto the slot.
This one was not even the one with the bad ESC, this one just came apart whenever I cut the cable ties.
I'm not sure what he is saying in his email, you can see that the hole is bang on center, no matter where the cable ties would have been tied (which he did) bang on center is where that bolt comes up from the bottom.
I actually flew this thing 3 times, twice without weight, then I added a 2.5KG weight, after it landed with a 9 mins flight the motors would not start again immediately after landing, then I took it home and attempted CSC, this is when the ESC went pop as all the motors weren't starting at the same time, and there must have been an excessive spike.
When I sent an email to him this afternoon showing him the picture, then I got that reply, so I have had enough.

I would love him to have a say in public, but I am not sure he would, as some of the emails he has sent me you would be amazed by.

One example is that I made the purchase, and received the FEDEX tracking notice, it said 3 days to get from UK to Uk (no idea why) I waited the 3 days, and then the tracking notice changed so it was supposed to arrive in another 10 days.
I called him up to find out what the problem was, he assured me that it was Fedex problems, and I would have to call them, as he did not have the time.
I called them, and they said the reason is because he did not pay for priority, (which he assured me he did) and I would have to get him to call them to change it, so I called him back, and wanted him to get in touch with them to change it to priority.
He emailed me back saying that its not possible and I would just have to wait, and anyhow that his web site was not up to date and I did not have to pay for the postage anyhow, so he didn't know why I was complaining.
I called FEDEX up myself, and explained to them again the situation, and funnily enough they delivered it that same day, even though the tracking said it would be the following Wednesday.
When I order things from England I "always" get them next day no matter what I buy.

I know this sounds like something out of Monty Python, and I have a hate campaign against him, but I honestly do not..I've just had it up to here with him, and the useless excuses.
 

J

jes1111

Active Member
He's obviously completely clueless about customer relations - acting like he's doing you a favour interacting with you at all - I hate that! And, as Rob says, as a construction technique that sucks big time! There is a common way (even though I don't rate it myself) to fix such a bracing piece perpendicular to a slotted surface - with a t-shaped cut in the piece dimensioned so that a nut sits within the crossbar of the t-shape - a screw from underneath will then pull the nut downwards, snugging the piece into its slots. That he hasn't utilised this simple technique indicates a certain "insularity" in his thinking. He evidently believes that his design is the greatest thing since sliced bread, hence the absurd "no pictures" nonsense.

Whether or not you decide to keep the frame, there's the obvious problem that long-term support/parts availability is unlikely since people like this tend to go out of business rather quickly.
 

C

cootertwo

Member
"Power to the people" If it weren't for forums like this, we'd never know who we were doing business with. He's screwed the pooch now. He could have gave back a little bit of his profit, in time and parts, and had a happy customer, and good reviews. It won't be long, and he'll have all the time in the world, to talk to anybody.
 

R

R_Lefebvre

Arducopter Developer
I don't even like that method Jes. A really easy and cheap way I make bulkheads where strength and stiffness aren't the most important: Take a piece of 1/8" plastic strip. Drill 2.5mm holes in it edgewise. Ram in some M3 screws. Done.

High strength bulkheads, nothing beats aluminum, drilled and tapped properly.
 

Q

Quinton

Active Member
OK Now I am making things completely public which I would not normally do as I try to respect people who sell online, as it can be quite hard, as he seems to be still pointing towards me being at fault, just received another email from him a few minutes ago which I am not happy with, as hes now saying that I broke the rules that was said in the instructions I was not to do.

Hands up here who does their maiden flight with 2-3kgs underneath..
I do hope he is not trying to play funny buggers as I will have trading standards down on him before he can say Cortex.
I have sold online for the past 12 years and I know what I can and cannot do, and I have always been reasonable with him..

Hello Quinton,

Your email says:
It worked fine, then stopped working correctly after you had landed. So, it was working fine.
Many customers have reported problems developing with the A2, after some flight time.

Can you please send a photo of the ESC instillation showing how a bolt was screwed in to the ESC, please.
ESC Plate M2 coming lose, maybe pulled-out by the top plate being removed, after repeatably dismantling, does not explain ESC M1 with the hole.

I cannot see how this was done by myself - the ESCs are fitted after the ESC Carbon plates are fitted and bolted and glued.
No bolts go in to the lower Cortex frame plate after electronics are fitted, with exception of the retract pin bolts.
The Carbon ESC plates are also tolerenced to just kiss the bolt thread, as the carbon is quite hard, and the set glue (residue) forms the thread.

Please accept my apologies if there were marks on some ESC cables - I deemed them OK as the insulation was in tact.

I do think the problems with flying were with the A2 controller.

Flying without payload is one thing that can damage ESCs - we discussed partial load.
The printed insert with your ARTF Cortex, the 2nd Warning under ESC Calibration Warnings: Quote:
"Warning: Do not fly the Cortex without any payload – ESC, motors, propellers and your battery (5-6S LiPo) are matched to lift payloads.
Operating the Cortex without payload puts the ESC under partial-load which is bad for them."

You have now written to say you have not observed one of the printed warnings,
and earlier to say you are fitting other ESCs, not tested by CarbonCore.

I am very sorry, I cannot provide support for the A2 controller (I recommended the WooKong) or electronics not purchased from CarbonCore.
You have done two serious things I have specially asked you to not do.

Learning to correctly build and fly radio controlled models is difficult and takes years to learn.
The learning curve is very steep and unforgiving. I am sorry you have had so much trouble: I do feel I have helped as much as I can.
You chose to disregard some of my most important advise.
The Option to Purchase an RTF - Test Flown Cortex was an option.

We will continue to read your emails, however we have now discussed and provided support on practically every aspect of the product with you.
Can you please send a photo of the ESC instillation showing how a bolt was screwed in to the ESC, please.

Very Best Regards,
 
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R

R_Lefebvre

Arducopter Developer
He could actually have a point with the ESC load thing. The mechanism is not entirely clear to me... ripple current or freewheeling current... something like that but heli guys have known for a long time to not run motors with high load and low throttle %. In your case, the load might seem to be low, except when the flight controller is jittering the ESC's for stabilization control. So they could be getting shots of mid-throttle and high load as they accelerate.
 

Q

Quinton

Active Member
R_Lefebvre said:
He could actually have a point with the ESC load thing. The mechanism is not entirely clear to me... ripple current or freewheeling current... something like that but heli guys have known for a long time to not run motors with high load and low throttle %. In your case, the load might seem to be low, except when the flight controller is jittering the ESC's for stabilization control. So they could be getting shots of mid-throttle and high load as they accelerate.
Click to expand...

Hes a heli guy, and I understand that completely, however I also fly a Skyjib Hexa super 6, with (3kg) and without load and the gains in the FC compensate for it.
I did ask a question in these forums regarding flying without load is this a true statement before I made the purchase (the statement was made from him.)
update* Just added a link to that statement..
http://www.multirotorforums.com/sho...-statement-regarding-ESCs&highlight=statement

I understand if its a freewheeling ESC that there will not be a problem, as it will not be turned into heat, but Im at 45% without load, and approx 65% with load, so I do not see the problem.
I am quite new to this, but I am also not stupid, I have done a lot of research, not as much as you obviously as I have learned a lot from your posts in other forums,.

He is using the instructions bit as an excuse that there is a problem with the ARTF setup.
Everything seems to be at fault except from his end, which I can not accept at this time, and if he held his hand up and said, well look, maybe there is a problem here, lets try and sort this out.
Its not money or compensation I'm after, I just dont like being looked down upon and told, look flying things is actually unforgiving...selling things that are not up to scratch is unforgiving.
Show me any multirotor distributor that has not even flown an A2, and wants to simply put the blame on the FC!
 
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R

R_Lefebvre

Arducopter Developer
If you were flying at 45% with no load, there should not have been a problem I would think, unless the ESC's were really cheap. I have a beater quad made with leftover Hobby King parts that flies at 30% load with no problem at all.
 

Q

Quinton

Active Member

J

jes1111

Active Member
He's talking out of his you-know-what about this "partial throttle" thing. Sure there are some issues (as discussed in the linked thread) but he should have speced the ESCs for a "mid-throttle" hover, i.e. around 50% throttle. I'm not totally sure, I might have to google it, but I think that 50% counts as "partial throttle" ;)

We should mention Carbon Cortex a few more times (Carbon Cortex, Carbon Cortex) so that google gets the right idea and directs people who are interested in the Carbon Cortex to this thread about the Carbon Cortex ;)
 


D

deluge2

Member
The possibility of triggering unintended Go Home or Failsafe is certainly something to be mindful of. And perhaps a more sophisticated approach to defining when the FC should *NOT* obey the command is feasible. However, keep in mind that this vulnerability only exists in the moments after the 'CSC' dual stick motor start command has been issued (Move both sticks to the same or to opposite lower corners) to start the motors. After that, if the throttle is not raised above 10% within 3 sec, the motors are automatically shut back down. So when the props are spinning slowly, the craft is armed and ready to obey take-off or RTH commands.

You make a good point (in later posts) that perhaps the FC should 'know' that RTH is not a reasonable command when the craft is on the ground. I wonder if FC manufacturers will build that in to their algorithms in the future. Considering the relative sophistication of DJI's 'smart' landing gear retracts behavior, perhaps they adopt a more intelligent implementation of RTH in future firmware upgrades.

Steve


jes1111 said:
<SNIP><SNIP>
<SNIP>
Also, this sounds worrying:
Quinton said:
<SNIP>

<SNIP>Oh and on a side note, the 1 switch go home on the A2, I'm not sure thats such a good idea. I am used to the Wookong, it was on the ground with the motors spinning, and I thought I was resetting my clock on the transmitter, and I forgot that switch now was the go home button...off it shot into the air to reach its 20 meters to try and go home, never put it into manual so quick in my life.
Click to expand...

I'm not familiar with DJI gear (also on my "don't shop there" list) but, if I understand you correctly, this is a serious safety issue - basically an "un-commanded takeoff"? Wow!
Click to expand...
 

Q

Quinton

Active Member
jes1111 said:
Check this out:
http://www.multirotorforums.com/sho...-in-Yorkshire-UK&p=63061&viewfull=1#post63061

Notice the text after the video :)
Click to expand...

Jes your bad :)
[FONT=&amp]"This video is without any payload."[/FONT]

I see hes not that long in the building game.
Believe it or not, hes actually quite a nice bloke to begin with, but its a bit like Jekyll and Hyde.
Again, i have learned a valuable lesson... BTW if theres anyone out there who would like to put some effort/time/money into designing/building a really good frame, Im all ears, maybe we could throw it up into Kickstarter :)
Kopterworx have it right with their hammer 8, (probably very simple, bUt IT WORKS) unfortunately they are not willing to sell their frame on its own, and I don't blame them, they have spent a lot of time resources seeing what works and what doesn't!
 

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