ALOFT: AH-100 Build (new title)

[G-man]

"The Wing is the Thing"
I wish I could remember where I learned that.
Perhaps it was an RC Soaring Digest article title.

RC Soaring Digest magazine

I love that sailplane - so much that I built three of them for winch launch, and sold two of them to flying buddies.
The third led to a magazine kit review article, fully incorporating Pete Young's "Olympic II Building Hints and Tips"

https://charlesriverrc.org/articles/design-and-construction/kit-modifications/sailplane-modifications/olympic-ii-hints-and-tips/

 

[G-man]

Because the flight performance of the Oly-2 wing is so well-suited to my taste and skill level in sailplanes,
and to me the 100-inch, 2.5 meter span size is the sweet spot of portability and performance
I began building a fourth, from scratch, over the drawings, and midway through the build, decided to finish it as an electrified version.

Might as well incorporate a smoother, better-looking fuselage, so or my fourth Oly-II build
I turned to Wayne at Aloft to see if he could supply a fiberglass fuselage.

Wayne sent a Topmodel PRELUDE fuselage.

 

[G-man]

The "Electro Sailplane" looks and flys just great. It's very near the top of my list of favorite RC planes.
Is it my imagination, or is it really true that with its longer fuselage it flys smoother than the Airtronics original design?

 

[Wayne]

Great to see you posting this up here!

Want to tell them what you guys are building this winter?

 

[G-man]

" Want to tell them what you guys are building this winter?"

I sure will. Lettuce get a little further along with the build. Make some progress and get some construction pics.
HINT: A three-guy group build project, and we are beyond happy to have Topmodel fuselages that Wayne imported for us.

 

[G-man]

OK. Here's more of a hint.

 

[Hank GB Z]

Cool. A Sig riser with a glass fuse.

Hank

 

[Mucksmear]

"The Wing is the Thing"
I wish I could remember where I learned that.
Perhaps it was an RC Soaring Digest article title.

RC Soaring Digest magazine

I love that sailplane - so much that I built three of them for winch launch, and sold two of them to flying buddies.
The third led to a magazine kit review article, fully incorporating Pete Young's "Olympic II Building Hints and Tips"

https://charlesriverrc.org/articles/design-and-construction/kit-modifications/sailplane-modifications/olympic-ii-hints-and-tips/

“The wing is the thing” was a newsletter dedicated to flying wings / tailless aircraft. I think part of rc soaring digest

 

[Raymond Gaskins]

Great to see you posting this up here!

Want to tell them what you guys are building this winter?

Wayne,
Do you have any more of the Top Model Prelude fuselages in stock? If so, I would like to purchase 2 of them.
Raymond

 

[G-man]

Wayne,
Do you have any more of the Top Model Prelude fuselages in stock?
If so, I would like to purchase 2 of them.
Raymond


Raymond,
Welcome to the revolution.
// Dave

 

[Raymond Gaskins]

Wayne,
Do you have any more of the Top Model Prelude fuselages in stock?
If so, I would like to purchase 2 of them.
Raymond


Raymond,
Welcome to the revolution.
// Dave

Wayne,
Do you have any more of the Top Model Prelude fuselages in stock?
If so, I would like to purchase 2 of them.
Raymond


Raymond,
Welcome to the revolution.
// Dave

Hi Dave,
Beautiful planes; I love flying these types of sailplanes when I desire relaxation instead of knocking knees!
Raymond

 

[Wayne]

Some inspiration for a new wing design.

So, let's discuss some issues we might want to tackle:

The Oly II wing could flutter at speeds.
The film tended to pucker between the wide rib spacing.
Wing tip blocks were extra weight and really only for locks.
Too much dihedral at center panel.
Spoilers not really needed.


Benefits:

SLOW and stable.
Cored thermals well.
Simple to build thanks to flat bottom airfoil.

Anything else you would like to discuss for the new wing?

Can I get some measurements of the polyhedral angles you guys like?

Might I suggest an airfoil change, this a rather modern mostly flat bottom airfoil we might want to try:

Here is the original:

I think we will still have an easy to build wing and still very forgiving in flight.

We can try a prototype with this and always change back to something pretty easily if need be.

2 piece wing design I assume? We would make this modern with carbon rod and 3D printed fixtures. Strong and easy!

 

[JohnT]

Olympic 99, my first RC Plane! Oly II in my current fleet. Watching this with interest.

John

 

[G-man]

- Consider also the Sig RISER-100 wing for ideas on designing the new Aloft Hobbies wing.
Note that the Sig design incorporates prominent turbulator spars in front of the main spar.

-100-inch span is the sweet spot for me on the performance/convenience continuum.


The Oly II wing could flutter at speeds.
I've flown both.
I can reliably get my OLY-2 wing to flutter in a gentle dive.
I have not had it happen on my RISER-100 wing.

The film tended to pucker between the wide rib spacing.
This does not bother me.
Neither OLY-2 wing or RISER-100 wing have D-tube leading edge.
Film sag presumably did not trouble either designer.

Wing tip blocks were extra weight and really only for locks.
Well, looks are important.
Isn't that why we're replacing the boxy wood fuse with he sleek fiberglass fuse?
Changing the tip shape will make the new wing look different than the OLY-II sweep up tips.
But we still want it to look pretty.
See also Pete Young's take on OLY-2 wingtip shape.
http://www.charlesriverrc.org/articles/kitmods/peteyoung_olympiciihintstips.htm

Too much dihedral at center panel.
Not that I have noticed.

Spoilers not really needed.
Not needed if you have adequate size LZ.
And the motor permits go-arounds.

Can I get some measurements of the polyhedral angles you guys like?
I like Airtronic's original angles.

Might I suggest an airfoil change, this a rather modern mostly flat bottom airfoil we might want to try:
Fine by me. Let's give it a try.
Is that the Phillips Entry, as on Ed Slobod's PARAGON and GEMINI MTS?

2 piece wing design I assume?
Heck yeah, for ease of storage and transport.
I find three piece wings cumbersome.

We would make this modern with carbon rod and 3D printed fixtures. Strong and easy!
This sounds good. And modern.

// Dave

 

[G-man]

Wing tip blocks were extra weight and really only for locks.
I think the fancy-dancy original OLY-2 wingtip shape was intended to reduce drag from tip vortices.
Who was it who taught us: "The most important factor in wingtip design is how far apart they are."
Dave Thornberg in The Old Buzzard;'s Soaring Book?

 

[Wayne]

Yes, to pretty wing tip. Not an issue.

The suggested airfoil is an AG-35 from Drela. I'll read up on it, I saw someone else used it on a modernized Oly-II build and it does appear to be a good choice.

 

[Wayne]

Ok, Got some time to work on this some. This is just a starting point. No wing joiner or wing tip details, etc. This is a bit of a mix of different aspects. It has a little OlyII, Riser and Bob Marin PussyCat mixed together with the AG35 airfoil.

For now I am using the AG35 across the entire wing. We could blend to the related 36, 37 versions towards the tips.

Do the polyhedral angles look right? Currently 8 degrees at the center and 9 at the tips.

Top view, pretty much the same rib spacing as the Oly.

Here is where the Pussycat comes in. It has a lower longeron.

I'm suggesting 1/4" x 1/8" spruce spar caps with 1/8" shear webs. Longerons are 1/8" balsa and leading edge is 1/4" x 3/8" balsa, it should require very little shaping, but lots of contact with the rib and some strength to combat hangar rash.

I debated using a round dowel for the leading edge, but none of us liked that all that much. They tend to do more damage should you have an accident.

 

[Wayne]

With center sheeting:

Let me know what you hate and what you like.

 

[Wayne]

Here is another variation that would be easier to build. We remove 2 of the longerons and replace it with a single "comb" that would be laser cut for a great fit. Also makes the rib jigging ever so much easier.

Here I have removed the shear web and the front comb so you get an idea of how the ribs fit into the webs and comb.

And now with no spars or ribs:

 

[Sandman]

I've been looking to build a powered floater with a built up wing for some time.
I happen to have a Sig Riser 100 kit collecting dust. Wayne provided just the ticket with the Prelude fuselage.
Wayne's offer to produce a new built up wing design made it all the more enticing.
G-man has built the Riser combo, plus an OLY2 version. and put them both thru their paces.
A lighter wing design would complement the light weight Prelude fuselage.
The Riser plans show Phillips entry on the rib profiles, the birch leading edge dowels could be CF.
I assume the turbulators are a structual integrity issue, aside from preventing sag in the covering.
With so much wing surface area, maybe the weight is not the only issue to chase?
Support from vendors is so lacking these days, dealing with Wayne has been a joy.