Skyjib 8 Heavy Lifter Build

S

silastyler

Member
After pouring over the forum I realize this is probably a topic that has been covered to death. But I am building my first heavy lifter Octo and I'd love a little feedback as to my choice of components (Im also building a small quad to learn a little more about how these guys fly, based on the ARM 2.0 Flight Controller--I'm an Arduino geek). I realize every build is unique to one's circumstances, but if anyone sees something out of sorts with my list of gear, please chime in! These are components that I have already received or ordered, so I'm really just looking for a knee-jerk reaction from folks in case I've made an error in judgement going into my first build:

Skyjib 8 Frame with Retractable Landing Gear
Axi 4120/20 Motors
Castle Phoenix ICE 75 Amp ESCs
Hoverfly PRO, GIMBAL, GPS
Maxamps 5s 11,000mAh Lipos x2
Spektrum DX8 RX/TX with AR8000 and Telemetry Module
Xoar 14x5, and Xoar 15x8 Props (complete set each)
Cinestar 3-Axis Gimbal

Will be beginning to build in mid August, parts are all coming in. I'm terrified. I know I will probably spend thousands more just getting her to work right, but can anyone point to a glaring error in my list of assembled components?

Cheers, and happy flying!

Silas Tyler
 

T

tstrike

pendejo grande
How much will a beast like that cost, and yeah, yeah, "if you have to ask you can't afford it" (I can't afford it). I would think you'll need more than a dx8 unless that's the second op's tx. More batteries would probably be helpful, I'd burn through the first one just gettin the balls to push the throttle over 20%. Why not just go with the cinestar landing gear on the 360 mount or does it not attach to the skyjib frame? Have you done this sort of thing before?
best of luck and sorry I asked more questions then answers.
tom




oh and welcome to the forum.
 

Benjamin Rowland

Benjamin Rowland

Member
Looks like you've done your homework. That's a great setup - I assume you ran the numbers on eCalc for your intended payloads?

You'll definitely be happy with those components.

The only thing I'd suggest would be to consider going with the Futaba 8fg super. It's a great remote. But plenty of folks are happy with Spektrum.

Kopterworx has successfully attached a Cinestar gimbal to a Skyjib, so you may want to contact them about the details.

Good luck with your build!
-Benjamin Rowland
 

JLO

JLO

Member
Hi could you elaborate more on your plan for the Castle phoenix ICE 75 ESCs do you know of someone successfully on those motors
anyone?
 


J

jes1111

Active Member
Nice shopping list :)

Wiring will be critical on a big bird like this - at full throttle you'll be pulling around 300amps through the system. What's your plan for wire/connectors?
 

S

silastyler

Member
Thanks tstrike, the components came in at just under $9K. I plan to add more batteries once everything is working on the bench and she's had her first hover 3" off the ground :) My only rationale for going with the photohigher retract over the cinestar legs is the ability to remove them from the field of view of the camera..well, that and being able to get the camera that much closer to the deck if needed. I'm building this rig with the Red Epic in mind, and even though I don't trust eCalc to be 100% accurate, both those calculations and my own seem to point to the list of components I've assembled.

Thanks for the advice!
 

S

silastyler

Member
Thanks Benjamin, I will definitely contact Kopterworx about how they attached the Cinestar. I was assuming I'd have to fab up a bracket in the shop out of aluminum. I don't have experience with the Futaba 8fg, but I will look into it. I only have the one Spektrum so far, and will obviously need a second RX/TX for the other operator. Thanks for the advice!
 

S

silastyler

Member
JLO:

I contacted Castle Phoenix directly and this is what they said about the ICE controllers: "Silas, I am brand new to Multi rotor platform. I have a simple flame wheel to get me going. We have a support forum on RC Groups and there are many endusers there sharing their experiences which seem to be positive. From what I have personally seen the Castle Firmware is working very well... and I have the ICE 50's on my Quad... we are also running them on a Hex. I wish I had more info."

I also talked to Al at Hoverfly about his builds (He has been extremely helpful throughout my research process, and has helped me rule out several key components), and he suggested the ICE 50s or ICE 75s, which they use over there in some of there builds. He cautioned that the ESCs need to be running the latest firmware though, 4.01 I believe.
 

S

silastyler

Member
jes1111:

I completely agree. The 5s 11,000mAh I'm looking at will have 10AWG tails, and I plan to maintain that gauge straight to the wire bundle (soldered together) of leads from the ESCs.

So, 10AWG (30Amps x 120V = 3600W / 18.5V = 194 Amps from each battery before the wiring begins to breakdown)
194 Amps x 2 Batteries = 390 Amps / 8 ESCs = 48 Amps per motor. The AXi 4120/20 site maintains that the max current they can handle is 52 amps, so with this configuration the motors should never be starved for current.

The only break point (Bullet Connector I think) will be at the end of the battery tails. I'm planning to soldering the motor connections to the ESCs tails directly so there are absolutely no possibilities for connectors loosening. If a motor fails (and they will at some point I'm sure), I imagine the associated damage to the craft will require bench time anyway, so why not just make them all permanent connections right?



Thanks for your reply!
 
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JLO

JLO

Member
Thanks Silastyler what would be nice is to have other users of the Ice 50 and ICE 75 or other Castle ESC share their actual experiences on this elusive and some times complicated topic of ESC's on heave lift's would be nice now if a knowable rep from Castle Creations could post some data results proven recommendations on their ESC's for multirotors use, would even be nicer.
any one from Castle Creations out there ?
 

J

jrlederer

Member
I am finding this thread of particular interest considering I have nearly identical build sitting within view of where I'm sitting and writing this post!! This has been a project that I've put on hold for some time, since the drama surfaced regarding the Aerodrive 8 board that I originally slated or use on this monster. Since then, I made the leap of faith to go out and purchase 8 Ice 75s, but again I am hesitant to continue due to the uncertainty of how to proceed with the power distribution aspect. The last thing I need is to invest all the time getting them is talked and then having the wiring loom overheat and come apart midair. That would definitely put a negative spin on my day!! Please keep this thread up-to-date with what you end up deciding on so far as the PDB is concerned, as that is what is stopping me from going ahead with the completion of this long-overdue project.

By the way, I splurged for the Kopterworx adaptor that makes for clean interfacing of the SkyJib frame and Cinestar 360° gimbal. It is very clean looking and very good quality, so far as I can tell without having actually flown with it yet. Looks leigit though and saved me the hassle of attempting to create my own solution. The one thing you absolutely will need is the retract extensions that are also available on Kopterworx website, due to the Cinestar adaptor assembly lowering the gimbal an inch or so from where you might expect it would attach. They are easy to pop on and lift the bird enough or the gimbal to have proper clearance when on the deck.

Good luck with your build. Seems like a great component list to me, as I chose the same stuff. Now to see how it fairs. Please, please keep us posted on the progress and hopefully fantastic results!!

--Jonathan
 

S

silastyler

Member
Thanks Jonathan, I will make sure to keep this thread as up to date as I can as I begin my build. It's really good to know I'm not the only one that has these components and am stressed out about the PDB. When I talked to Al at Hoverfly I thought I had made up my mind about going with an Aerodrive board, even with the one case that seems to keep popping up on the forums about one that completely failed in the back of my mind. Al told me he had clients in Europe reporting Skyjib frames with the Aerodrive board were "dropping out of the sky." I'm not sure if it was just a couple bad apples, or if that is a systemic problem for these heavy lifters, but it was enough to scare me away from them for good.

I may end up going to a lower gauge for the loom, in between batteries and the ESC leads (#8, or #6 AWG) just for a little overhead in terms of capacity.

Thanks so much for the info regarding the Kopterworx adapter for the 360 gimbal, I had no idea one existed. Very glad to hear I don't have to fab one myself.

I will post pix of the wiring setup in late August once everything is on the bench.

Thanks so much for the advice.
 

R

R_Lefebvre

Arducopter Developer
Silastyler, glad to see you're going with Arducopter. ;)

I just ordered a bunch of parts to build my own Octo. But on a much lower budget. Turnigy NTM 3536-900 motors, F-40A ESC's, and I'll be semi-scratch-building my frame from miscellaneous parts from Hobby King. Mostly the machined Alu motor mounts, CF tube, and I'll make a custom hub. I looked at all the frames on the market, and I just wasn't happy with what I'd be getting for the money.
 

J

jes1111

Active Member
I wouldn't touch an Aerodrive for a Red-carrier, personally. Not only are you placing all your eggs in one basket but you're also placing that basket in exactly the wrong place - dead centre in the frame, hidden beneath everything else where it will get little or no airflow. I don't advocate that ESCs should always go on the arms under the props but, when in doubt, it's a damn good place for them. I've seen so many statements from people like "the spec says my ESCs are okay up to 85ºC and mine are only at 84ºC" - the truth, of course, being that heat kills anything electrical/electronic so you should always keep temperatures (of everything) as low as possible, especially when your passenger is a Red camera!

Good idea on the soldered wiring, although you should never need to go thicker on a wire than what's already provided - i.e. if the batt has 10AWG then there's little/no advantage in using 8AWG between it and the next junction point. Same with the ESCs - match the gauge of the fly-leads they come with and you'll be good. Don't forget that 300A of DC will produce some wicked EMI so twist the pos/neg pairs together right the way through the system.

One neat trick I learned for making soldered junctions is to use small lengths of thin brass tubing. Squash it into an oval in a vice and you have a perfect receptacle to poke the (pre-tinned) wires in from both sides then fill with solder. You need a big-*** soldering iron, of course. The other trick is to use individual strands of copper (pulled from a length of multistrand) to "bind" the pre-tinned ends together so they're held while you solder them all together.

For connectors I just can't bring myself to trust hobby-grade stuff - I've gone with Anderson connectors - crimped ('cos that's actually better than soldering). They make 'em in all sizes and the ratings are meaningful (and actually very conservative). So they're bulky, sure, but peace of mind is more valuable than some otherwise unoccupied space. I've actually gone with multiple 5000mAh packs just to spread the total draw across more connectors (I'm using the "45Amp" Anderson's).
 

K

koolkiwikat

Member
silastyler said:
After pouring over the forum I realize this is probably a topic that has been covered to death. But I am building my first heavy lifter Octo and I'd love a little feedback as to my choice of components (Im also building a small quad to learn a little more about how these guys fly, based on the ARM 2.0 Flight Controller--I'm an Arduino geek). I realize every build is unique to one's circumstances, but if anyone sees something out of sorts with my list of gear, please chime in! These are components that I have already received or ordered, so I'm really just looking for a knee-jerk reaction from folks in case I've made an error in judgement going into my first build:

Skyjib 8 Frame with Retractable Landing Gear
Axi 4120/20 Motors
Castle Phoenix ICE 75 Amp ESCs
Hoverfly PRO, GIMBAL, GPS
Maxamps 5s 11,000mAh Lipos x2
Spektrum DX8 RX/TX with AR8000 and Telemetry Module
Xoar 14x5, and Xoar 15x8 Props (complete set each)
Cinestar 3-Axis Gimbal

Will be beginning to build in mid August, parts are all coming in. I'm terrified. I know I will probably spend thousands more just getting her to work right, but can anyone point to a glaring error in my list of assembled components?

Cheers, and happy flying!

Silas Tyler
Click to expand...

Why are you over building so heavy its a tank your way over powered!, your motors are 320grams each! 2.4kgs on motors alone, your ESC's cost a fortune and are heavy, build around what your lifting not the other way around, many have made the mistake(me included, bigger/heavier is not better) and over engineer there builds

Scrap the motors and go for these instead, weight is your enemy as you will pull more current thru the system, you will never pull max current unless you are doing punchouts....with a gimbal Im guessing your wanting to do some AP so less is more, trust me on this, less weight = better efficiency = more

http://www.himodel.com/electric/HL_...6-8_rotors_5-10kg_flight_weight_Aircraft.html

If you want to keep the setup you have re PDB, keep it simple, get yourself a small power dist block used in car audio(think copper bling used in car audio installs) and use bare wire, it will be bullet proof and will dance all night and day without breaking a sweat!

Props(I use em)

http://www.himodel.com/plane/15x_5.5_Carbon_Propeller_Set_one_CW_one_CCW.html

Personally Id go with the YS-X6 as my FC, not a fan of Hpro, Zerouav and DJI FC's are the big players imho both have big budgets and many users!


Im building a 6kg max octo around something similar to what Jab has built(see his pics and video) here for around $1500 including electronics(APM2) and will haul anything I can throw at it
http://www.rcgroups.com/forums/showthread.php?t=1669877&page=4
Powered by these
8x
http://www.himodel.com/electric/HL_...otor_for_Quadcopter_Multi-rotor_Aircraft.html

Build it around efficiency(low watts per gram) thats your goal....it doesnt have to be a tank lifting crane!, dont get caught up in the hype and bling of carbon dreams...its overated

Master your smaller quad, build around what you want to lift, then the rest will happen!

Cheers!
 
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K

koolkiwikat

Member
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JZSlenker

JZSlenker

Yeah, I can blow that up.
Personally with that payload I'd go with an X-8 so you have some redundancy. It looks like you are over powered, but that's not always bad, especially with an epic.
You will LOVE the Hoverfly FC. This last firmware is just incredible. I just can't believe how smooth it is. The best part about Hoverfly besides being the best FC I've flown, is that you can talk to the engineers directly both here and on RC groups.
 

J

jes1111

Active Member
KoolKiwiKat is proposing some interesting components and this is a fundamental decision that every heavy-lifter must make: "lightweight sports car" with potential fragility or "over-powered tank" withbullet proof performance. Lotus vs Mercedes, if you like. With any electrical/electronic system, the closer you run to its rated capacity the higher your risk of failure will be. It's the same with mechanical systems - lighter equals more fragile. The gap between these two approaches can be closed (to some extent) with "money". So its one of those "pick any two" choices: lightweight, reliable, cheap.


Personally, to fly a RED, I'd go with the OP's approach - over-specify everything. Efficiency/flight times are much less important than reliability - long flight times are not needed, absolute reliability is.
 

Vortex

Vortex

Member
Hi Silas, I started building the same machine a while back also and it too has been shelved waiting for a more reliable Power Board. I was originally going with the Hercules boards with MK guidance but sent the boards back when I started hearing about machines falling out of the air after their boards burnt up. Andreas has been working on a higher current board which is getting very close to completion now.

The reason I wanted to go with the Hercs was the AXI 4120/20 motors are really only any good as a heavy lift motor when running on 6S. Run them on 5S and you're not going to get the full potential from them and you will be much better to look at different options which will be lighter and give you more rpm/lift (as already posted)

Please keep us up to date with your progress as I am sure there are quite a few of us interested to hear how you get on.

Regards,

Lance
 

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