SPA3D and an O.S. 40 LA

[Viper Pilot]

I'd like to make the 3D, but don't knopw the Wingspan for an O.S. 40 LA. What about wing chord??

Any help out there??

I've seen that "hot" 46-47s have a WS of 36", but can't find info for a "plain Jane" 40.

VP

[FrankC29]

The wing chord stays the same for different engine sizes, that way cg is always the same. For a .40 I believe the recommended wingspan is 34". 32" will also work fine, and roll a little faster. Plain .40's do not weigh much more than bb .25's.

[David Hogue]

I havent built one yet, but thought about it for an la .40 I have lying around. Seem to remember the plans say to reduce both wingspan and length..yep, here it is:

http://www.spadtothebone.com/SPAD/SPA3D/Instructions/instructions.html

Quote: For a strong .30 class engine or bushing .40 to .46 build with a 34" span x 34" fuselage rail. For a strong .20-.30 sized engine build with a 32" span x 32" fuselage rail.


I am guessing the lighter engine offsets the shorter tail, and places the cg in the same spot, since there is no change to the wing position, according to the intructions.

later,
David

[Viper Pilot]

Thanks for the speedy response.

"A-building I will go"

Never 3D'd yet, but I think I'm ready.

And this plane looks like the way to learn. Not worrying about trashing the plane will help alot.

Viper

[FrankC29]

Yes, I should have mentioned that. The fuselage length does go down as the wingspan goes down. The wings chord, however remains the same.

[nate 1001]

I built a spa3d with a 40 la and it just barely has enough power to hover but is still loads of fun. I shortened the wingspan to 34" and the length to 34"

[Viper Pilot]

From what I could find on SPADtothe Bone, this would be a feasible SPA3D for the 40 LA:

30" wingspan with 19" chord (apparently the chord should ALWAYS be 19").

A fuselage length of 30".

Seems small to me, but it IS a weak engine!!

Two more questions:

1) Should the wing be pushed all the way forward to the motor mount??

2) What would the CG be?? Still 6" behind leading edge??

Viper

[bigstik40flier]

A TT.46 pro would be better than the 40 LA and its only 15$ more

as for the were the wing should be about 1 cm away from the motor mount, yes the CG should be the same. the photos show the wing 1 cm or so away from the motor mount

im going to maiden my spa3d this weekend will let ya know how it gos

[nate 1001]

i pushed the wing up against the motor mount. helps keep the wing from twisting around the u channel

[FrankC29]

My 32" SPA3D flies with an OS25FX. It doesn't have a lot of pull out ability, but other than that does the job. I did however leave off the landing gear, which save a few ounces and also minimizes the chance of damage on a nose in. The CG can be 6" to 6.5". I had it at 7" for awhile, but that's a bit too squirelly I think. I have a video of mine flying on my site if anyone cares to see.

http://home.earthlink.net/~plasticwings

[Hoover]

I'd like to make the 3D, but don't knopw the Wingspan for an O.S. 40 LA. What about wing chord??

Any help out there??

I've seen that "hot" 46-47s have a WS of 36", but can't find info for a "plain Jane" 40.

VP
I used an RJL 61 on my spa3d...plenty of oomph for it now!!!!
:)

[Viper Pilot]

Buying a new engine is not a option.

I already have an OS .40 LA.

Never got started on the SPA3D, because of prior building commitments.

Guess it'll be this winter before I get to it.

[Billy Haynes]

How about just subtract 15% from all deminsions. I built one for a guy that was go'n to use a LA .40, but then he decided he didn't want it. I ended up selling it at a swapmeet, so I don't know how it flew ect. I built several 36" ones for TT Pro .46 & had a blast whith them. Several of us at the field have debated on how well it could be used as a trainer with a longer tail moment. 7 of us have the SPAD Dagger & combat with them...... their a blast also :D

[Blackhawk3D]

I have an MDS .40 (Very strong for a .40 size I think, runs rock solid). My fuse U channel is 32.5 inches long, I got that as a size when I was thinking of the QHor I think, I don't remember it was like 2 years ago, I have had it since and want to make one now. what wingspan should I use?