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Old Aug 17, 2008, 06:56 PM
The Penultimate flyer
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Australia, WA, Cooloongup
Joined Apr 2007
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Excellent, thanks buddy.
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Old Aug 22, 2008, 07:49 AM
The Penultimate flyer
TSnake's Avatar
Australia, WA, Cooloongup
Joined Apr 2007
1,509 Posts
This is very frustrating,

I can't get this thing to balance out.

I want to use an Emax BL 2810/12 motor.
1100 KV, 38 A max, 11x6 prop, 1.4 kg of thrust......sounds perfect I thought.
Sure it weighs 86 grams, so it's not small, but others in this thread say they're using an AXI 2814/12 motor, which weighs 106 grams !!!!

How the do they do it ? How do they get it to balance with a 106 gram anchor sticking out back ?

One 2400 mah battery hanging off the nose doesn't even come close to balancing it.
Not even two 2400 mah batteries will do the job.
Do I go for three or four or five ?
Or do I just put a car battery on the nose ?

I'm using a CG machine, so I know exactly where the balance point is (about 3 feet behind the plane).

I don't want to add dead weight to the plane, because I really want it to glide and thermal.

Any help greatfully accepted.

THE END.

Edit : I just found this link to a Maxi build guide done by MS Composit
http://www.technoflight.no/shop/articles/MS-18000.pdf

In it, it shows them fitting two 2400 mah batteries in parallel....hmmm it doesn't say that in my instructions.
Still, I tried that already and it didn't work, so I still need help.
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Old Aug 22, 2008, 09:45 AM
Bleriot's R Us
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Ireland, Donegal
Joined Nov 2003
1,076 Posts
I have a 2217-6T (approx 75g) motor fitted at present plus a aluminium spinner nut and 8x4apc style prop
I have fitted two JR 591 servos. I have covered the whole bottom of the wing in bullet tape (strapping tape) I fly with either a 1800 3 cell long max or a chinese 2200
I have have approx 180g of lead in a slot in front of the battery hatch which is 90mm back from the nose (to middle of battery)
total weight ready to fly with 2200 pack is 1085g (2lb 6ozs)

I screw a cup hook into the plastic mount and hang it from the roof to check CG
Mine balances at 325mm back from the nose, these things will fly with a wide cg range I have flown it with no lead as it fell out after a bang and I never realised, needed a lot of down but still flew.
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Old Aug 22, 2008, 11:02 PM
The Penultimate flyer
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Australia, WA, Cooloongup
Joined Apr 2007
1,509 Posts
Thanks xairflyer,

You've been a great help,
Have you noticed that we currently seem to be the only people on this planet who have any interest in Swift Maxis ?
Looks like no matter what I do, mines going to be a bit on the "chubby" side.
Strange because I built it as light as I could (maybe we have more gravity down here).

I can balance it with three 2400 mah batteries...AUW 1.28 kg

Or

I can use lead sinkers and two 2400 mah batteries...AUW 1.23 kg

Or

I can use even more lead sinkers and one 2400 mah battery...AUW 1.18 kg

I'm not sure which way to go, I'll make a snap D and start cutting soon.
I'm tempted to sacrifice performance for extended flight times, and go with the three batteries and no dead weight.

EDIT : I've decided to go with a single battery - minimum weight, maximum glide.
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Old Aug 23, 2008, 06:06 AM
Bleriot's R Us
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Ireland, Donegal
Joined Nov 2003
1,076 Posts
You might be still trying to balance it too far forward, did you try my method and measurement ?

I have attached pic of the bottom of my wing the reciever is to the right of the yellow esc, lead is in front of the battery.

I also fitted covers over the servo arms to give them some protection
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Old Aug 23, 2008, 08:25 PM
The Penultimate flyer
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Australia, WA, Cooloongup
Joined Apr 2007
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Hanging it from a hook is a brilliant idea, could have saved some money if I'd thought of that...but then again, with my machine I can balance any plane without cutting into them to attach an anchor point.
And what do you do if you decide to change your CG ? You'd have to drill another hole wouldn't you ?
Mine's also balanced at 325mm from the nose.

I incorporated an idea that's been floating around in my head for some time.
I replaced some of the lead sinkers with a steel rod that I bent to conform to the shape of the nose, I then cut a shallow groove in the leading edge and hot glued it in place ( it hasn't/shouldn't upset the aerodynamics at all).
It looks good, and should offer some protection to the battery as I've had to put the battery so far forward to get the CG right.
Could also give it a secret weapon as a combat wing...it'll slice the others in half.

Sorry I can't show you any pictures of mine just yet, I'm still waiting on a camera that I ordered from ebay some time ago.

But here's a picture of the CG Machine that I use, it's made my life alot easier.
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Old Aug 24, 2008, 05:03 AM
Bleriot's R Us
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Ireland, Donegal
Joined Nov 2003
1,076 Posts
Yes it is only a tiny 2mm hole in the plastic not noticed, other benifit of this method is you can check if one wing is heavier than the other, which was the case on my swift 2
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Old Aug 24, 2008, 07:39 PM
The Penultimate flyer
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Australia, WA, Cooloongup
Joined Apr 2007
1,509 Posts
I got up before sunrise and maidened the Maxi this morning.

Conditions were perfect, warm, no wind, slightly overcast skies, and the field all to myself (actually I had half a dozen Kangaroos as an audience (..they really did seem interested)).
Because of its weight, I decided not to launch it like my Swift II (underhanded toss at half throttle then grab the controls and hope for the best). Instead I launched it with no power applied and a gentle over head push to keep it flat, this worked really well and I had plenty of time to take the controls.

The next bit's tricky to describe, because it left me....umm...speachless.
.................................................. ...............................................

Here I am 5 minutes later, with coffee in hand, trying to wipe the idiot grin off my face, and the words still aren't coming.
.................................................. ...............................................

OK I'm calm now:
The first push of the throttle proved I had more than enough power, as I later discovered, it will go straight up vertically, 'till it's just a tiny speck in the sky.
It needed a few clicks of down elevator to stop it nosing up under power, as does my Swift II, I may look at changing the thrust angle, or if it's even possible, do some clever throttle-elevator mixing in my DX7 transmitter.

As expected, everything happens slowly in the air, it's a heavy wing, and it carries alot of inertia. In my case, that's a good thing...I was after a cruisy, relaxing wing with some gliding abilities.

Did I say "SOME gliding abilities" ???

I cut the throttle, and the Maxi's real strength becomes blindingly obvious.
It glides like it's a special effect from a movie, and not a particularly believable movie either.
It just hangs there.

I fitted an onboard battery level indicator [a bank of red/yellow/green LEDs] into the belly, and after 15 minutes, I dragged it down for a low pass to check the LED status...all green...vertical climb for some more gliding.
The first flight lasted 27 minutes, and the LEDs still showed green.

The second flight lasted 34 minutes !!! and at the end of the flight it still showed all green LEDs.
I'll have to wait and see if the onboard indicator is "optimistic", I'll see how much current's needed to charge the batteries. But the throttle response didn't drop off, so I suspect the LEDs were telling the truth.

The third flight only lasted 8 minutes, I had a ball, doing tight loops and rolls, and screaming low passes {it actually wasn't very fast, but the engine noise combined with the sight of this BIG wing passing close by, is very impressive}.

There is just one thing I hate about the Maxi.....

It makes all the other planes I own, look like crap.

EDIT: I didn't make it as clear about the impressive flight times as I intended.
It was overcast, at sunrise, so the ground hadn't warmed up yet.
The point being, I didn't get any assistance from thermal activity, it was just falling back to earth at a ludicrously low rate.
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Old Aug 24, 2008, 07:55 PM
Bleriot's R Us
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Ireland, Donegal
Joined Nov 2003
1,076 Posts
How does it roll, I had to add some differential to get it to roll nice
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Old Aug 24, 2008, 08:15 PM
The Penultimate flyer
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Australia, WA, Cooloongup
Joined Apr 2007
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It doesn't roll quickly, and that doesn't surprise me.
It is "chubby", and although the control surfaces are big, they're also kind of "floppy".
[that's enough technical speak for now]

I was thinking of stiffening the ailerons somehow, and hoping the servos are up to the challenge.
Hmmm...add some differential you say, I never thought of that. I just assumed it was a design weakness, and not something I could "work around" with clever programming.
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Old Aug 24, 2008, 08:54 PM
Not your average DiggsyBear
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Raleigh, NC
Joined Dec 2006
8,859 Posts
Quote:
Originally Posted by Trouser Snake
I got up before sunrise and maidened the Maxi this morning.

Conditions were perfect, warm, no wind, slightly overcast skies, and the field all to myself (actually I had half a dozen Kangaroos as an audience (..they really did seem interested)).
Because of its weight, I decided not to launch it like my Swift II (underhanded toss at half throttle then grab the controls and hope for the best). Instead I launched it with no power applied and a gentle over head push to keep it flat, this worked really well and I had plenty of time to take the controls.

The next bit's tricky to describe, because it left me....umm...speachless.
.................................................. ...............................................

Here I am 5 minutes later, with coffee in hand, trying to wipe the idiot grin off my face, and the words still aren't coming.
.................................................. ...............................................

OK I'm calm now:
The first push of the throttle proved I had more than enough power, as I later discovered, it will go straight up vertically, 'till it's just a tiny speck in the sky.
It needed a few clicks of down elevator to stop it nosing up under power, as does my Swift II, I may look at changing the thrust angle, or if it's even possible, do some clever throttle-elevator mixing in my DX7 transmitter.

As expected, everything happens slowly in the air, it's a heavy wing, and it carries alot of inertia. In my case, that's a good thing...I was after a cruisy, relaxing wing with some gliding abilities.

Did I say "SOME gliding abilities" ???

I cut the throttle, and the Maxi's real strength becomes blindingly obvious.
It glides like it's a special effect from a movie, and not a particularly believable movie either.
It just hangs there.

I fitted an onboard battery level indicator [a bank of red/yellow/green LEDs] into the belly, and after 15 minutes, I dragged it down for a low pass to check the LED status...all green...vertical climb for some more gliding.
The first flight lasted 27 minutes, and the LEDs still showed green.

The second flight lasted 34 minutes !!! and at the end of the flight it still showed all green LEDs.
I'll have to wait and see if the onboard indicator is "optimistic", I'll see how much current's needed to charge the batteries. But the throttle response didn't drop off, so I suspect the LEDs were telling the truth.

The third flight only lasted 8 minutes, I had a ball, doing tight loops and rolls, and screaming low passes {it actually wasn't very fast, but the engine noise combined with the sight of this BIG wing passing close by, is very impressive}.

There is just one thing I hate about the Maxi.....

It makes all the other planes I own, look like crap.

EDIT: I didn't make it as clear about the impressive flight times as I intended.
It was overcast, at sunrise, so the ground hadn't warmed up yet.
The point being, I didn't get any assistance from thermal activity, it was just falling back to earth at a ludicrously low rate.
Evil!!!! I have been wanting to know if it was as floaty as the swift II and I think you just told me it might be even more so. I am going to have to get one of these. I love my Swift II but want something larger that I can take up high and just thermal around or float if there is no lift. The Swift II has really impressed me with it's ability to stay in the air forever on one lipo. I got over 45 minutes once on a 1000mah 3S Loong Max pack. I am using a hacker motor which is very efficient, but still, 45 minutes off a 1000mah is kind of nuts. I will read up and see if I can find your specs on your MS. Curious what gear and Lipo you are running.

Grrrr, yet another aircraft I must have!!

Thanks for the report and forgive me for cursing at you behind the monitor

Diggs
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Old Aug 24, 2008, 10:48 PM
ProBro # 501
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Austin Tx
Joined Jul 2005
1,861 Posts
Can motors be installed on the Swift II..?? and if so what size and do they have a USA link..? Thanks

Boss
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Old Aug 24, 2008, 11:32 PM
The Penultimate flyer
TSnake's Avatar
Australia, WA, Cooloongup
Joined Apr 2007
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Hi Boss248, this link should answer any questions, this is the Swift II that I've got [I like naked ladies- brilliant marketing, how did they know ?].

I also bought the Swift II Power SET with the AXI 2208/26 motor, it's perfect.

http://www.mscompositusa.com/swift-i...blue-wing.html

Hi Diggs, I'll list my setup, when I find my reading glasses [no I'm not that old]
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Old Aug 25, 2008, 12:22 AM
The Penultimate flyer
TSnake's Avatar
Australia, WA, Cooloongup
Joined Apr 2007
1,509 Posts
Found 'em, it's a mystery why they're always in the last place you look, why couldn't they be in the first place ?

Emax BL 2810/12 motor-1100 KV [EBAY $US 40.00]

APC 10x5 prop [I'd love to try an 11x5 or 6, but would have to trim the ailerons]

50 A ESC [EBAY $US 20.00]-turns out this is overkill, as I just measured a max current draw of only 23 A WOT on a bench test.

A single 2400 mah 15C Mystery LIPO [EBAY $US 22.00]

Spectrum AR7000 Rx

ON-BOARD BATTERY LEVEL INDICATOR [EBAY $US 18.00]

2x MG995 Metal Gear Digital Servos [EBAY $US 18.00 for 2]

Lots of lead weights in the nose [I think about 300 grams]

$US 40.00 worth of flourescent pink paint...worth every cent.

The list above probably represents the best money I've spent in this hobby up 'till now.
Can't wait 'till tomorrow morning, when I get to do it all again.
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Last edited by Trouser Snake; Aug 25, 2008 at 06:35 PM. Reason: Wrong prop size, changed 10x6 to 10x5
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Old Aug 25, 2008, 05:38 AM
Bleriot's R Us
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Ireland, Donegal
Joined Nov 2003
1,076 Posts
The glide of the maxi is much much better than the swift II

I did also put a bit of carbon strip along the edge of my ailerons to help stop them flexing.
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