HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 19, 2009, 12:49 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Build Log
Carnivore FPV - Scratchbulid FPV sport flyer

After just one flight FPV with a high altitude glider, I'm totally addicted to FPV flying. I decided to make another FPV airplane. This one will be more of a sport flyer. I also have a flying wing started, but I figure I better get the bugs worked out before I try that one.

I have made over a hundred different airplanes, so the airplane part is easy. It's going to be getting the camera set correctly that's going to be a pain.

The first thing I did was cut a wing. I used a USA 49 airfoil. It is mostly a high speed airfoil, but it has fair lifting capabilities. I cut the wing out of blue styrofoam with a home made hot bow. Central chord is 9.25". Tip chord is 7.5". Wingspan is 47".

I then glued the wing cores together with Gorilla glue. Once dry I mixed up 60cc of West system epoxy and covered the top wing with 2 oz fiberglass. Once dry, I'll flip it over and cover the bottom.
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 20, 2009, 02:38 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Fuselage

For the fuselage I'm using my favorite balsa sheeted foam method. It is rigid, durable, easy to work with and easy to repair. It will make mounting the camera and associated electronics very easy.

I simply cut a side profile of the airplane out of 1/8" balsa and glued it to the foam with 3M super 77 adhesive. I then trimmed off all of the excess foam with my hot bow. I will cut the holes for the camera later.
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 20, 2009, 09:19 AM
Live FPV or Die
VRflyer's Avatar
Montreal,Canada
Joined Feb 2002
3,981 Posts
I love that, he built 100 planes already and after one FPV flight, he is addict! Welcome with us!
VRflyer is offline Find More Posts by VRflyer
Reply With Quote
Old Oct 24, 2009, 02:37 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Pan and tilt mechanism

Since it was only going to add about 1 oz of weight I figured I could add a pan and tilt system to the aircraft. The tilt is a simple hinge actuated by a servo. This is mounted to the top of another servo for pan capability.

I cut out a small chamber in the nose for the mechanism. The camera is still behind the nose for some crash protection.

Additionally, I got around to covering the airplane. I made the tail bright neon red so in case there is a video glitch, I might be able to find it easier... I hope.
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 24, 2009, 02:44 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Wing and motor mounts

Well, I found that the airplane was going to be excessively nose-heavy, so I cut my wing mount out and moved it forward 3 inches and glued it back in.

I also fitted the wing with the motor parts today. The motor mounts are made from aluminum strips I got from Home Depot. I drilled holes in them to set the motor mounting plate. I am going to be using Blue Wonder motors from Lazertoyz to power this model. They should provide ample power. If not, I'll upgrade to a rewound BP-21. The speed controls were sunk into the wing 2" behind the wing leading edge.

All of the servo horns are on and ready. All I need to do now is mount all of my servos and landing gear and it's ready for flight I can't wait!

-Alex
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 28, 2009, 03:27 PM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
The airplane is complete. Now it's time for a maiden flight... Wish me luck

I removed the pan system as I figured rudder would be more useful than a pan system that I never use. I did incorporate tilt, though as I use that very often.

I also made shielding out of aluminum foil to keep the servos from jittering. I once made shielding like this for a power monitoring at a power plant. if foil can shield 13kV, it ought to shield against 900MHz.

Specs:
Motors: Twin LazerToyz blue wonders rewound as 13T Wye with 23AWG ML wire ~1420 kv
ESC: dual LazerToyz 30 Amp (yes I know it's overkill)
Battery: 3S 2250 Lipo
AUW: 47 oz, 41 without video equipment
Wing: 48" Fiberglassed foam Gottengen 538
Video battery: 500 maH 3S Lipo
Display: Remzibi's poor man's OSD with GPS

Currently the motors are only running at about 8 Amps each on 7X5 props. I might go to an 8" prop to get a little more thrust. Right now I have 28 oz thrust at 16 Amps. I also might rewind another set of motors to 11 turns which should get me significantly more thrust and speed.
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Oct 28, 2009, 06:00 PM
Houba ! Houba !!
rcmonster99's Avatar
United Kingdom, England, Milton Keynes
Joined Sep 2003
6,267 Posts
Interesting plane.
Looking at the position of the main undercarriage i predict it will rotate with extreme difficulty.
Ideally the main undercarriage should be a very short distance from the CG
rcmonster99 is online now Find More Posts by rcmonster99
Reply With Quote
Old Oct 29, 2009, 12:11 AM
Engineer for Christ
IBCrazy's Avatar
Amherst, VA
Joined Jun 2006
10,567 Posts
Actually I just flew it today. It flew awesome albeit a bit tail heavy. Very stable, plenty quick and manueverable. Haven't messed with the tilt system yet. Was just getting a feel for the airplane. The rudder worked exceptionally well. It rolls in just a little as the tail swings around. This makes for excellent show passes and makes landing much easier when you need to crab it in.

I have to figure out what is causing a strange roll coming out of a loop or hard dive. The plane rolls hard to the right just after the wings go level with the ground. It did this despite having contra-rotating props. Could it be compression at the tail or perhaps a deep stall?
IBCrazy is offline Find More Posts by IBCrazy
Reply With Quote
Old Dec 05, 2010, 07:35 PM
I LIKE WAFFLES....
SENTRY 62's Avatar
Powder Springs, GA
Joined Sep 2010
2,452 Posts
WOW - I love T-Tails. There are LOTS of skills I need to catch up on if I wanna save a buck I see. A lot has changed since I've been out of RC - sorry to bump an old thread but it's still very relevant IMO. In 3 months I've learned to solder as well as airbrush... and I'm sure my iCare ASW28 will teach me some building basics.

Before long I will be trying to tackle scratch builds... but that's months away. You're an inspiration kid.

Sentry
SENTRY 62 is offline Find More Posts by SENTRY 62
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Mini-HowTo Conventional to FPV RC Flyer scrtsqrl FPV Talk 9 Apr 13, 2008 01:42 AM
Discussion Small FPV park flyer MorrisM FPV Talk 38 Feb 20, 2008 01:38 PM
A Sport Flyer Design Snitch7 Foamies (Kits) 1 Jul 03, 2003 11:03 PM
Which sport flyer? Parkflyer Sport Planes 8 Aug 20, 2002 11:53 AM
best sport flyer for Qualcomms?? lemmeatthem Parkflyers 2 Aug 06, 2002 11:03 AM