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Old Jun 04, 2011, 05:38 AM
Keith
Australia, New South Wales, Newcastle
Joined Apr 2011
337 Posts
No the failsafe on the rx was not set to max throttle only 1/3. Maybe the ESC is faulty, I did not notice the increase in motor speed whilst viewing the video until you pointed this out. The speed contoller is connected directly to the RX so unlikely this was caused by the FY21, only two points of failure the motor or the ESC. Maybe the failsafe on the RX was playing silly buggers going max throttle, anyone seen this before?

I concurr that the cause of the wing failure was probably full throttle dive with the FY21 trying to level up as it was in RTL mode.

Next issue to address is the lack of range with the Chainlink system after I build up a new wing. I am reading others experiencing lack of range with their Chainlink system as well. I purchased the 1/2 wave antenna to try and gain range. Looks like I am in


Quote:
Originally Posted by Daemon View Post
It appears the failsafe was set for full throttle, and when it lost the control signal
it went into a very steep dive at full throttle (pulling 60 Amps, so it was likely going
*very* fast), followed by what looks like hard up elevator when the signal was recovered
momentarily. No real surprise the wing snapped. VNE exceeded.
Same thing would happen with an EZ*, or EZG.. etc.

ian
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Old Jun 04, 2011, 06:12 AM
Outta Sight
Australia, WA, Joondalup
Joined Jul 2008
928 Posts
Keith,
your current is spiking to >60A just prior to a loss of control, and the attitude doesnt change at all.
Earlier in the vid you were looping at only 45A, was that full throttle on that loop at around 00:17
(Pity your OSD doesnt show speed)
Then your current goes massively high again and yet your plane just starts to drift into a nose dive.
On the way down (@ 7:16) I see the current at 77.7A and the (assuming 4S) pack voltage at 13.3v, this level would be a dead short on the battery.
Were you by any chance using a hobbyking motor? (They lose magnets and lockup, but you get what you pay for, believe me I've been there)
There must be a reason your current went to maximum and i would suggest a motor lockup, (possibly ESC too).
If I were you I would test run the motor and speedy and see what you get at max throttle.
I suspect you would NOT get figures that high if the motor was actually turning a prop.
Locked motor is my guess.
I dont necessarily think the wings broke on a pull-out, I'm thinking more of them coming off in the spiral late on the way down
I'd like to know what you find.
Roland
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Last edited by RolandS888; Jun 04, 2011 at 06:22 AM.
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Old Jun 04, 2011, 07:14 AM
Keith
Australia, New South Wales, Newcastle
Joined Apr 2011
337 Posts
Roland,
Yes the OSD does shows speed, left side in the middle. Agree that would not normally see amp drain that high. You are correct the motor is an Aero Turnigy with Turnigy 60amp ESC. I have yet to test the motor after the crash to see if it is servicable but turning it over by hand I cannot feel any crunching of magnets.
I will probably get some time tomorrow to do a run of the motor and ESC to see if they work correctly.
Thanks for you input, greatly appreciated as this crash is still confusing me. Not sure which occurred first the broken wing or the OSD going nuts.
cheers

Quote:
Originally Posted by RolandS888 View Post
Keith,
your current is spiking to >60A just prior to a loss of control, and the attitude doesnt change at all.
Earlier in the vid you were looping at only 45A, was that full throttle on that loop at around 00:17
(Pity your OSD doesnt show speed)
Then your current goes massively high again and yet your plane just starts to drift into a nose dive.
On the way down (@ 7:16) I see the current at 77.7A and the (assuming 4S) pack voltage at 13.3v, this level would be a dead short on the battery.
Were you by any chance using a hobbyking motor? (They lose magnets and lockup, but you get what you pay for, believe me I've been there)
There must be a reason your current went to maximum and i would suggest a motor lockup, (possibly ESC too).
If I were you I would test run the motor and speedy and see what you get at max throttle.
I suspect you would NOT get figures that high if the motor was actually turning a prop.
Locked motor is my guess.
I dont necessarily think the wings broke on a pull-out, I'm thinking more of them coming off in the spiral late on the way down
I'd like to know what you find.
Roland
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Old Jun 04, 2011, 08:33 AM
KJ6RCJ
gent96's Avatar
United States, CA, Elk Grove
Joined May 2010
406 Posts
Motor for SW

Guys,

Just got a Skywalker and before I start building it, I would like to get a general consensus of what the majority is using for a motor and battery sizes. I have read through 400+ pages of the thread and it's still confusing. I will be using the SW for Aerial Photography and video using the Gopro and the Ardupilot Mega for stabilization and autonomous flying; no FPV yet.

Through the thread, I found out that many use the 3536 and 3530 sized motors coupled with 5000mah 3S and 4S batteries. So for my application and for the general application of the SW, which power system is optimum? TIA

Gent
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Old Jun 04, 2011, 09:54 AM
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jsxx's Avatar
Wielka Brytania, Anglia, Derbyshire
Joined Jan 2011
416 Posts
motor

hi all
just bought skywalker and now im lookin gfor a motor, esc and battery.
1. lipo must be 3s
2.flight time more than 20min
3. easy climbing for high alt flights.

what do you think about 2814, 60amp esc, prop 9x6 and 5000mah 3s lipo ?
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Old Jun 04, 2011, 11:02 AM
Whats the wrst that can happn?
AdamChicago's Avatar
Chicago, IL USA
Joined May 2010
2,651 Posts
A Scorpion 3014 on a 4S with a 60amp ESC is an awesome combo!

Don't go cheap on the motor or ESC...you'll regret it at some point.
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Old Jun 04, 2011, 11:09 AM
KJ6RCJ
gent96's Avatar
United States, CA, Elk Grove
Joined May 2010
406 Posts
Quote:
Originally Posted by AdamChicago View Post
A Scorpion 3014 on a 4S with a 60amp ESC is an awesome combo!

Don't go cheap on the motor or ESC...you'll regret it at some point.
Expensive motor. Any other choice other than Scorpion?
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Old Jun 04, 2011, 11:39 AM
Outta Sight
Australia, WA, Joondalup
Joined Jul 2008
928 Posts
Quote:
Originally Posted by basadia View Post
Roland,
Yes the OSD does shows speed, left side in the middle. Agree that would not normally see amp drain that high. You are correct the motor is an Aero Turnigy with Turnigy 60amp ESC.
Yep, sorry, I missed the speed there on the left.
The high currents and no speed increase still suggest to me that the motor has a problem, especially as is it a Turnigy.
I have lost several motors exactly this way and now spend the extra on a decent motor.
I learnt the hard way its just not worth trying to save $50 on a motor when it can cost you a plane loaded with expensive stuff.
Be careful testing it.
Cheers,
Roland.
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Old Jun 04, 2011, 11:56 AM
AMA #535918
USA, NV, Las Vegas
Joined Apr 2006
321 Posts
Quote:
Originally Posted by AdamChicago View Post
A Scorpion 3014 on a 4S with a 60amp ESC is an awesome combo!

Don't go cheap on the motor or ESC...you'll regret it at some point.

What about an efficient motor for 3 cells? It seems to me the 3014 is made for 4 cells and therefore bigger/heavier than necessary for 3 cells.

I have lots of 3 cell lipos and would like to use them. I have zero 4 cells. But if over all efficiency is better at 4 cells, I'd consider it. But if 4 cells are more efficient than 3, what about a small 6 cell motor?
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Old Jun 04, 2011, 12:20 PM
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Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
28,219 Posts
Quote:
Originally Posted by RolandS888 View Post
Yep, sorry, I missed the speed there on the left.
The high currents and no speed increase still suggest to me that the motor has a problem, especially as is it a Turnigy.
I have lost several motors exactly this way and now spend the extra on a decent motor.
I learnt the hard way its just not worth trying to save $50 on a motor when it can cost you a plane loaded with expensive stuff.
Be careful testing it.
Cheers,
Roland.
The OSD stopped registering speed or altitude or distance or heading quite a while before
it freaked out. It was freezing up quite a lot and should not have been trusted
for RTL. Only thing the OSD was still showing in realtime was the current draw. Can
tell from the sound that the motor did not lock up. It was definitely at full throttle
and accelerating, and any motor/prop combo drawing 60amps on a Skywalker is going
to push it faster than it wants to go. The ESC controls the pulse width of the
current to the motor so even if the motor failed it shouldn't cause a current spike that
big. I've never ever seen an ESC "fail to full throttle".

ian
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Last edited by Daemon; Jun 04, 2011 at 12:27 PM.
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Old Jun 04, 2011, 12:26 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
28,219 Posts
Quote:
Originally Posted by vegasbs View Post
What about an efficient motor for 3 cells? It seems to me the 3014 is made for 4 cells and therefore bigger/heavier than necessary for 3 cells.

I have lots of 3 cell lipos and would like to use them. I have zero 4 cells. But if over all efficiency is better at 4 cells, I'd consider it. But if 4 cells are more efficient than 3, what about a small 6 cell motor?
Most folks who run a 3 cell pack also run a larger prop and thus require a raised motor mount.
I run a Scorpion 3008-1220Kv on 3S with a 10x6 prop which puts it pretty close to the
motor's current rating.
A 3014-1220kv gives you more than enough current margin, but it weighs more too (no
more than any other 1200ish kv motor out there though).

ian
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Old Jun 04, 2011, 12:37 PM
Registered User
Back in Hong Kong
Joined Sep 2003
963 Posts
I run a 4S setup on a Scorpion 30 SII (830kv I think) 3 blade 9x6. The power is great and will tick along on only a few amps. I have been running a 3800mah batt but I have just picked up a 4S 10000mah batt. Dont know if its a good idea yet. Time will tell.
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Old Jun 04, 2011, 01:20 PM
Praying for better weather
Coyote64's Avatar
Joined Dec 2007
4,103 Posts
On my new Skywalker, im running a JP EnErG C35-14 1550kv with a 9x4.5 41.3 amps, 1290g thrust, 390 watts 12,600 rpm

After seeing my mates Skywalker on the same combo i love it
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Old Jun 04, 2011, 01:22 PM
KJ6BFN
henkvdw's Avatar
United States, CA, Fountain Valley
Joined Aug 2008
718 Posts
Quote:
Originally Posted by gent96 View Post
Guys,

Just got a Skywalker and before I start building it, I would like to get a general consensus of what the majority is using for a motor and battery sizes. I have read through 400+ pages of the thread and it's still confusing. I will be using the SW for Aerial Photography and video using the Gopro and the Ardupilot Mega for stabilization and autonomous flying; no FPV yet.

Through the thread, I found out that many use the 3536 and 3530 sized motors coupled with 5000mah 3S and 4S batteries. So for my application and for the general application of the SW, which power system is optimum? TIA

Gent
My personal preference would be for a 4S set-up and a 3530(3008/2808) motor to suit with a 10 inch prop.
Two main reasons for 4S:
- The higher voltage (14.8V fully charged to ~12V fully discharged) and resulting lower current with lower associated losses.
- For 12V onboard equipment when stepping voltage down from 14.8V/12V to 12V, one needs only a step down. On 3S at full charge (12.6V) one needs to step down and then when discharged to 12V or lower, one needs to step up.

The 3536(3014/2814) size motors are hugely popular and a very good choice too. It gives a little more margin in thrust capability and heat handling - obviously dependent very much on your choice of kV and supply voltage.

Your pack capacity (mAh size) will depend on the endurance you would want for your missions and also maybe limited by the weight of all your AP gear. Although SW has demonstrated its ability to carry 2x 3S 5000 mAh packs.

On 3S I like Daemon's set-up.
The Scorpion 3008 x 1220kV with the 10x5E or 10x7E prop.
I'll be using this since I have two of these motors and two FlightMax 3S 4400 mAh 15C LiPo packs.

On 4S
Scorpion 3008 x 1090kV with 9x4.5E or 9x6E prop
or alternatively
Scorpion 3014 x 1220kV with 9x4.5E or 9x6E prop.
The latter will produce gob loads of thrust and the other advantage is that you could also run it on 3S if you so choose.

One word of caution, it appears that many of the failed wings we have observed so-far was somehow related to a motor over-thrusting and the plane going into a dive or spiral. This makes me think, I'd want to be very careful not to overpower my SkyWalker.
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Last edited by henkvdw; Jun 04, 2011 at 01:45 PM.
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Old Jun 04, 2011, 01:35 PM
KJ6BFN
henkvdw's Avatar
United States, CA, Fountain Valley
Joined Aug 2008
718 Posts
Broken Wing

Quote:
Originally Posted by basadia View Post
I have now seen the result of a broken wing in flight.......

Finally found my plane mostly in tact with a broken wing. I suspected as much from the video footage.......

Here are the pictures of the broken wing, as you can see the outer carbon fiber spar broke causing the crash:
basadia

Seems as though your SW is the V3? Please confirm.
Did you do any of the CF strip reinforcements as detailed by others in this thread? Does not look like there were any additional bracing installed except for the V3 center/outer CF tube?
Any tape on the wings?
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