F-9F Cougar - balsa (and a little foam) scratch build ***maiden video*** - Page 5 - RC Groups
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Dec 31, 2011, 06:26 PM
corsair nut's Avatar
sweet fuzz! join the club!

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Dec 31, 2011, 08:06 PM
Retired and Lovin' it!
TPfingston's Avatar
The little F-5 looks neat Fuzz. I'll be watching for it.

Dec 31, 2011, 09:01 PM
Boogie_'s Avatar
F-5 fever must be in the air.
One of my posse came by the shop Friday with some plans for a big F-5. I think he's doing twin 90's.

RoV tiger stripe camo would be cool Fuzz.

Dec 31, 2011, 09:05 PM
corsair nut's Avatar
or a 12ft t38......
Jan 01, 2012, 08:46 AM
Big gov never Works
St. Martin's Avatar
Yea, I have been following the bohemoth T-38. To fit (2) 70mm fans: the exaust is 18mm now, x 3=54mm(doable). That gives a 72" LOA and a 39" WS. Or,I could use two 66mm, in the same size. I have a set of Eflite retracts. But probably too small for our field. I will most likely keep it bungee launch and real lite. Then I could get away with two 525W systems with (2)5s 1800's and 4W motors. 27A each.

About 10 yrs ago, they must have had a F5 squadron in Mass. I was fishing on a pond in norther RI, when two flew overhead. I could barely see them. They were around 5 thousand, and blended perfectly. What sticks in my mind, was how smooth and strait they flew. Seconds later, two more flew over at half the altitude. I did not know they were there, until they passed. This was shortly after 9-11. And there were many such sights, in the following weeks. Mostly F-16's.

I found a treasure trove of old kits, at a hobby shop in Poughkeepsie NY. Jemco, Easy built, Todays Hobbies, Some Sterling. Low prices too.

Jan 01, 2012, 10:55 AM
corsair nut's Avatar
fuzz thats the exact same size as the twin 70 mm f5 i did! mine was 5.25 lbs with twin 450 w 70 mm setups...made from depron
Jan 01, 2012, 06:13 PM
Big gov never Works
St. Martin's Avatar
Hey Brent, I just remembered, I owe you an A-4 canopy. Sorry. I'll get it to you.

Yes..6' is a good size Jet. Probably the biggest since my IC days and Byrons.

Jan 01, 2012, 07:28 PM
deltas are cool
AIR SALLY's Avatar
sounds big but its just long and skinny
Jan 07, 2012, 09:47 PM
Boogie_'s Avatar
Making progress on the Coug.
All the glassing is done and I started cutting out the gear doors. I did learn one thing, I suck at cutting out gear doors.

They're gonna work fine but the gaps are much bigger than I was shooting for.
Inboard doors still need to be glued to the hinges.
Jan 08, 2012, 08:30 AM
Big gov never Works
St. Martin's Avatar
You'll do better next time, Julian. It's like anything else..the more you do it, the better you'll get. Nobody will notice these things, when it in the air and retracted.

Jan 09, 2012, 07:29 PM
EDF Jet Jam 2017, June 15-18
Kevin Cox's Avatar
Looks good to me!!
Jan 10, 2012, 06:08 PM
Boogie_'s Avatar
Thanks for that guys.
The past few days I've been studying gear doors on various builds. Almost all are thin FG doors. I should have (and may still) made some out of some heavy cloth instead of glassing mine inside and out. The thicker the door, the harder it is to get it past the edge of the fuse when it swings open.
But like Fuzz said I'll be the only one who notices.

Anyhoo, woke up kinda bummed this morning after watching LSU get it's ass kicked last nite.

But! got to the shop and installed the fan and did a test run up.
Spun the ARC 48-1.5 to 1212 watts @ 64A on 5s. Really happy with those numbers.
Duct work didn't flex a bit, solid as a rock.

And my earlier weight check was way off.
While I had the fan in, I taped in all the servos, landing gear and hardware and put it on the scale. AUW is 4.5 lbs.
Only thing missing there is the pilot, canopy & paint.
And I still haven't even sanded the raw glass/resin yet. That will probably negate the weight of the paint.

Earlier I had weighed all the components separately and must have made a mistake adding it all up. Finally an error that breaks my way.

Should have the maiden before the month is out...

Jan 11, 2012, 05:01 AM
Big gov never Works
St. Martin's Avatar
Those are good numbers for that power combo, Julian. I get from 1075(minifan), 1150(het) 1210(WM400) on a 5s 35c 3000. The nice thing is the low amps to get that number.

Jan 11, 2012, 01:01 PM
Fast Jets for Fast times
Lmeano_from_MO's Avatar

The gear door look great and a little extra room never hurts. I am close to looking into the same on the tiger and ordered every hinge available for HK, I think it totaled about 10 bucks for a life time supply. Are you using servos to actuate them or fishing line and spring hinge? I would like to see more detailed shots of what you’re thinking if possible.
Jan 11, 2012, 07:41 PM
Boogie_'s Avatar
The nice thing is the low amps to get that number.
That's what surprised me. I'm pullin' that much in my F-100 on 4s makin' 700-800w.
I think it's the short, straight shot ducting.

Are you using servos to actuate them or fishing line and spring hinge? I would like to see more detailed shots of what you’re thinking if possible.
I'm putting a servo on each door and using this gear door sequencer.
It's really cool (& cheap). And for $3 bucks a servo, rigging up springs and pull strings seems like a lot of work.
The sequencer is almost a must on my Coug though, 'cause the inboard main gear doors are taller than the LG and have to close before it can land.
These are the hinges I used. Along with these horns to attach the push rod.
Like you I also ordered these too. But they are huge. Too big for my plane.

I'm prepping for painting now but I'll get some shots of my set up as soon as I can.
In the mean time, look through some of the pics 90mm composite jet build threads in the ARF EDF section. I picked up a bunch of ideas there.

Last edited by Boogie_; Jan 11, 2012 at 07:49 PM.

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