On line models

I am about to finish a Vector .40 wing.

I'm thinking of building a profile w.it, but putting the thrust, wing and stab/ele centerlines online (or inline, i mean, all in the same line

Would it be worth the try?

In Christ,

Ion, there have been a few world class planes built "inline" in the recent past. Xain's Skywriter (World Champion), Werwage's Geo XL 1st version, and the second is inline except for the thrust line, and his "little Junar" is all inline. I have the plans for these three, and I believe that the KA-10 (Kolesnikov) is also inline. Mr. Werwage said that they do have a couple of different characteristics from the traditional set up. I built and flew in several contests a small inline Junar w/ OS 40VF on pipe which I really enjoyed until pilot error left me with a perfect wing (and nothing else useable!).
It turned equally, and was very easy to trim.
Go For it!
Bill

Check your Eliminator plans. You'll see an inline model!

Crist Rigotti
"A driver trying to be a pilot."

>Check your Eliminator plans. You'll see an inline model!

Crist. my beloved,

Why in heavens am I intersted in inline models?

The KA-10 is anothe one in my list.

God bless you!

In Christ,

Ion

BTW, the Eliminator is turning out pretty nice, straight, rigid, 1/8" horns, 37 oz with engine and pipe and tank.

My target get it below 42 oz.

>I am about to finish a Vector .40 wing.
>
>I'm thinking of building a profile w.it, but putting the
>thrust, wing and stab/ele centerlines online (or inline, i
>mean, all in the same line
>
>Would it be worth the try?
>

I built a few of these, a long time ago (before I really knew anything about it), but I never cared for the way they felt around neutral.

Why?

If you want a first-class, modern, .40 sized PA ship, build it like its designed. There is a fair amount more work to build it as a full fuse--the benefits are HUGE!

Curt (very satisfied SV40 flier)

>Why?
>
>If you want a first-class, modern, .40 sized PA ship, build
>it like its designed. There is a fair amount more work to
>build it as a full fuse--the benefits are HUGE!
>
>Curt (very satisfied SV40 flier)

I second the motion.

Building an inline model in a profile can also cause problems. You have the weight of the gear below, and nothing to balance it out above. We did this with the "Das (Ugly) Stunter" design, but it was designed with an upright engine, so the engine, muffler, and tank are above the thrust line balancing out the gear. Building the same plane with the engine inverted proved to be really "interesting" (that is, if you like to watch your plane lean in as it flies around the circle).

Also, you will find that the controls are not totally linear with an inline configuration as might, at first, be expected. You will find that with the tail elevated, propoprtionately with the size of the horns, that you will have a much more linear response (flaps to elevators).

There are reasons most planes are not designed as inline.

Hi len,
Oh boy, am I gonna step in it now.
Curiousity is killing me! The planes I mentioned are all world class planes, the Skywriter having won the World's (regardless of the judging issues, etc.). "Several of "The Man"s planes are inline.
What is the down side of building/designing that way? I have flown both types, and although I never expect to be in the Walker Cup fly off, I have and will fly in the NATS from time to time and like to build several styles of planes.
Curious
Bill

>Hi len,
>Oh boy, am I gonna step in it now.
>Curiousity is killing me! The planes I mentioned are all
>world class planes, the Skywriter having won the World's
>(regardless of the judging issues, etc.). "Several of "The
>Man"s planes are inline.
>What is the down side of building/designing that way? I
>have flown both types, and although I never expect to be in
>the Walker Cup fly off, I have and will fly in the NATS from
>time to time and like to build several styles of planes.
>Curious
>Bill

The down side is what I mentioned. The slight tracking difference (between elevator and flap) is probably not a big deal. Well, let's say it isn't a big deal. with flaps and elevators moving in opposite directon, there shouldn't be any flap blanking, especially with longer tail moments. However, the vertical balance is a real issue. With a "normal" set up, thrustline slightly above the wing, but with the engine pointed down and tank beneath, and with the tail above this, there is weight to balance out the weight of the gear beneath the wing. Put the engine inline and the tail inline and invert the engine (and add a pipe beneath) and you have a real problem with vertical balance.

A side mounted profile would be less of a problem, but a problem nontheless. On the planes that you mention, how long ago were they designed, and what/when did they win? And were there other design considerations to overcome the vertical trim problems or did they just live with them?

>On the planes that you mention, how
>long ago were they designed, and what/when did they win?
>And were there other design considerations to overcome the
>vertical trim problems or did they just live with them?

I am not real sure about the Skywriter, it was either the '88, '90, (?) WC's he did win twice IIRC. And the set of plans I have show an
inline set up with side mounted engine. Tom Dixon loosely based his Praxis on this design.

As to the Geo XL and "inline Junar" (Bill W.'s words) they are realitivly old designs coming from the early '90s. I guess he never "won" anything with these, but I wouldn't mind a second place in the fly off myself!

I had totally forgotten Casale's Columbia. (Old NATS winner)

Of course, I am not totally aware of all the inline designs out there, the "engine" review guy from STUNT NEWS spoke of one used as a test bed/Old contest plane.

Thanks for the ideas!
Bill

Leonard's right about the control non-linearities using standard horns. With an inline setup, you should build custom horns with neutral offset angles to compensate for such problems.

[photo not recovered: 3e69bb3870f12ad5.jpg]

"Let not the sands of time get in your lunch."

I have Zhang Dong's drawings for the Skywriter, and it's not "in-line". The offsets are smaller than typical, but there. I imagine he keeps the engine just slightly (3/8"?) above the wing C/L to preserve the vertical CG with the side mounted engine.

Jimmy Casale's 88/89 Nats winning Spectron Columbia was an all in line ship.

Regarding Ion's original question . . . I'd drop the side mounted engine to 3/8" over the wing on the profile ship, and put the stab 3/8" to 1/2" above the thrust line.

RC

>I am about to finish a Vector .40 wing.

Great wing!

>I'm thinking of building a profile w.it

If YOU want/need a profile, build a profile. Many of us still want/need a profile. Why build a built up fuse plane if you want a profile?

>Would it be worth the try?

If it is an "experiment" as you allude to, go for it. You just might like it, and learn from it.

Ion,
AS the original message was somewhat sidetracked (and I had a part in that, sorry) it just might be a great learning experience as to the characteristics of set ups that might not be traditional.
Bill