ChrisSpad

I saw a 120 US at our last flyin, and, since i had a 25cc homey laying around i decided i'd build one for myself.

Here's the full scoop.
Wingspan:72"
Chord: 17" (3" ailerons)
Spar height: 2" (spar-foam with wood stiffeners centered at 27.5% chord).
Fuse length - 43" (plus rudder and engine). Fuse started at 48", and the nose was cut down until the plane balanced.
Engine: indescript 25cc homelite, traded the original orange CC Edge 540 for it. Right now, its swinging a 17x8 apc at 6900 rpm.
AUW: 12 lbs even.
Wingloading: 22.6 oz/ft

Servos: 8:
One on each elevator half
One high torque on the rudder
one on each aileron
one on each flap.

Mixing:
Crow (aka airbrake)
Outboard ailerons and/or inboard ailerons, inboard and/or outboard flapperons, full span flaps/full span ailerons, and ailevator (mixes aileron into the elevator)

Here's a couple of pics, at some point, i am going to put some flames on it, but not until i am sure its worth the effort.







Once i cut the fuse down to get it to balance, it ended up looking alot like a Magic.

All the pics here:

http://users3.ev1.net/~cdjump/main/ultra25/gallery.html

matchlessaero

I really like it. Despite the shortened nose, it looks very well proportioned..

Can't wait to see it fly. Next Weekend? Have not seen you out in a while... (but then again, I guess I would have to be out there to know.....)

ChrisSpad

hey Jeremy,

I haven't been out on the weekends much lately. Been going to the lake alot, and quite frankly, its just been too darned hot. I work outside most of the time, so its hard for me to drag myself out when i could be sitting in the ac. I have been flying though, been during the week, late in the evening.
I am gonna take it out this afternoon late, i think.
Did you get moved yet?

masterlink

Chris,

Other than the picture sequence; do you have any instructions and or notes on the finer details of building this plane? Is so, I sure would like to see them. I am going to build a giant SPAD and you have given me some neat ideas. Masterlink

ChrisSpad

nothing other than the pics. There's really not much to it. The fuse is almost identical to a spadstick, except scaled up a bit, and i used 3 1/2" pvc for formers. There's 3 formers, one for the engine to mount to, one at the leading edge of the wing, and one at the trailing edge. The spar, is kinda odd, its 1x2" foam, with 2 pieces of 1/4x1/2" fir or spruce polylgued into it. It made a very stiff, very light spar. I think it'll be plenty strong, but i really won't know until i stress test it good in the air.
The key to building a successful giant spad is to keep it light, even moreso than the little ones. 3 or 4 ounces here or there doesn't sound like much, but it adds up in a hurry, especially considering the engine weighs almost 5 lbs itself. 7 lbs aint too bad for the airframe, and radio gear, i don't think.

Jagdgeschwader 26

My Feedback: (4)

Nice job, Chris. I have a 31cc Ryobi just looking for a nice firewall to call home. What percent chord is your cg?

Finishing up a couple of Debs, then on to something bigger...

Flight report would be welcome.

later,

ChrisSpad

Yep, its a keeper. Took it to the field late this afternoon, did a range check with the engine running, and took off. Took a couple of clicks of rudder trim, and about 3 clicks of elevator, and it flew hands off no problem. First flight was awesome. I did some loops, and rolls and harriered it a bit. Flies great.
Not quite enough power to hover, but plenty of power to be a whole lot of fun.
Next flight i set the airbrakes up, and applied them, and it stops right now. From full throttle to creep is a very short distance. Plus, with the full span flapperons, and high rate elevator, it'll loop end over end almost (until it bleeds off all its airspeed).

Its still a touch noseheavy, as inverted requires a bit of elevator, and it doesn't flat spin well, but it was still a blast to fly.

I forgot to get pics at the field, but, here's one from earlier this morning. The only thing i've added since this pic is a couple of cross braces on the landing gear out of a piece of 2-56 pushrod, to help stiffen em up just a bit.

I was really worried about the landing speed with the symmetrical wing, and 23 oz wing loading, but, it turned out to be a non issue. Its not a trainer, but lands no hotter than a normal dps does.
I couldn't be happier with the way it flew. I am gonna add about 2 degrees right thrust in it, and readjust the cg a bit, as its still a tad noseheavy, but, i'd have no problem throwing it in the truck just like it is, and flying the snot out of it.
Did i mention i am thrilled with this plane? I am.
I'll put together some basic dimensions, and whatnot, but no plans per se. The plane is too easy to build, and built with standard spad technology, so, if you've built a few spads, you should have no problems building one from the drawings, if anyone's interested.



more pics here:

http://users3.ev1.net/~cdjump/main/ultra25/gallery.html

and the original build thread here:
http://spadworld.net/viewtopic.php?t=4127

Captain351

Chris

A few questions. What prop are you using on your Homey 25.

Where exactly is your CG now and can flight equipment be moved to make it less nose heavy. If you were going to make another one would you move the firewall back even more.

Thanks!

ChrisSpad

cg is the middle of the spar right now. Wing is symmetrical, and the spar is centered on 27.5% mac.
No, i won't cut the fuse down any more, i don't think. Its stubby already, and i may want to put a lighter engine up there at some point. The 25 homey is heavy. 4 lbs 13 oz, with prop and adapter.
As far as shifting the gear, i think i'll have to add a little lead to the tail for this engine. Shouldn't take more than 3 or 4 oz, max, as it doesn't need to go back much.

Prop is a mas 18x8 thats had the tips cut down to a 17x8. I am gonna try an apc 18x6w on it at some point, as well as an 18x8 apc, for a bit more thrust. Not that it really needs it for normal flight. But, its not enough to hover, thats for sure.

Jagdgeschwader 26

My Feedback: (4)

Hi Chris,

At the risk of being a pain in the neck.........it needs s-t-i-c-k-e-r-s.

Just a friendly reminder...

ChrisSpad

Um, i wonder if you guys ever read before you open your mouth....

From the FIRST post:

And besides, stickers are for those who have more time than i. I'd rather be flying.

Kraut

My Feedback: (1)

Nice plane Chris! Glad to hear that it was successful! Woohoo!