Ernie Misner

What could they be thinking if the leading edge bluntness is a problem and they made the newer 50X the exact same way?

Thanks,

Ernie

T.W.

Ernie: Is the 50 exactly the same as the 40? I would have thought that the wing problem would have been spotted before the 50 went into production. But I can't believe that either model was actually designed this way. I'm assuming that the problem arose during the production run - maybe to save the cost of a couple of lengths of balsa! Does anyone have any background information on this?

Tony

mikedsilva

i fixed the problem and i didnt have to fix the leading edge either!





i sold the plane to a mate....

Ernie Misner

Usually a blunt leading edge is GOOD for 3D type (high alpha, etc., many different angles of attack).

Apparently too much of a good thing.......?

Ernie

T.W.

Mikedsilva: Before I fixed my Funtana's wing I wouldn't have even given it to my worst enemy, let alone sell it to a mate! Is he still your mate btw

Maybe you're right about the blunt leading edge being "too much of a good thing" Ernie. Even though I fly some pretty wild maneouvers I still like my models to "fly nicely" when I ask them to do so - and the rounded-off l.e. it now has certainly allows this. The next mod will be to install a slightly larger engine. I'm using an ASP 61 4-stroke at the moment and it's not quite enough power . . . . close, but no cigar!

Tony

dickj

My Feedback: (1)

Hi fellow Funtana 40 owners My computer has crashed but I am back with a new faster one now! I will attach the pictures of the wing mod that I gave Tony and emailed to others. I hope you modify and then enjoy your Funtana as well as I do. Makes a completely new airplane. The new Funtana 50 does not have this mod in it, however, they did incorporate the mod in the new larger Funtana. My designer friend Wayne showed them this mod at the TOC in time to make the production run. I just love this plane. I fly it on a Saito 91 with an APC 14X3W prop. Does all the 3D stuff and lands real slow and no stalling. You can now do a harrier landing if you have this mod in yours. Just cut the covering off at the leading edge to front of rib and remove the leading edge. See their original bluntleading edge in picture. Then add on about 5/8ths piece of balsa to leading edge and fashion according to the picture. Notice the contour changes from the wing tip to the inboard end. Really this is quite simple to do wiht a plane and sanding board. Then cut a piece of white Ultracote that folds back over the leading edge and iron on. You will think it came from the factory like this. Dont disturb the color scheme even.

Good luck! PLease post how your model flies after the mod so we all can see.

Thanks, and sorry for the late pictures.

T.W.

Hey Dick, thanks for posting your pix - that's great! My modification was done in "almost" the same way as yours. But I didn't need to stick any new covering over the leading edge (yet!). I peeled-back the original covering and taped it out of harm's way before fixing the leading edge, and then ironed it back over the new l.e. once the job was done. There was "only just" enough covering to do the job so I suppose that I may eventually have to fit a narrow strip of white over the front-end as you have done - if the original covering starts to lift

But just like you Dick, I've found that my Funtana is a completely different aeroplane now that the wing has been modified. It flies really nicely, does some great 3-D stuff and yet can still be flown very slowly - without wanting to stall and "flick!" I now really enjoy flying it, so thanks again for tipping me off about why it was such a bad flier in the first place

Tony

Ernie Misner

Dick, which photo shows, and how does the leading edge contour change from the root to the tip? I assume the tip is slightly more blunt which would fly at more radical angles of attack and stall last rather than first.

I wonder if a person could cheat and simply add turbulator or trip strips someplace along the leading edge.

Thanks for the great info!

Ernie

jasonflier

hey all
im runing a funtana as well but with a saito 82a and it knife edges perfectly

does anybody know the full dates of world war 2
it's for a project
thanks
jason

T.W.

Hi Jason. Glad your Funtana works ok for you. Take a look here for data re your project: http://www.worldwar-2.net/

Tony

T.W.

Ernie Misner: Great idea about the turbulator strips, but would they work when the model was inverted too? With 3D-type flying you really want the wing to work the same both ways up. Has anyone tried this? And has anyone tried fitting them on both sides of the wing - probably not 'cause I just know it's going to turn-out to be aerodynamically non-viable . . . . maybe. I'm really interested in this idea though and will file it away for some investigations at a later date (next winter maybe). Thanks

Tony

Ernie Misner

Hi Tony, the trip or tubulator strips (they are used on gliders a lot and break up "laminar" airflow over the airfoil) just need to be tried. Probably 2 layers of 1/8" pinstriping tape would work. For the Funtana I think I would put one on top and one on the bottom of the wing, just behind the leading edge somewhere. This might trick the airflow into thinking the leading edge was not such a blunt shape. Fuel and oil might tend to take the strips off over time though but it would be easy enough to put new ones on. I even saw one hand launch glider guy that used pinking shears (zig zag pattern) to make his trip strips out of masking tape. Like this, they are just used on the top of the wing about 20% of the way back as I recall. Then there was the guy who put the trip strips just on the wing tips to help with tip stalling tendencies.

Ernie

T.W.

Ernie: That's very interesting indeed. And I will definitely try turbulator strips sometime. However, my Funtana doesn't need them since I modified the wing. But I will remember to try them the next time a new model stalls too readily

Today I had another good flying session in 15+ mph, and very blustery, winds. I was delighted with the way the Funtana handled the tricky conditions today and I'm confident that the model will be comfortable flying in 20+ mph winds - and I can hardly wait to try as flying in a good blow adds more interest - and so much more of a challenge too

I'm getting more and more confident with the Funtana every time I fly it now that it's stall is far more predictable. I even had enough "faith" to pull-off a harrier landing today. I also flew a couple of knife-edge 8's and a cool-looking elevator using spoilerons linked to the elevator. I really love flying this model now that it flies so well

Tony

Ernie Misner

Awsome report Tony!

Ernie

AGR413

My Feedback: (1)

You guys don't know how happy I am to find this thread. I blew my budget for a long time and have been disapointed with the stalling and slow flight characteristics. She has always seemed like the girlfriend that would kiss you one minute and then step on your crotch the next. I will look at modifying my LE.

Q: does this mod help with hover?

T.W.

Hi AGR413 - I'm also pleased that you found this thread, because the more dodgey Funtana wings we can get "flying right," the more it all seems sort-of worthwhile to have had the problem myself and to have discovered how to fix the problem, if you see what I mean. If you send me an email address which will accept a large-ish file I can send you a "step-by-step" illustrated explanation of exactly how I modified my wing

"Does this mod help with the hover?" you ask. Good question really. If you're asking about "hovering on the wind" (ie: not hanging completely vertical on the prop, but using engine power "and" the wind to hover at a "nose-up" angle of attack) the answer is absolutely yes. This is because the wing will fly at slower airspeeds, instead of just stalling-out. I hover on the wind quite often now that my wing works, but prior to the mod it just wouldn't do it at all

But if you mean "does this mod help with prop-hanging," the answer is no, because prop-hanging doesn't require the wing to fly at all. However I can confirm that the mod really helps the recovery from prop-hanging, where the exit is any way but straight up. My recoveries are 1,000% better with the wing mod as the plane will now start flying immediately I push- (or pull-) out of the hover, instead of "dropping like a brick" until it's picked-up some flying speed

Hope this helps,
Tony

Chrispeace

"As the designer of Hangar 9’s Funtana, Sebastiano’s goal was to create a smaller version of his Funtana S 1.20, which he uses for 3D practice, and still have the same flying characteristics and the 3D capability of his large TOC Katana S. One distinctive feature of the Funtana S .40 is the tapered, constant-thickness airfoil. By using an airfoil section at the wing’s center that is 11.5 percent of the thickness of the chord and a thicker, 20-percent airfoil at the tip, Sebastiano has been able to create a model that has stable low-speed characteristics much like his giant-scale aerobatic plane, yet it still flies very precisely. —Rick Bell"

This is a direct quote from Rick Bell and came from Jet Thompson's Horizon Hobbies article:

http://www.horizonhobby.com/Articles...ArticleID=1358

I wonder if either gentleman would like to comment on this thread or indeed if the Funtana 40's father, Sebastiano Silvestri, might have thoughts on the issue. Would be nice to think that having sold everyone the idea and in many cases the kit, that their interest didn't stop with the cheque!

Gentlemen?

Chrispeace

http://www.horizonhobby.com/Articles...ArticleID=1487

Link to the review of the F90. quote" Stall characteristics: this is one of the most stall-resistant planes I have flown; it just keeps slowing down and pitching nose-up."

Does anyone have a picture of the airofoil of the F90? It looks sharper in the review pics than the F40. and is universally accepted as a better flyer.

Could someone take 5 mins to post shots of the F90 wing x-section for comparison with the F40?

PJ_TankPilot

I rarely read a topic entirely that is this long but this one was an exception. I have a Funtana 40 that flys like crap. I fiddled with the CG for a while but gave up. It exhibits all the bad characteristics described by TW. About every 3 months, I take it to the field and fly it. It is work, not fun.

Several people have offered to buy the plane because it looks nice but I wouldn't sell this plane to an enemy.

I have always suspected the wing but assumed I knew less than the designer.

I think I now have the fix. Yippee

T.W.

Good words Chriss. I am prepared to bet a large proportion of my annual modelling budget that original design for the H9 40S's wing looked pretty-much like dickj's modified wing. I'm also guessing that the "too-blunt" leading edge came-about duriung the production run. Can you imagine the scene, in some Far-Eastern factory unit where most of today's ARTF models are being put-together: "Excuse me Mr Production Manager, we've run out of leading-edge stock for the H9 Funtana 40S." "Never mind, just stick some of that 1/8-inch strip on the front of the ribs and then plane the corners off - no-one will notice the difference!" Or maybe an accountant thought he could save a few cents per wing by using thinner leading edge material (this is more probable actually). But one thing I am certain of is that no matter how the situation arose, Sebastiano Silvestri sure didn't design nor test-fly "my" original Funtana's wing

Tony

T.W.

PJ_TankPilot: I can understand your interest, seeing as you also seem to have got a "bad-winged Funtana." You describe exactly howI felt about flying my own Funtana before I did dickj's wing mod. I can guarantee that you'll love the way it files after you've done a little work on it. If you'd like an illustrated "blow-by-blow account" of how I modified my wing just send me an email address I can send it to

Regards,
Tony

dlwood

Tony:

Could you send me a copy of your mod?

[email protected]

Thanks in advance.

T.W.

Hi dlwood. I don't have a copy of it where I am right now unfortunately, but I'll send it to you as soon as I get home again (around 4 or 5 hours from now). I was told that I needed to do the mod by dickj (see earlier in this thread) so it's not really "my" mod. And as Dick would probably be quick to point out: it's not really "his" mod either. It was first calculated, and then effected, by Dick's aeronautical designer friend, Wayne (three cheers for Wayne! - he's got my vote for "man of the year!)

Tony

T.W.

dlwood: My email is now on its way to you. Please feel free to ask if I've not made anything clear enough for you. And do let us know how you get-on with your Funtana once you've finished the mod

All The Best,
Tony

daveopam

My Feedback: (9)

I have to be a stick in the mud and say I am not convinced. No doubt it will make it sport fly better but that's not how I fly mine. I don't have the 50x in the air yet. However my 40S would do things I have yet seen repeated by another plane. There is a video of a good F50x flight on this forum. I watched it and saw sport flying. I have had my thumbs on a F90 a few times. It is more stable in Harrier and knife edge. But when it comes to Water Falls ,Elevators ,Parachutes and Walls. The F90 is not as extreme. Mine would snap with the wrong inputs and you had to be gentle with the elev on high rates. IMHO it was worth the trouble.
I wish a spare wing didn't cost $100. I would modify one and try both. As it stands though I think I will stick with the original design.

David