What power plant combo for the Skyjib 8?

W

whirlwind

Member
Can anyone suggest the correct power plant combination for the Droidworx Skyjib 8 with the AV200 gimbal and camera? I will be using the AXI 4120/20 motors to power the Skyjib 8. According to E-calc using the 14x4.7 props with an all up weight of aprox 9kg and a 5 cell Lipo the unit will fly at sea level with a very high power setting of over 90%. This is not ideal. When flown at an elevation of 5000 ft the unit will not fly at all unless there is a substantial weight reduction. E-calc says it will fly using this combination with a 6 cell pack, but it would prefer I change the props to 15x5. Has anyone had actual flying experience with these combinations at various altitudes and in higher temperature climates?
1. Are such props as a 15x5 available, if so where can I get them?
2. When they talk about different props are they referring to Slow Fly props or are they talking about E Props?
Any help would be appreciated.
 

Vortex

Vortex

Member
Hey Graham, Looks like we are at the same crossroads waiting for the green light!!!

I have decided upon a 6S power supply for my SJ8 via Hercules II boards and MK guidance, Axi 4120/20 motors and Xoar 15 x 5 props. From what I have been able to ascertain so far the props are on the small side and that could be a good thing to start off with.

You can get the props here and the price is not too bad for a pair of them http://www.kopterworx.com/Xoar-props/Xoar-prop-15x5-pair

I would have liked a pair of Graupner 14 x 8 props but the PF is getting up there 112 compared to 75 with the Xoar props I have ordered. Anyhow time will tell and I might very well get a set of 15 x 6 to experiment with.

I haven't had a lot of input from fellow SJ8 owner/builders and I'm thinking there either are not a lot of these out there or they're holding their cards close to their chests and don't want to share their experiences......

Anyhow I have just ordered the parts to build my unit......How far along are you with yours??

Regards,

Lance
 

jackwrangham

jackwrangham

Member
Hi Guys

We have been flight testing an SJ8 over the weekend. Graupner 14x8 props, Axi 4120s and 2 x 5S 5500mah packs. Lifting 2.5Kg (AUW about 10kg). E-calc said we would need 90%ish power to lift - but it was lifting at 50% so im not sure eCalc is entirely accurate. Flight time was only about 4.5 mins down to 30% left in packs. We've also got Xoar 15x5s on the way and 5S 8000mah batteries, although I think we will try 6S as well.

Be good to keep each other in the loop to find the optimal set up.

Jack
 

DKTek

DKTek

Member
Hey guys

I'm still waiting for the AEROdrive8 to ship..... My SJ8 setup and plans:

(8)15-20 Plettys
APC 14" props until I hear some more feedback and hopefully someone will make a set of CF 14" and 15" props soon with the heavy lifters in mind. I wouldn't mind the price...too much.
AEROdrive 8
MK guidance
(2)AV-200/360Pros with 7.2v roll mods
(2)5s 35c 6500mah packs for now, will try other combos as well
Radios: Futaba 14MZ, 9ZHPS, JR 11X, and DX7's. All modded with long range RF modules.
Video Downlinks; 900, 1.3, 5.8, and 2.4 for directional hopping if needed... HEY, I'm a very long time FPV nut with all the gadgets.

Cameras owned include Canon 5D Mk2, 7D, 3D HeroV2, and a lot of FPV cams.

I have access to pretty much any camera that I want to try through professional vendors so I plan on making a few cam/lens configuration combo kits, i.e.- having known settings and positions for any type of weights or supports for proper gimbal balance and function. That's why I like having two gimbals that I can either swap out quickly or use the Droid 8HL.

My Ground stations are getting sorted as for FPV, I just use a table with the components spread out, nice and unorganized. Time to stuff it all into a couple of Pelican Cases, nice and neat for clients.

I do have the landing gear attached to the gimbals but I'll make a stand and remove the gear for weight eventually. However, the gear is a great place to attach the downlinks but they can be moved to the roll assembly too.
 

quadcopters

quadcopters

Quadcopters.co.uk Drone Specialists
jackwrangham said:
Hi Guys

We have been flight testing an SJ8 over the weekend. Graupner 14x8 props, Axi 4120s and 2 x 5S 5500mah packs. Lifting 2.5Kg (AUW about 10kg). E-calc said we would need 90%ish power to lift - but it was lifting at 50% so im not sure eCalc is entirely accurate. Flight time was only about 4.5 mins down to 30% left in packs. We've also got Xoar 15x5s on the way and 5S 8000mah batteries, although I think we will try 6S as well.

Be good to keep each other in the loop to find the optimal set up.

Jack
Click to expand...


What are you using for your Flight Controller Wkm or Mikrokopter Or Hoverfly ?

Geoff
 



quadcopters

quadcopters

Quadcopters.co.uk Drone Specialists
You will most likely find all WKM will lift at mid stick this applies for large and small but don't also take E-calc as gospel because I have found it is not always accurate .

Geoff
 

DKTek

DKTek

Member
seattle_helo said:
DKTek, you've been waiting for the power board for months now, correct?
Click to expand...

Yup, I was one of the first orders. Last word was that they were to ship between the 15 and end of January. No updates since that has passed.

Everything else has arrived.
 

jackwrangham

jackwrangham

Member
quadcopters said:
You will most likely find all WKM will lift at mid stick this applies for large and small but don't also take E-calc as gospel because I have found it is not always accurate .

Geoff
Click to expand...


WKM will calculate needed throttle and take of at 50% stick when in atti or GPS mode, but we also test in manual mode to see the actual throttle stick position, it was about 54% in this case (i think).

Cheers for the confirmation on eCalc, never trust computer simulations fully! still a great tool though. J
 

Droider

Droider

Drone Enthusiast
I have to say I read of so many people using ecalc for pre-trial testing and use information they gain from it for their builds.. thats kind of a short cut to experience in the building of MR craft.

From my experience there is only one way.. and thats chucking in more time than the wife / partner will tolerate, more money than a serious drug addition, and the perseverance to get what you need built flying and fit for YOUR purpose. Every ones expectations are different and with out the experience to talk things through with either supplier or client this is a real mine field.

Know exactly what you want. Ask the right questions and trust the guys who really know what they are doing.... I got to tell you there aint many of them about.. especially be wary of the new kids on the block who have come from other AP fields and think that can jump in to MR's like it is an easy transition from single rotors platforms.

I have spent THOUSANDS and THOUSANDS on trusting others who have had my trousers down because I did not know better but trusted their so called experience. ALWAYS ask to see examples of their work/ references from previous clients.. Any so called expert will have a client list that is more than willing to promote and endorse the services they have experienced.

In the life time of this forum we have seen so called experts come and go, heard the heartache of those left behind in the so called EXPERTS wake as the so called experts disappear in to cyber space.

READ THE FORUM..ask the members opinion of any supplier / service provider and most importantly DONT JUMP at the first offer that seems to fit your requirements.. trustme it WONT

Remember the the old saying.. 'ACCESS your flexible friend' well my aint flexible anymore because of this bloody addition!

Still love it when it comes together as planned!

Dave
 




Droider

Droider

Drone Enthusiast
EH up Ross u spent as much time as most of us in this as one of the fist members.. Thanks for the endorsement of my views.. I know you have been through the mill like I have but seeing your last pics makes me feel proud to be a contributor like yourself to this GREAT forum.. Especially since you come from a professional single rotor world.

Dave
 

Macsgrafs

Macsgrafs

Active Member
Droider said:
EH up Ross u spent as much time as most of us in this as one of the fist members.. Thanks for the endorsement of my views.. I know you have been through the mill like I have but seeing your last pics makes me feel proud to be a contributor like yourself to this GREAT forum.. Especially since you come from a professional single rotor world.

Dave
Click to expand...

Professional single rotor world, AKA... shake your camera gear to bits in pursuit of perfection ;) ;)
Thanks Dave, if it wasn't for people like yourself & the many others on this forum, I would still be chasing my tail with a trex 600esp heli!

Multi rotors are indeed an addiction, an emotional rollercoaster of successes & failures, that's worse than any decent smoke ;)

On this forum are the future pioneers, the ones who will show us the way to go & fight the addiction!

Ross
 
Last edited by a moderator:

W

whirlwind

Member
Thanks for all the replies, it is much appreciated.
After all the research I have done on the large heavy lift platforms I get the feeling that there is really not that much info out there on what really are the best combinations. This is possibly true due to the fact that the heavy lift platforms are still quite new and the folk are still experimenting.
In the following text I am referring specifically to propulsion and stability on Multi Rotors. I have realized that a power plant combination that somebody chooses to use may not necessarily work for somebody else. For instance somebody has set up their heavy lifter to fly at sea level. All works great! Then take that same combination and take it to 5000ft elevation above sea level. If the unit was marginal at sea level it will definitely struggle or more than likely not fly at all at higher elevations. This in turn will affect your PID / gain settings on your controller as the motors thrust characteristics have changed.
Density altitude is also a huge factor. A high temperature of say 30 deg celcius at 5000ft elevation will make the aircraft perform as if it were at 7800ft. This is very common where I live in South Africa. By the same token a heavy lifter flying in a crisp cold environment will have great performance and will therefore have fantastic stability due to available thrust.
I have noticed on most of the forums folk will go into great detail about their machine, providing lists of equipment used for their particular setup but will seldom make mention of their conditions or location. I believe it is crucial to make mention of your environment in order to help others.
Just my two cents worth!
Graham
 

DKTek

DKTek

Member
whirlwind said:

I have noticed on most of the forums folk will go into great detail about their machine, providing lists of equipment used for their particular setup but will seldom make mention of their conditions or location. I believe it is crucial to make mention of your environment in order to help others.
Just my two cents worth!
Graham
Click to expand...

I agree that the environment is crucial but but some folks don't have a clue where the next shoot may be. We should be able to adapt our systems for the occasion and client needs. After some well earned experiences, you'll have a sense of what may be needed for future shoots. Cold WX, hot WX, wet or dry, things will change for each,
 



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