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Old Jun 02, 2007, 05:56 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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My cardboard UFO DPF ended UP at 15 oz. That's the weight you flew it at ... recent mods have brought it down to 11... 4 whole oz. is alot of weight on this plane ... and as my feather weight EPP UFO proves, lighter is ALWAYS better...
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Old Jun 02, 2007, 09:57 AM
AMA 42867
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Joined Nov 2003
584 Posts
On reflection, the problem was not so much the weight as the CG. With everything installed right against the front edge the 30" was balancing at 35%. I velcroed on another 3S 800 LiPo at the field and that brought it to 30% - and the weight to something over 15oz - ouch. The result was that it just wallowed nose high at full throttle on launch. I was dumb enough to try to get on top of it and the third and last crash, from about eight feet AGL, was hard enough to dislodge one of the motor's magnets.

Rather than a smaller motor, I think a bigger one, along with a 1200 LiPo would have helped by putting the CG where it needed to be and improving the thrust/weight ratio. As it was, the motor had neither the thrust to pull the thing into straight flight nor was it pushing enough wind over the elevons to make them effective. Once I launched I was pretty much a spectator.

I flew the same setup on a 24" version that flew very well and balanced correctly. The 30" was, like the 24", directly scaled up from gpw's original.
No innovations.

A built up structure will be harder to repair however the trade-off is that it won't hit as hard.
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Old Jun 02, 2007, 12:34 PM
feel no remorse
youth must fly's Avatar
underground
Joined Jun 2004
1,184 Posts
Somehow i cant understand why was it such a challange for you to balance the 30" disk with that equipment. I mean i built my 37" version with the equipment that weight 10oz with those gws mini std servos. And the disk itself balanced at 27% It flew fine no tail heavy really.
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Old Jun 02, 2007, 12:53 PM
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I couldn't agree more. The 24" didn't require having all of the components shifted all of the way forward. Nonetheless, that's where it came out.
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Old Jun 04, 2007, 07:17 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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You guys are worrying too much ... Just think of it as a simple ratio .... when you make the dia. of the disk bigger, you have to use proportionately bigger materials (the reverse for downscaling)and bigger motors(more power)/ props/batteries /servos ,etc....don't worry , because as you get bigger so does the wing area...and the actual wing loading (oz/sq.ft) may actually go down , plus you're getting out of scale effect into "real" air ... all good ...Balance is still the same ...
Weights, you could even work it out exactly, mathematically ... simple ratios...
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Old Jun 04, 2007, 07:40 AM
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You're right, of course. My problem was that I was trying to balance more weight with the same gear. I have some 1550 3S LiPos on the way that should solve the problem nicely for this one.
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Old Jun 05, 2007, 06:44 PM
D'oh.. Dumb Left Thumb
dekan's Avatar
London, UK
Joined Nov 2006
5,398 Posts
I am trying to set up my Futaba 6exap TX for elevon mixing on my PI/UFO and have noticed this strange effect.
If I push the stick full travel diagonally one servo travels to 120% or there abouts the other remains centered. if I pull the stick from side to side or up and down the servo movement is normal. If I switch the rate switch on when stick is fully diagonal it makes no difference to the servo "throw".
The rates work normally with normal stick movements.
I have tried all elevon menu combinations.
Am I losing the plot or is this normal.... a bug in the programming?
I use elevon mixing on other planes and I have checked them and they all do the same thing.
I have never had problem when flying, but then I dont push the stick fully into the "corners"!
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Old Jun 06, 2007, 01:12 AM
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America the ruling country
Joined Dec 2003
3,204 Posts
JCL,
Concerning Sloflys motors:
It is $5 markup but not $5 profit.
The business does not make enough except for some meals and takes most of my time.
Something is wrong with our system that the consumer concludes this while the vendor is scraping by.

With a return the postage would cost more than the motor markup.
UH allows you send it in if you want it fixed which is exactly what happens if you order it from them.

Shipping from UH will be more money or take more time than ordering in the U.S.
Single motor orders go out priority mail right away.

The best reason to order the motors from Slofly is speed of delivery.
It is usually same day and $4.60

Oh the UFO!
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Old Jun 06, 2007, 06:09 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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Steve's right , a little mark Up like that doesn't go very far when you have "overhead"... those little expenses like rent, electricity, taxes... 5 bucks doesn't go very far ...best of all Steve speaks ENGLISH , not engrish...so he ALWAYS gets the order right , unlike our Chi cousins...and it allows Steve to continue making those wonderful EPP planes that he designs and manufactures. You can bet , I'll be doing business with him...


and about the UFO ... Just FUN , FFF or EPP .. we've built em' both ...
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Old Jun 06, 2007, 10:15 AM
Too Little Too Late
MICHIGAN... 48189
Joined Jan 2002
323 Posts
Holy cow--

Just saw a picture of the U F O that Germany came up with in WWII ; I was going to increase the distance between my elevons to 6" on the 30".
Have made that 13" and it looks good. Will let you know the results when I get time to finish it. Strange I never heard of that because I was a pilot in WWII, must have been Top Secret.

Jerry
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Old Jun 06, 2007, 11:37 AM
Flying...Pushing Air Down
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Clovis, NM, USA
Joined Nov 2000
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Back-Up

Well, my 2nd UFO type flies even better than the first. I guess 'cause it's a little bigger. This one is 22.5 inches in diameter. Motor is E-Sky's smallest, battery is 2S 730 DualSky. Hovers just above half throttle. Weighs just 7.3 ounces at liftoff. Videos here:

http://www.rcgroups.com/forums/showthread.php?t=696215

"But REALLY, officer... I didn't mean to SCARE anyone!"

Gary
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Old Jun 06, 2007, 12:11 PM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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Incredibly COOL !!!! Whoa!!!!! Totally Alien....
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Old Jun 06, 2007, 12:12 PM
Krued Up
snolord1's Avatar
United States, MA, Springfield
Joined Jul 2004
4,527 Posts
i tried PMing you Glenn.
good thing you contacted me,i was going to do so today because i still havn't gotten a cleared check copy so i'm thinking that either it was delivered to the wrong place or it got lost.is there a more faster way that i could send funds to you?if not just shoot me your addy again and i will cancel the check written previously and write you a new one and send it out today as i have to go to the post anyways.this type of is what me off about USPS.they lost a whole plane from Brian(punkindrublik)that he sent me,so i don't put it past em to have lost a lil white envelope.sorry for the delay...apologies

Angel
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Old Jun 06, 2007, 05:14 PM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
24,132 Posts
Forget about it Dude... Merry Christmas!!!
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Old Jun 06, 2007, 05:39 PM
AMA 42867
callmeishmael's Avatar
Joined Nov 2003
584 Posts
Quote:
Originally Posted by sr71fan
Well, my 2nd UFO type flies even better than the first. I guess 'cause it's a little bigger. This one is 22.5 inches in diameter. Motor is E-Sky's smallest, battery is 2S 730 DualSky. Hovers just above half throttle. Weighs just 7.3 ounces at liftoff.

"But REALLY, officer... I didn't mean to SCARE anyone!"

Gary
gpw will get this.
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