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Old Aug 28, 2006, 12:07 AM
WOOOOsssSSSShhHH !!
sparrow1717's Avatar
Long Island , NY
Joined May 2003
1,007 Posts
Just got done testing the lil J250 in a GWS "C" gearing (5.33.1) with a 9x7SF on a 1200mah 2 cell lipo. It has a lil over 10oz of thust at 5.3amps. With a 10x4.7SF it gets 12.8 oz at about 7 amps. My 21inch UFO AUW is 7.4oz with the 9x7. I should be able to "hang" the UFO this time.This is the first time messing with the J250 in a gearbox. Glad I bought a brick of em awhile back. Im quite impressed with it in a gearbox.

Maybe the next 21incher ill leave the "skin" on and throw a cdrom moto on it.

Spar
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Old Aug 28, 2006, 06:27 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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Prof , allthough the program says draggy , it sure doesn't fly like it ... My 21" with a 12t24awg cd motor and 2s 1200 is pretty fast , goes Vertical , and can easily harrier /hover...and it has a really nice glide .... just dumb Luck I guess ...

Upon GeneBonds recommendations , we've been flying a GWS /j250 (DCM-189) for years now with much success...10x4 0n C , 12x6 on D.. 2 cells only please...
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Old Aug 29, 2006, 12:14 AM
Got shenpa?
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Los Angeles
Joined May 2004
10,940 Posts
GPW, perhaps I misunderstood - I thought we were talking about direct-drive J-250 setups, which are good for small, fast planes, not big draggy ones.

I don't mean to be throwing any sand at your UFO, as far as I know dragginess comes with flat plate and low aspect ratio. Your 21" UFO zips about because it has so much power for the weight, we've all been spoiled with our lipo batteries and powerful motors!

I read recently that a Swift (that quick and agile little bird) only has about 3 watts per lb of body weight with which to maintain steady flight - now THAT's an airframe with very little drag! I haven't yet seen a flat-plate foamy that would come anywhere close to flying with only 3 watts per pound of weight to power it. Heck, we use more power than that per OUNCE!

Two years ago I used a J-250 in a gearbox on a 6-cell NiMH pack to wake up a flying buddies Yardstik. It would not even take off with the stock motor, the J-250 had it zooming through the air in no time. Great little motor!

That said, I think the BP-21 outclasses the J-250 - it handles at least twice the amps, and from a 3S pack, too. So if the BP-21 wouldn't fly the 48" Mother Ship, I doubt a J-250 would.

-Flieslikeabeagle
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Old Aug 29, 2006, 04:54 AM
Happy2ndChildhood
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London Ontario
Joined Aug 2005
1,361 Posts
Quote:
Originally Posted by flieslikeabeagl
So if the BP-21 wouldn't fly the 48" Mother Ship
-Flieslikeabeagle
Lets not forget the prop was on backwards when attempts made with the Bp21, a week or two ago I tried a skyblast prop on the j250 with Jerbear's simple wing with same results, gentle glide to the ground and was unflyable. Cut the spinner off the skyblast prop and flipped it over on the j250 and it is the best prop I have used on the j250 yet. I am sure the only prob with the Bp21 was my lack of attention to prop orientation. Will retry the Bp21 before I retire the monster ufo, but sure it will work.
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Old Aug 29, 2006, 05:57 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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It seems like there's something about these that defies conventional wisdom... TOG built his with an ips motor for cruising, and we've flown the UP in the past with ips motors and they were rather spritely, even with the heavier nimh ...

I'm not pushing any magic /mojo/voodoo airframe here , just making an observation , and anyone else who has made one of these (according to the plan ) would experience similar flying qualities ... It's just a really simple aircraft for Fun in the park ...and I've flown a 15t26awg/12t24awg cd motors on mine ... I make no claim for any of the many variations that seem to occur on this Forum , only what I've seen ...

and there's a really HUGE difference between the creator of the Swift and your humble narrator....

and in defense of the geared j250, it did fly my rather LARGE PPPPPorky Piper nicely ...
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Last edited by gpw; Aug 31, 2006 at 06:16 AM.
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Old Aug 29, 2006, 11:34 AM
Got shenpa?
flieslikeabeagle's Avatar
Los Angeles
Joined May 2004
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Quote:
Originally Posted by gpw
there's a really HUGE difference between the creator of the Swift and your humble narrator....
Yeah, you make nicer guitars, and not as many wars are started in your name!

-Flieslikeabeagle
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Old Aug 30, 2006, 07:24 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
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I just can't imagine how to respond that ....???? hahahahahahahahahahaha
If it was Up to me , Peace would be achieved by economic manipulation ....Not blowing the holy outta' everything , and only making the "chosen" arms manufacturers richer than they already are... nor accomplishing anything for 99.5% of the planets population .... cept killing alot of them off on both sides .... Just Totally' DUMB... and we're supposed to be so enlightened....I hate to say it , but I believe the electorate is as Dumb as the idea....

I know I'm gonna get some mail .....
Whoa!!! .... between me suggesting that we "Eat the Rich " and exposing the SS UAV program (saucers)... I know Uncle's boys will be visiting ....
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Old Aug 30, 2006, 12:00 PM
Sippin' on Kool Aid
Long Island NY, USA
Joined Dec 2005
2,807 Posts
just an update!

i maidened my hacker power geared inrunner UFO yesterday running a 12x6 SF e-flite prop and a 3s 1200 lipo. the thing flew great, insane power, vertical at half power and insane speeds at full power. i did a low fly by at full power and it seemed like it was going faster than anything i've ever seen!!

there was only one problem, i noticed a poop-load of flex in the wing when i was looping and just going general screwing around. it definetly needs some reinforcement. also, i figured out that if your diving down under power you neeed to turn the power off to pull up. (yea, i plowed it into the floor)
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Old Aug 30, 2006, 01:03 PM
WOOOOsssSSSShhHH !!
sparrow1717's Avatar
Long Island , NY
Joined May 2003
1,007 Posts
Heligrom -

More power ! * insert Tim Allen grunt here
thats got to be sick power !! Thats almost the power I use for a heavy aerial photography SS I have.

Good to hear . Its been pissin rain the last couple days here , glad you found a break. Today looks good though.

Im gonna try the geared J250 UFO hopefully today sometime.

Im gathering my components for a 36'' UFO ! I figure if i lit up with a mass of LEDs and take into altitude , it may pass for a "sighting" .

Hopefully the Men in Black wont knock on my door after they visit gpw.

Spar
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Old Aug 30, 2006, 02:08 PM
Foam Wannabe
Joined Nov 2005
578 Posts
Quote:
Originally Posted by gpw
Whoa!!! .... between me suggesting that we "Eat the Rich " and exposing the SS UAV program (saucers)... I know Uncle's boys will be visiting ....
Keep an eye out for those silent black helicopters and the guys quick roping down!
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Old Aug 30, 2006, 02:22 PM
Sippin' on Kool Aid
Long Island NY, USA
Joined Dec 2005
2,807 Posts
thanks sparrow. this disc was powerful, flew nicely to. it was so zippy but the sides flexed like crazy
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Old Aug 30, 2006, 05:06 PM
WOOOOsssSSSShhHH !!
sparrow1717's Avatar
Long Island , NY
Joined May 2003
1,007 Posts
ok- Just flew the geared J250 UFO !! Flies way better with a larger prop. I was able hover and turn constant inner and outer loops. I could make loops as small or as big as I wanted. I could make it "chase" its tail in a tight @ss loop. fun stuff

Hovering was good....but a lack of rudder made it harder to maintain.
Floats forever. I like blasting up to altiitude and cutting throttle and just gliding silently across the sky. Looks UFO'ish while doing so.

I must have got close to 20-30 mins of flight time with an old etec 1200 2 cell.
Pack and motor barely warm.

The geared J250 rocks !! Im thinkin of some cheap twin setups with these.

Spar
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Old Aug 30, 2006, 05:53 PM
Sippin' on Kool Aid
Long Island NY, USA
Joined Dec 2005
2,807 Posts
where can i get one of these J250's?? they seem to be really great.
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Old Aug 30, 2006, 06:07 PM
WOOOOsssSSSShhHH !!
sparrow1717's Avatar
Long Island , NY
Joined May 2003
1,007 Posts
I bought a brick of em ( 20 pcs) in the summer of 04' from Allelectronics.com . They do not have them anymore There are other versions of the johnson around (DCM189 , G404?). I beleive BPhobbies has some for $2.50. I bought my johnsons when they were 50 cents apiece !! You can see why they were lil gems for that price. With the insurgence of the DIY CDrom kits and cheap outrunners , they are not the cheap powerplant bargains they use to be.

Ive finally had the time to fart with them in different configurations and I am happy.

Spar
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Old Aug 30, 2006, 06:40 PM
Sippin' on Kool Aid
Long Island NY, USA
Joined Dec 2005
2,807 Posts
sparrow, would you by chance have anymore? i'd take one or two from you
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