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Old Sep 16, 2012, 12:40 AM
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Daemon's Avatar
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Can't think of any forum that does that.
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Old Sep 16, 2012, 12:58 AM
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Antarctica
Joined Oct 2010
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Has anyone tried flying with 2 5000mah 4s ? Wonder if that would be too much
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Old Sep 16, 2012, 02:21 AM
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rcmonster99's Avatar
United Kingdom, England, Milton Keynes
Joined Sep 2003
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Quote:
Originally Posted by octane81 View Post
Has anyone tried flying with 2 5000mah 4s ? Wonder if that would be too much
I would say it is too much...there is a point where carrying too much weight becomes useless. you will need to reinforce the wing (make it even heavier) and you will waste most of the extra energy just carrying that weight about .

I am guessing the overall result but be the equivalent of carrying a 6000 4s

Maybe the 1900 version would be better for that because of the extra wingspan, but then again this wing will need extra reinforcing and it will be a slower plane.

this is only a guess. the only way to demonstrate it is by practical observations.
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Old Sep 16, 2012, 04:57 AM
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Australia, NSW, Picnic Point
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I used to fly with a turnigy 8000mah 4s with no dramas at all till I crashed into the ocean.

The SW handled the weight fine so long as I wasn't trying loops and rolls.
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Old Sep 16, 2012, 07:21 AM
Needs more cowbell...
Australia, QLD, Brisbane
Joined Jul 2011
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Im using 2 3s1p 5000mAh batteries. Only one is ever connected, the second one is in there to simulate my final weight with all my gear and for CG until I get confident enough to move cg. I wont have all my fpv gear on until i figure out a few quirks.
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Old Sep 16, 2012, 03:24 PM
Foam Snow
South Africa, WC, Cape Town
Joined Aug 2011
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Quote:
Originally Posted by rcmonster99 View Post
I would say it is too much...there is a point where carrying too much weight becomes useless. you will need to reinforce the wing (make it even heavier) and you will waste most of the extra energy just carrying that weight about .

I am guessing the overall result but be the equivalent of carrying a 6000 4s

Maybe the 1900 version would be better for that because of the extra wingspan, but then again this wing will need extra reinforcing and it will be a slower plane.

this is only a guess. the only way to demonstrate it is by practical observations.
I've been flying 2x5000mAh 4s for a year now on my 1900, I'm not sure exactly what the run time is - I've never had to come in to land because of low battery If anything it's very stable. CG is critical though - too far to the front will get you in trouble not able to pull out of a dive. The only reinforcement is tape along the length of the wing.

On the stock 1680 - I agree with rcmonster - it's beyond the point of diminished returns.
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Old Sep 16, 2012, 03:53 PM
Nakelp
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United States, NJ, Union
Joined Sep 2004
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Anyone looking for electronics, motor, prop etc. can look up this thread:
http://www.rcgroups.com/forums/showthread.php?t=1494373
any new set ups welcomed there too :-))
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Old Sep 16, 2012, 05:21 PM
If it's to be, it's up to me.
subsonic's Avatar
Sydney, Australia
Joined Jan 2007
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Quote:
Originally Posted by heinduplessis View Post
I've been flying 2x5000mAh 4s for a year now on my 1900, I'm not sure exactly what the run time is - I've never had to come in to land because of low battery If anything it's very stable. CG is critical though - too far to the front will get you in trouble not able to pull out of a dive. .
If CG is to far to the REAR it would be hard to pull out of a dive. Unless you have other things going on like flex in the stab / elevator.
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Old Sep 16, 2012, 05:57 PM
OSUFPV - KF7VFT
Corvallis, OR
Joined Apr 2010
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Quote:
Originally Posted by octane81 View Post
Has anyone tried flying with 2 5000mah 4s ? Wonder if that would be too much
Yeah, same as others above me, flew with 8Ah of 4S. Was no big deal for the
skywalker. Just make sure your wing and wing attachment is very solid or keep
the g-loading very low. My V4 wings had the 2 spars, two CF strips to the
wingtips, and 10 mil lam on the entire outer surface. Overkill? Yes. Piece of
mind? Yes. 7g yank and bank? Priceless.

-Blues
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Old Sep 16, 2012, 06:16 PM
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Winnipeg
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Please take my comments in the best of ways.
I was right where you are a few months ago.
I like to read so went through the whole thread and saw the same questions asked over and over, sometimes posts after the answer.
When it comes to the building of the plane, there are certain things you must do.
Glue the CF boom rod in solid. Make sure to run alll cables, and even tape things up so you can test out cg.
Wings, minimum good fiber tape underneath. Ribbon CF top and bottom if you want to really stiffen it up.
One I learned the hard way. Motor mount. I had my motor come off. I took the plate that came with the plane, drilled 4 holes that fit snug with 4 x 3/4" wooden dowels. I used wood glue and glued them into the disk. I then drilled 4 holes to match in the foam. That I glued into the mount. Then I epoxied another disk to the one I had mounted. It is this disk that I used the motors x mount so I could remove the motor when I needed to. It won't be falling out any time soon.
I did put in the 2 cf ribbons on the front sides of the vertical stab. From just under the horizontal stab to along the boom.
I don't trust the 4 elastics I got, and strange things happened to me using them. Since I have switched to 6 x #27 SIG elastics, no issues at all.
Also depends on how you fly. The most stress my skywalker see's is on take off.
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Old Sep 16, 2012, 08:26 PM
If it's to be, it's up to me.
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Sydney, Australia
Joined Jan 2007
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Elevator Reversal

Quote:
Originally Posted by subsonic View Post
If CG is to far to the REAR it would be hard to pull out of a dive. Unless you have other things going on like flex in the stab / elevator.
This actually brings me to a point that I have been going to make in this forum for a while, but held off till I did some more testing, and had time to write it up. I have a Skywalker 1680mm version 4, but this would translate to any of the other versions I would think, since the fuselages are all the same. Many have already pointed out that the whole Skywalker tail is pretty floppy if built standard. I have added some bracing between my horizontal stabiliser and the fin, since it adds a bit to the stiffness of the horizontal stabiliser, and secures it to the fin a bit better. Iíve flown my Skywalker this way for ages, and have always said in here that although the tail wobbles around a bit, it doesnít effect the performance in flight at all. Iíve always reasoned that itís an FPV plane, and if youíre looking at the tail in flight, youíre looking the wrong way! Iíve just changed my mind, and I actually think the floppy tail can bring you undone if youíre not careful and this is why:

The other day I was flying FPV in front of some friends. I was flying fast(ish) and low along the strip, through and around a line of trees at the end of the field and around several obstacles at low altitude. One of my friends commented that it looked to be going pretty fast, and since I have the ET OSD with airspeed module, I could say that I was doing about 61mph flat out, straight and level. Now, I donít trust this airspeed sensor as far as I could throw it, but this day was calm and the airspeed numbers were reading pretty close to the GPS speed, so I think it was near enough. As you do, I started showing off and getting a bit carried away. Iíve reinforced the wings on my V4 which has dual spars, with carbon ribbon top and bottom. My wing is very stiff and much stronger than stock, so I felt OK to push it. I headed into a low pass from about 300í up. I had the throttle wide open and as I was flying down towards the runway, I was indicating 74kn airspeed. As I went to pull up to level, I got no response out of the elevator! The ground was rushing up pretty quick so I pulled the throttle back to idle. Airspeed dropped away quickly and the elevator response came back. I skimmed the ground at no more than a couple of feet. It was a bit scary, but the good news was that it looked in control from the ground.

What I think is possible with the Skywalker at high speed, is that if enough load is placed on the elevator, you can get a control reversal. There is enough flexibility in the boom and the stabiliser itself so that when the elevator surface deflects up, it pushes down on the horizontal stabiliser and bends it to a point where it INCREASES the angle of attack of the stab. The elevator starts to act like a trim tab, with upward deflection of the control surface pushing the horizontal stab trailing edge down.

A few days after this and after a good look over, I tried it again, but at higher altitude. I was able to repeat it where I found that at about 70kn the elevator response becomes very mushy. Responsiveness always returned though when the power is reduced. I would think that this effect could be even worse with a forward CG position, because the horizontal stabiliser would be working hard in normal flight anyway to keep the nose up. Youíd be asking even more of it when the airspeed and G goes up. My CG is at 25mm behind the servo wire slots. I should probably move it back a little more.

Anyway I just thought Iíd share my experiences, and maybe encourage you to think about how you fly your Skywalker, or if you really want to push it, take steps during the build to stiffen the boom and stabiliser.
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Old Sep 16, 2012, 09:48 PM
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Are the Skywalker wings easily removable for transport? I worry that it won't fit in my car otherwise.
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Old Sep 16, 2012, 10:27 PM
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Australia, NSW, Picnic Point
Joined Aug 2011
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Quote:
Originally Posted by Zangetsu57 View Post
Are the Skywalker wings easily removable for transport? I worry that it won't fit in my car otherwise.
Yep very, so long as you dont fix them permanently and arent planning on flying it like a Yak or Mustang ect.

I have 2 extra carbon strips in each wing, and have the original carbon spar fixed into one wing so i can undo the aileron plugs, remove the fat arse rubber bands i use and transport it in its original box modified slightly with no dramas at all, just the tail is a bit of a fragile area so i just have to make sure the box is tied down lightly with nothing touching or able to fall on the tail plane.
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Old Sep 16, 2012, 10:28 PM
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Teamsherman's Avatar
Australia, NSW, Picnic Point
Joined Aug 2011
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Quote:
Originally Posted by subsonic View Post

Anyway I just thought Iíd share my experiences, and maybe encourage you to think about how you fly your Skywalker, or if you really want to push it, take steps during the build to stiffen the boom and stabiliser.
Hey dude, Ive done the same thing but with a 3mm fibre glass rod. A tip i got of PMRfly when i first built my SW.
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Old Sep 16, 2012, 11:36 PM
Flying Zayin
Cathay Stray's Avatar
China, Guangdong, Guangzhou
Joined May 2012
799 Posts
Thread about reinforcements and other structural modifications

I decided to follow Nakelp86 and start a new thread which could serve as a digest of mechanical modifications users make on their Skywalkers.

The thread SKYWALKER - airframe setup and structural reinforcements is for any NON-POWER and NON-ELECTRONICAL modifications, namely:

- Extra carbon/glass fiber reinforcements
- Optimization of internal space
- Landing gear
- Fixing the wings on the fuse
- Re-hinging of control surfaces
etc., etc., etc.

Please post your build logs there with reasoning and explanations.
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