USAF simple as it gets - Page 101 - RC Groups
Thread Tools
Jun 02, 2007, 06:56 AM
“There’s no place like Foam”
gpw's Avatar
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...
Sign up now
to remove ads between posts
Jun 02, 2007, 10:57 AM
AMA 42867
callmeishmael's Avatar
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.
Jun 02, 2007, 01:34 PM
feel no remorse
youth must fly's Avatar
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.
Jun 02, 2007, 01:53 PM
AMA 42867
callmeishmael's Avatar
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.
Jun 04, 2007, 08:17 AM
“There’s no place like Foam”
gpw's Avatar
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...
Jun 04, 2007, 08:40 AM
AMA 42867
callmeishmael's Avatar
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.
Jun 05, 2007, 07:44 PM
D'oh.. Dumb Left Thumb
dekan's Avatar
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"!
Jun 06, 2007, 02:12 AM
Registered User
sloper steve's Avatar
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!
Jun 06, 2007, 07:09 AM
“There’s no place like Foam”
gpw's Avatar
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 of all Steve speaks ENGLISH , not 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 ...
Jun 06, 2007, 11:15 AM
Too Little Too Late
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.

Jun 06, 2007, 12:37 PM
Flying...Pushing Air Down
sr71fan's Avatar


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:

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

Last edited by sr71fan; Jun 06, 2007 at 07:17 PM.
Jun 06, 2007, 01:11 PM
“There’s no place like Foam”
gpw's Avatar
Incredibly COOL !!!! Whoa!!!!! Totally Alien....
Jun 06, 2007, 01:12 PM
Krued Up
snolord1's Avatar
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 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

Jun 06, 2007, 06:14 PM
“There’s no place like Foam”
gpw's Avatar
Forget about it Dude... Merry Christmas!!!
Jun 06, 2007, 06:39 PM
AMA 42867
callmeishmael's Avatar
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!"

gpw will get this.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Rave As shabby as it gets........... John M Slope 3 Jan 07, 2005 10:38 AM
Is 3D flying as hard as it gets ? OzzieFlyer 3D Flying 21 Mar 21, 2004 10:46 AM
Almost, as good as it gets uglystick Parkflyers 5 Nov 24, 2003 05:14 PM
I am as new as it gets and need some insight. Skawrpion Sport Planes 19 Sep 23, 2003 07:28 PM
the p51 as real as it gets bassplay Scale Kit/Scratch Built 1 Mar 03, 2003 05:28 PM