Build thread: KRATOS from Flexacopter.....Ultimate Octo-Copter

[ChrisViperM]

This is my first build thread ever since I hate to build, take pictures and write at the same time......but this time it's different.

As some of you know, there is a thread for quite some time now, where a guy (Mario) and his friends from Holland wanted to create the "ultimate" octocopter, the KRATOS.....Pretty big statement, but as I followed the progress of Kratos, I became more and more fascinated by the design, the technical details and the dedication of

the creators of Kratos.

The original thread: http://www.multirotorforums.com/sho...-octocopter-quot-KRATOS-quot&highlight=kratos

After a while I couldn't hold it any more and asked them for a quotation. Althought they had a "costs no limit" claim, I was surprised that the price is in the same bracket like a Cinestar 8 (in the meantime pretty outdated) and a Droidworks SkyJib.


I ordered (everything was supplied by Flexacopter) :

1x Kratos - Mainframe already assembled, arms, landing legs, mounting plates for Cinestar 3-Axis gimbal + Zenmuse Z15

8x Plettenberg Orbit 15-24 http://www.plettenberg-motoren.net/...s/plettenberg-brushless-motors/orbit/orbit-15

8x ESC TMM-6026-3 from ComPro - no Chinese rubbish (flash-able and programmable via PC interface) http://mgm-controllers.com/index.ph...controllers-tmm-6026-3-x-series-32-bit-system

6x Gensace - 6S-8000 mAh

1x custom made transport box for the Kratos

1x custom made transport box for the Cinestar 3-Axis gimbal


Parts I already have at home for the build:

Cinestar 3-Axis Gimbal + Radian stabilisation

Zenmuse Z15 for Sony NEX-7

Flight Control: ZeroUAV YS-X6

....lots of other stuff which will show up during bthe build.


The reason for choosing the ordered componets is that Mario has prooven that they work and the fact that, because of his extensive documented testing, I can save a lot of time with the set-up.....didn't want to use "Fly-Away" stuff from DJI anyways


I had a lot of questions in the beginning about the Kratos and it's components, but everything was always answered within a day max, and that didn't change after the deal was done. Very seldom you come across so pleasent people like Mario, and I am glad I did......


Finally I got the message (shipment of my order was delayed because I never had the time for the build and wanted to get the custom-made cases) that they are shipping now. Since I am always an unlucky guy, Kratos arrived just when I had to go to the airport for a business trip. Took a whole week to open my parcel.


Following are some pictures of the parcel and it's content:

When ever I got some time, I will update this thread with the progress of the build....now it's time to go to bed.


Chris

 

[holco]

Hi Chris,

Good luck with your build and flying of the Kratos, wish you many happy hours with it :tennis:

Greetings,

Mario

 

[ChrisViperM]

Preparing the arms (Motors, LED's)


The Kratos features a unique connection systems for the arms which makes it simple to "un-plug" the arms for transport reasons. Each arm is equipped with the contacts for the motors and for LED's:

All cables are pre-installed and inserted inside the arm. Simply take the black plug out and you have access to the wires:

[

I removed all stickers from the motors (like on the first one in the pic) to reduce motor unbalance:

Next step is to feed the motor wires through the matching holes in the plug and solder them to the arm wires. It doesn't matter in which order you solder the wires since the running direction (CW or CCW) will be set later in the ESC's configuration software:

Once that was finished, I started with mounting the LED's. Finally I decided to put 12V LED strips (blue on the 2 front booms and red on the 2 rear booms). For most LED applications the LED wires from the arms would be long enough, but for what I had in mind I had to extend the a bit. Since the LED wires are crossing the motor-mount, I was afraid that the bare cables will eventually get damaged, so I covered them with a small piece of braided sleeve. Since the LED strips are just flat straight and the booms are rounded, I pre-shaped the LED strips a bit, but this has to be done carefully....I broke a few resistors on the strip and had to re.solder them.

Mission accomplished.....Arms are ready for use.

Next update coming soon........



Chris

 

[holco]

Actually it does matter Chris

If on every arm you solder the motor wires so that each wire has a fixed position corresponding with the plug's, like bleu is left / white is middle and red is right, and you solder also all the ESC's consequent
left wire to left plug / middle wire to middle plug and right wire to right plug, then you can put every CW arm on every CW place and vise versa, also it will be easier with programing the motor direction, example all even arm numbers will be CW and uneven CCW.

Mario

Preparing the arms (Motors, LED's)
Next step is to feed the motor wires through the matching holes in the plug and solder them to the arm wires. It doesn't matter in which order you solder the wires since the running direction (CW or CCW) will be set later in the ESC's configuration software:

Chris

 

[ChrisViperM]

Actually it does matter Chris

If on every arm you solder the motor wires so that each wire has a fixed position corresponding with the plug's, like bleu is left / white is middle and red is right, and you solder also all the ESC's consequent
left wire to left plug / middle wire to middle plug and right wire to right plug, then you can put every CW arm on every CW place and vise versa, also it will be easier with programing the motor direction, example all even arm numbers will be CW and uneven CCW.

Mario

Ok, so I cleared that one up with Mario.....He is absolutely right if you mark each arm as either CW or CCW, then of course they would be interchangable. In my case I have 2x arms with blue LED's and 2x arms with red LED's which have to go onto a matching connection on the frame, so there would only be 4 arms left for "interchanging" (in my case). I have each arm and each frame-connector marked with numbers, the only thing I have to do is to find the rotating direction of each motor and set it to the desired direction in the ESC software.

Need more time on programming the ESC's, but saved some time fiddling with a Multimeter to find the right cables for soldering......:tennis:


Chris

 

[SMP]

Those center plates make me salivate

 

[ChrisViperM]

Hey....where have you been lately......somehow missed you :tennis:


All the pictures can't do justice to the real thing.....everything is so precise and well thought. I will complete the build thread over the next few days.....next chapter is ESC's and canter plates.

Keep well....



Chris

 

[ChrisViperM]

Centerplates (Main Frame), Power Distribution and ESC's


The great thing about the Kratos is the fact that you don't really need a build manual. Everything comes assembled, you just have to take a few screws out, do your work and put the screws back. How many times did I build something, just to find out that there are some parts left/missing where I didn't know what to do with it.....not with the Kratos.

The most work on the Kratos is the Power Distribution Board (PDB)....everything else is easy.

With the Kratos comes a simple (but effective) PDB which consits basically of two copper rings and plastic stand-offs.....

once you build up your center with the Kratos PDB, it will look like this:

This method is very clean and easy to do since you only solder the power wires from the ESC's to the PDB and the motor wires of the frame to the ESC's.


Since I have some Gryphon PDB's laying arround: http://www.kopterworx.com/PowerBoards-/-Esc/Power-dist-board-8-+-Dual-Bec, I decided to use one instead of the original Kratos PDB. The Gryphon fits like a glove into the Kratos - just needed slightly longer stand-offs at the bottom than the original ones. I just underestimated the time it takes until it's finished.....hours and hours went into it, but I am more than happy with the result.

First you need to tke off the whole top-section (just a few screws) and the bottom section, including the mount for the spring wire dampening....that gives enough room for the soldering madness.

Once everything is dismateled, it will look like this:

It might be a good idea to bundle the cables coming from each arm, otherwise you see just an ocean of cables.....


Here is a "dry-fit" of the Gryphon bottom plate: (fits perfectly....thanks Mario :tennis: )

Next step is strip the ESC's:

After that, cutting some power and ESC cables (longer than needed) and soldering them to the Gryphon boards: (I de-soldered the Gryphon Bullet connectors)

Trying to find out if the whole cable mess can be mounted without any problems :

After test-fit was successful, the ESC power cables get soldered to the Gryphon:

Now comes the hardest part....implanting the whole mess into the frame:

Once it was done, it doesn't look that freaky anymore:

 

[ChrisViperM]

Now it's time to solder the motor-wires from the frame to the ESC's :

After is't finished, it looks like that:

Once everything soldered, the next step was to heat-shrink the ESC's again....but don't forget to put the extension cable from this ESC's (programming port) and route them to the front of the ESC. The heat-shrink gets cut out along the MOS-Fet's to provide direct contact to the heat sink. I used a thin layer of thermal paste between the MOS-Fet's and the heat sink for better thermal contact. Last step was to cover the ESC's signal cables with some braided sleeve. :

Next update comming soon......if you have any comments or questions, please feel free to post them


Chris

 

[SMP]

GREAT Post, love all the pics! Ended up looking quite tidy there, was worried for a moment mate

Got a chuckle out of the braided sleeve... we have buckets and buckets of the stuff. Cristiani has a slight cant let anybody ever see an exposed wire problem... I call it OCD, she calls it a polished and professional imagae supporting the brand... How the hell am I gonna win that argument!?! She wins and I do mean buckets... Good to be back, down on a gig in Brazil for a couple of weeks and some Miami follow ups. Had to go to work, no messing bout on the forums all day ;0

At any rate, looked like the Gryphon worked out well. Have been back and worth about whether I should use one for the Foldable I've got coming or just solder up a harness. Like how it worked out in yours!

 

[xerofly]

Excellent piece of work Chris.....very neat....

 

[xerofly]

GREAT Post, love all the pics! Ended up looking quite tidy there, was worried for a moment mate

Got a chuckle out of the braided sleeve... we have buckets and buckets of the stuff. Cristiani has a slight cant let anybody ever see an exposed wire problem... I call it OCD, she calls it a polished and professional imagae supporting the brand... How the hell am I gonna win that argument!?! She wins and I do mean buckets... Good to be back, down on a gig in Brazil for a couple of weeks and some Miami follow ups. Had to go to work, no messing bout on the forums all day ;0

At any rate, looked like the Gryphon worked out well. Have been back and worth about whether I should use one for the Foldable I've got coming or just solder up a harness. Like how it worked out in yours!

SMP...Good to see you...

 

[ChrisViperM]

GREAT Post, love all the pics! Ended up looking quite tidy there, was worried for a moment mate

Got a chuckle out of the braided sleeve... we have buckets and buckets of the stuff. Cristiani has a slight cant let anybody ever see an exposed wire problem... I call it OCD, she calls it a polished and professional imagae supporting the brand... How the hell am I gonna win that argument!?! She wins and I do mean buckets... Good to be back, down on a gig in Brazil for a couple of weeks and some Miami follow ups. Had to go to work, no messing bout on the forums all day ;0

At any rate, looked like the Gryphon worked out well. Have been back and worth about whether I should use one for the Foldable I've got coming or just solder up a harness. Like how it worked out in yours!

Brazil....that's where you have been.....I already thought you went to retirement because of filthy rich-ness. :tennis:
Cristiani is absolutely right.....dangling wires don't look pro.....in my case at least the copter looks pro, so I got moore room to be messy.
The Greyphon board is not cheap, but millions of options to solder those damn wires. Best part is the little BEC board...got a couple of 12V terminals and a few terminals where you can set the voltage between 5,6V and 8,4V....can get them for hexa and octo copters.

Once you find some time, let me hear about Brazil.....love this country, but don't understand a damn word....as long as my lady understands, it's ok with me. We almost moved to Brazil - Florianopolis, but now it will be Cape Town in mid of September....


Chris

 

[ChrisViperM]

Excellent piece of work Chris.....very neat....

Thanks a lot.....:tennis:

 

[SMP]

Chuckling here, Cape Town isn't gonna hurt your feelings my friend

 

[ChrisViperM]

It's about time to finish the buil-thread....have been busy lately.


Next step was to attach the ESC's to the ESC-plate, attach the top main plate and implant the YS-X6 and the receiver......basically some "reverse engineering..."

 

[holco]

Nice build Chris, love the red colored YS-X6!!

Mario

 

[ChrisViperM]

The actual build is finished now, all what is left is attaching the booms, some LiPo's and good nerves for the maiden flight. This won't happen before the next couple of weeks, since the Kratos will go straight into my container, heading South Africa.

As a conclusion I can say that the Kratos is one hell of a bird....during the build I did not have to rework one little thing, everything just fitted perfectly. Nothing awkward, just simly take a few things apart, fit components in and assemble....can't get easier than that.

How many hours did I already waste with hunting bits and pieces (on other builds) and trying to figure out what goes where, reworking not aligning holes, getting upset with screws or whatever missing......forget all that with the Kratos.

Another great bonus with the Kratos is the customer care....if I had any questions, I sent an email to Mario and always had an answer, the longest a few hours later, mostly within 1-2 hours.....try that with any other copter company on the market.



Here some impressions how it looks like when it's dark:

Chris

 

[ChrisViperM]

Nice build Chris, love the red colored YS-X6!!

Mario

Thank you.....had a hard time to find a Lexan spray paint matching the Kratos, but it was worth it.

Paint is: TAMIYA PS15 Metallic Red http://www.tamiya.com/english/products/list/polycarbonate_spray/kit86001.htm

Any other paint than the PS-series will come off !!!!


Chris

 

[RyanMcCrae]

what props will you run on it?