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Old Dec 26, 2011, 12:32 PM
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Originally Posted by carguy1994ca View Post
How is the t-nuts wood beam held in the wing saddle ? just glued or is there some dowels going deeper in the foam ?
i just glued the nuts in the foam and the pvc. i took activator and instant adhesive. the nut is selflocking (dont know the word). for safty i take two strips like in orginalpackage were included. why did i glue nuts and skrews? because i want to fly in windy areal.

alex
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Old Dec 26, 2011, 01:09 PM
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ashdec87's Avatar
United States, MI, Detroit
Joined Feb 2004
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Quote:
Originally Posted by magicfox View Post
i just glued the nuts in the foam and the pvc. i took activator and instant adhesive. the nut is selflocking (dont know the word). for safty i take two strips like in orginalpackage were included. why did i glue nuts and skrews? because i want to fly in windy areal.

alex
He's asking because those plates might pull right off the foam with enough force. You might wanna drill a couple holes and glue in some pegs going down into the foam.
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Old Dec 26, 2011, 02:16 PM
NDw
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Ireland, Limerick, Kilmallock
Joined Aug 2010
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So V5 has two spars( one a bit shorter than the other), but only one hole for a spar. Anyone know what the second is for?

Thanks.
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Old Dec 26, 2011, 02:47 PM
Foam Snow
South Africa, WC, Cape Town
Joined Aug 2011
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I had a fantastic UAV flight this morning, 6.7km no problems. Even had 2 hawks join the SW at some point!

I;m just a little disappointed about range. I have 2 x 5000mAh 3S batteries and managed 6.5k dropping the batteries by 0.4V (24 minutes), which I calculate will give me ~ 30kms maximum range. I've seen people do much more with smaller packs, but maybe that's with some thermal activity.

Would it help if I use 4S in stead of 3S? Should I drop the KV? Should I reduce cruise speed?

I've used ecalc, but I can't really make out what to change to improve flight time See ecalc stats here. According to it, if I change my 1040KV Scorpion to a 830KV, I get almost double the flight time. I don't understand how this is possible and I'm doubting the result.

Any suggestions are greatly appreciated.
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Old Dec 26, 2011, 03:00 PM
Crash=start of next project
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United States, CA, Los Angeles
Joined Nov 2010
687 Posts
Quote:
Originally Posted by heinduplessis View Post
I had a fantastic UAV flight this morning, 6.7km no problems. Even had 2 hawks join the SW at some point!

I;m just a little disappointed about range. I have 2 x 5000mAh 3S batteries and managed 6.5k dropping the batteries by 0.4V (24 minutes), which I calculate will give me ~ 30kms maximum range. I've seen people do much more with smaller packs, but maybe that's with some thermal activity.

Would it help if I use 4S in stead of 3S? Should I drop the KV? Should I reduce cruise speed?

I've used ecalc, but I can't really make out what to change to improve flight time See ecalc stats here. According to it, if I change my 1040KV Scorpion to a 830KV, I get almost double the flight time. I don't understand how this is possible and I'm doubting the result.

Any suggestions are greatly appreciated.
I noticed if you change to a 9 x 4.5 prop you get more flight time. Have you tried that pitch? Very often ideal prop is Pitch = 1/2 Diameter. Example 9 x 4.5, 10 x 5. Also, are you sure the batteries are good quality and have not been abused to the point of not holding a good charge?
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Old Dec 26, 2011, 03:36 PM
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Saint Petersburg FL
Joined Jun 2009
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Quote:
Originally Posted by NDw View Post
So V5 has two spars( one a bit shorter than the other), but only one hole for a spar. Anyone know what the second is for?

Thanks.
fuselage tail
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Old Dec 26, 2011, 04:18 PM
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Australia, NSW
Joined Apr 2004
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Quote:
Originally Posted by magicfox View Post
i just glued the nuts in the foam and the pvc. i took activator and instant adhesive. the nut is selflocking (dont know the word). for safty i take two strips like in orginalpackage were included. why did i glue nuts and skrews? because i want to fly in windy areal.

alex
Add some rubber bands........I doubt that those nuts will hold.
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Old Dec 26, 2011, 04:21 PM
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Quebec, Canada
Joined Sep 2006
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Quote:
Originally Posted by muduck View Post
Add some rubber bands........I doubt that those nuts will hold.
Yea, its like the nuts could rip the foam off and you'd loose the wing
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Old Dec 26, 2011, 07:28 PM
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Las Vegas, NV
Joined Sep 2003
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Quote:
Originally Posted by heinduplessis View Post
I had a fantastic UAV flight this morning, 6.7km no problems. Even had 2 hawks join the SW at some point!

I;m just a little disappointed about range. I have 2 x 5000mAh 3S batteries and managed 6.5k dropping the batteries by 0.4V (24 minutes), which I calculate will give me ~ 30kms maximum range. I've seen people do much more with smaller packs, but maybe that's with some thermal activity.

Would it help if I use 4S in stead of 3S? Should I drop the KV? Should I reduce cruise speed?

I've used ecalc, but I can't really make out what to change to improve flight time See ecalc stats here. According to it, if I change my 1040KV Scorpion to a 830KV, I get almost double the flight time. I don't understand how this is possible and I'm doubting the result.

Any suggestions are greatly appreciated.
I'd been flying my SW on 3S 5000mAh packs with a 1290kv motor and 9x4.5 prop. Max amps was ~32A and I could get around 30 minutes +/- of flight time. Today I flew with a 980kv motor, 9x6 prop, and 4S 4300mAh pack (one 2100 and one 2200 in parallel). My OSD current sensor stopped working so I couldn't tell the inflight launch or cruising amps, but could still monitor the pack voltage. I landed at 30 minutes and when I recharged I put 33xxmAh back into the 4300mAh pack...so lower capacity battery, and same flight time with PLENTY to spare. I think I'll be upgrading to 2650 4S packs and should easily get 45+ minutes of flight. The SW even felt a little peppier in the air. I'm pleased with the 4S performance.
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Old Dec 26, 2011, 07:35 PM
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Lakewood, Colorado
Joined Aug 2002
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Quote:
Originally Posted by heinduplessis View Post
I had a fantastic UAV flight this morning, 6.7km no problems. Even had 2 hawks join the SW at some point!

I;m just a little disappointed about range. I have 2 x 5000mAh 3S batteries and managed 6.5k dropping the batteries by 0.4V (24 minutes), which I calculate will give me ~ 30kms maximum range. I've seen people do much more with smaller packs, but maybe that's with some thermal activity.
Judging range by voltage drop is error prone at best.
You need to measure the amount of juice you're putting back into your packs.
I did 20km in the air on a single 3S 4000mAh pack, putting 3300mAh back into it
on charge. That was level flight, *slow and steady*. Averaged 6.5A draw
over 30 minutes, at about 26mph. Unless you've wildly over or under propped
your plane, there's no reason to expect less performance than that. My SW
is pretty draggy with the GoPro out front, and flight camera perched on P&T up
top. With minimal aerodynamic improvements, should be able to cruise at 5A.
The main problem is going to be one of patience. People often just don't
have the patience to fly slow and efficiently, and a little throttle will easily
double your current draw, but it doesn't double your speed.

ian
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Old Dec 26, 2011, 07:39 PM
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Lakewood, Colorado
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Quote:
Originally Posted by Vantasstic View Post
I landed at 30 minutes and when I recharged I put 33xxmAh back into the 4300mAh pack...so lower capacity battery, and same flight time with PLENTY to spare. I think I'll be upgrading to 2650 4S packs and should easily get 45+ minutes of flight. The SW even felt a little peppier in the air. I'm pleased with the 4S performance.
Careful with the math here. Remember a 4S 4000mAh pack actually has 33% higher
capacity than a 3S 4000mAh pack, because it has one extra cell. Your min sink
cruise current draw will be 25% lower but instantaneous wattage, and total Watt hours
will be the same. There's some variation due to prop selection, motor efficiency etc,
but whenever you're comparing a 3S to a 4S setup, remember the 4S battery
is really 33% bigger.

ian
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Old Dec 26, 2011, 07:46 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
Las Vegas, NV
Joined Sep 2003
18,207 Posts
Quote:
Originally Posted by Daemon View Post
Careful with the math here. Remember a 4S 4000mAh pack actually has 33% higher
capacity than a 3S 4000mAh pack, because it has one extra cell. Your min sink
cruise current draw will be 25% lower but instantaneous wattage, and total Watt hours
will be the same. There's some variation due to prop selection, motor efficiency etc,
but whenever you're comparing a 3S to a 4S setup, remember the 4S battery
is really 33% bigger.

ian
Thanks. I'm really gauging by what went back into them I landed after 30 minutes with about 25% capacity to spare...so a good safety margin. If my current sensor was working I could of judged the cruising amps. On the 3S setup I normally flew ~24mph between 6A-8A. I noticed I was cruising around 30+mph on this flight. Dropping the speed down more would lower the amps and provide more flying time. I was a little nose heavy (balanced at the servo lead channel) so a better balancing job should help too. In all, I'm pleased and will certainly be flying 4S with it from now on.
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Old Dec 26, 2011, 07:55 PM
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Lakewood, Colorado
Joined Aug 2002
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My point is, cruising amps and the mAh you put in on charge, are both skewed
when using a 4S pack. You can't use amperage as your measure of capacity alone.
If total efficiency were exactly the same, a plane that cruises at 6A on 3S pack, will
cruise at 4.5A on 4S pack. And likewise, if after a min sink level flight you
re-charged a 3S 5000mAh pack with 4000mAh, you'd only put 3000mAh into a
4S 5000mAh pack. There's no gain in efficiency simply by going to 4S, you're
just adding capacity by adding another cell. Could get the same increase to the
3S setup by using a pack that's 33% larger.

There's nothing wrong with 4S, just be careful in thinking that you're
seeing a gain in efficiency, when really all you're seeing is a gain in battery capacity.

ian
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Old Dec 26, 2011, 07:56 PM
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Joined Jul 2011
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Quote:
Originally Posted by carguy1994ca View Post
Yea, its like the nuts could rip the foam off and you'd loose the wing
yes, thats right, i was sitting half an hour and hypnotizing the wings if they feel stiff enough...they said yes. i cut the foam about 6mm and glued pvc-plate in the foam with activator... i glued very deep also the nuts and glued another time some hours later and then used sandpaper.......
at least ,i dont know 100% if i can thrust my constuction and want to take the four gum-strips(dont know the word)
i made some better pics....i think that should work.
if its not rainy here i will make the maiden fly and try do make a video.

so far.
alex
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Old Dec 26, 2011, 09:20 PM
AMA #535918
USA, NV, Las Vegas
Joined Apr 2006
321 Posts
Quote:
Originally Posted by heinduplessis View Post
I had a fantastic UAV flight this morning, 6.7km no problems. Even had 2 hawks join the SW at some point!

I;m just a little disappointed about range. I have 2 x 5000mAh 3S batteries and managed 6.5k dropping the batteries by 0.4V (24 minutes), which I calculate will give me ~ 30kms maximum range. I've seen people do much more with smaller packs, but maybe that's with some thermal activity.

Would it help if I use 4S in stead of 3S? Should I drop the KV? Should I reduce cruise speed?

I've used ecalc, but I can't really make out what to change to improve flight time See ecalc stats here. According to it, if I change my 1040KV Scorpion to a 830KV, I get almost double the flight time. I don't understand how this is possible and I'm doubting the result.

Any suggestions are greatly appreciated.
Look at this chart. http://www.rcdude.com/servlet/the-te...1040Chart/Page

Your 3014-104 with a 9x6 is to small to get good performance from the motor (less than 50% power). Its only pulling 19 amps from a motor capable of pulling 40 amps. The 9x6 produces 1084 grams of thrust with an impressive 5.42 grams of thrust per watt of power consumed.

If you stuck a 10x5 on there you'd get 200 grams more of thrust with only 3 more amps giving and even better 5.6 grams of thrust per watt.

If you used a 4 cell and a 9x6, you'd have gobs more thrust available, but the thrust per watt decreases.

If you used a 3 cell and a 9x4.5, you'd lose even more potential thrust than you have now, but it the most efficient prop for that motor with more than 6 grams of thrust per watt. Scorpioncalc agrees that the 9x4.5 is most efficient with that motor on 3 cells. But a 10x5 is almost as efficient with lots more power available.
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