idealer

My Feedback: (4)

I just ordered a Mini Funtana and want to convert it!

I was thinking of a Norvel 15-25 or maybe a 30 4c

Here are the specs on the plane:
Wing Span: 37 in (940mm)
Overall Length: 37.75 in (959mm)
Wing Area: 314 sq in (20.3 sq dm)
Flying Weight: 20 oz (567g)

What do you guys think? I dont have a clue how to calculate. But I want unlimited verticle

Bipe Flyer

A 30 4C weighs half as much as the suggested flying weight. It would have unlimited vertical, but it would make the plane pretty heavy. A Norvel .074 would probably do quite well if you could keep the weight down. A BigMig .15 would give you unlimited vertical without adding too much weight.

combatpigg

My Feedback: (3)

The NORVEL .15 is supposed to be very powerful! I have an OS .15 LA and it can haul 27 ozs straight up to heaven. The quoted weight for the FUNTANA is set up for electric, so it might weigh 18 ozs or less with an .074 NORVEL. Hmmm.....I don't think you can get brute 3D power from anything .074 and under, if you want a "little muscle plane", go with the .15! Let us know how it works out.

idealer

My Feedback: (4)

I think I am going to go with the 15... I will post updates...

gizmo8012

My Feedback: (15)

please do update, I am considering this as well, thanks!

L

Dukester

My Feedback: (31)

Anyone know what the bare airframe weight is?

Duke

Bipe Flyer

Good question Duke. Flying weights of electrics vary a lot due to different battery options.

obsession

I just picked up my funtana the covering and fiberglass is some of the best I have seen I cant wait to start on it but will be after the holidays iam sure, Iam looking at the norvel 15 for power. Happy holidays to all

Dukester

My Feedback: (31)

Bipe,

That's exactly what I was thinking. Looking at the manual off the website is looks like the plane is about 16.5 oz with radio gear installed.

So if you went to the Norvel .074 @ 2.7 oz, plus a tank (2 oz tank should give about 10 minutes of good flight), mount, and extra servo/throttle linkage you'd probably end up 21ish ounces. For a wing loading of about 9.2 oz/sqft.

If you went to a .15, you'd be 5.7 oz for the motor and need a slightly larger tank (3 oz for 10 minutes), bigger mount, and throttle servo/linkage. With the .15 you'd be about 24-25 oz. Loading of 10.9 oz

Probably my choice would be the 15 just to be able to run the 8" prop with authority. Either way it should still fly ok.

Duke

idealer

My Feedback: (4)

Got it started today, very fun looking plane...

I had a new 074 in the garage so I will try that first, It had a 7x3 on it and I though of trying an 8x4??? to much prop?

I was going to build up the firewall but I want to see how it flies first, I maybe end up with the 15 but I thought I would go the light route first...

Dukester

My Feedback: (31)

I really like the looks of it. IF I hadn't just bought the Mig . If another planes shows up in on the couch for sure.

Duke

AndyW

My Feedback: (1)

Idealer,

Thanks for the thread. Mine's on order, still waiting. I WAS going to install a Norvel .074 on diesel to swing a bigger prop, more slowly with more torque. I also have a dieselized Norvel .15 but I suspect that will be overkill. Just hope the covering is diesel fuel proof. If not, I'll run it as glow.

The plane that is using the .074 has some 320 squares and weighs 23 ounces so the Mini-Funtana sounds like ideal using the .074, glow OR diesel.

Can't wait to get mine.

combatpigg

My Feedback: (3)

That's a beautiful and intricate plane! Imagine scratch building all those formers! I think it will be interesting to know what the .074 can do on it. The engine looks pretty tiny on there. I think the APC 7-3 is the best choice for thrust and throttle response. I am curious to find out how well that tank mounting and fuel line routing works for ya, it goes against everything that I've ever been taught, but you've got it in there like you know what you're doing..the big FUNTANA with a SAITO .72 is the most impressive combo [in that price range] that I've ever seen at the local field. This little one is like the big one in that it looks very lightly built without any wasted material.

Andrew

It is a pretty plane!!

I agree with CP -- if you're planning a lot of vertical work, unless the clunk falls to the back, how do you intend to maintain fuel pickup?? My experience with smaller tanks has been that the fuel pickup tubing needs to be pretty flexible just to get the clunk to move from bottom to top, but generally, it will not flip to the front unless I have an unintended 1 point landing.


the "other" andrew

idealer

My Feedback: (4)

.074 was not enough verticle for me so I am gonna try the 15...

AndyW

My Feedback: (1)

Idealer,

On your .074 can you advise prop size and brand, fuel, rpm and all up weight?

Redneck Shaun

My Feedback: (1)

Idealer did you fly it with the .074?

matchlessaero

The absolute most you can weight you can hang (3d style) from an .074 is about 15oz's, and the ideal weight is about 13.5.... Any more than 15, and you really will just have a sport flyer. For best 3D performance out of the .074, I run 30% nitro and an APC 7-3 prop. The engine really does not run well if you swing anything bigger from it....

For what its worth, I would highly suggest going with a hot .15 on this bird instead of the trusty .074...

AndyW

My Feedback: (1)

Hi Matchless,

I had an interesting expreience before the snow moved in. I had been flying the sport plane pictured in my post with the Norvel .074 on glow and at an all up of 23 ounces and an APC 7 X 3, I was quite happy with it. Lots of aerobatic capabilities. Then I dieselized it and used a Tornado 8 X 4. With that prop on diesel, the plane would hover at full bore. Then I tried one of my precious Cox 8 X 4 greys. On the Tornado, the .074 did 10.6K. The Cox gave me 12K and now I can just climb out of the hover,,, barely. Still, an improvement, and the flat out speed improved noticeably. I'm wondering if Idealer might have got what he wanted if he had tried a Cox 7 X 3.5. I'm convinced that the Cox greys are superior to anything out there, including the APCs. In fact, the same engine would only do 9.3k on an APC 8 X 4.

matchlessaero

Andy, I agree that the Cox props are wonderfull. In fact, I use the 6-3 (black) on my .061 powered Edgelings and Half-Wits. It revs better, and the 'pull' difference in the air is staggering!

I have not tried the Cox 8-4's on a .074 powered Edgeling, but I have trouble believing that it would make enough of a difference on glow.... Keep in mind however, that my goal is to hover at about half throttle[8D]


I guess I won't say never, until I try one on one of my Edgelings....

AndyW

My Feedback: (1)

Matchless,

You're way ahead of me, I need full throttle to hold a hover. That certainly vindicates your 15 ounce criteria, and I agree. If you want to mimic the big, TOC kind of flying, that's what you have to aim for. [8D]

No, an 8 X 4 on an .074 on glow won't cut it. BUT, I'm flying the .074 as diesel and that makes a world of difference. [sm=thumbup.gif]My fuel tank is rigged with neoprene and that's good for glow AND diesel. I've been routinely switching from glow to diesel trying out different things. Props are one of those things and on the same day, glow pushing an 8 X 4 can't cut the mustard compared to hauling the same lumber on diesel. Am I hooked on diesel?[sm=lol.gif] Big time. There's just something about the way diesel can lug big props that you get to like in a real hurry, especially for those verticals. Flat out ain't bad either.

Here are my figures on testing a variety of props on the same day on a dieselized .074.

Cox: 12K to 4.5K Best on verticals and flat out speed.
Taipan: 11.3K to 4.5K Third best.
Tornado: 10.6K to 4.5K Second best.
Graupner: 10K to 4.5K Poor verticals, flat out not bad
APC: 9.3K to 4.5K Worst of the lot in all respects. Even throttling was affected,,, have no idea why.

The APC has a very thick symmetrical portion of the blade about 1/4th of the way from the hub. Looks like a lot of wasted blade. So, I carved away at both blades in this area to a slightly undercambered shape. That gave me an extra 500 rpm with a slight improvement in performance.

Although the Taipan was better in the static test than the Tornado, in the air that changed. In the air, it was only on par with the Graupner.

I'm far from the shop right now but later, I'll post pics of all the props in question and you can see the dramatic difference in design between the best (Cox) and the worst (APC),,, and the others.

I got so charged up about this I called Cox to find out if they'd do a production run on all the greys for me and then I'd go into the prop business. Unfortunately, they're not even sure if they have the molds anymore. [sm=crying.gif][sm=thumbdown.gif][sm=crying.gif]

I think I've got your Half-Wit plans and I hope to do one up and run a dieselized .06. I've run the 8 X 4 Tornado on it and it turns it strongly. You can almost FEEL the torque. So far, nothing has broken, which says a lot for Norvel's crankshafts. The rod is another matter, I bent a rod in the air on a dieselized .06 when I tried an 8 X 4. So, this one has a custom made rod with a rectangular cross section. If I have a problem with the crank breaking in the air, I've got an .06 rigged up with an MP Jets crankshaft to try.

Throttling was affected and I had to go back to a stock barrel. Now it throttles solidly and reliably with the adjustable airbleed. However, tilting the test rig back to simulate a strong climb produces a flame out. This was cured by adding an exhaust extension. This provides more pressure to the tank and delivers the fuel when going vertical. Interestingly, but not surprisingly for diesel, adding the exhaust extension didn't affect the top end much and the engine didn't overheat.

Man, you guys have just GOT to try diesel. Big props, lots of torque, strong verticals. No other way for me, anymore.

AndyW

My Feedback: (1)

Matchless,

Here are the props tested on the dieselized Norvel .074.

From the top to the bottom.

APC modified
APC stock
Graupner
Taipan
Tornado (black)
Cox

Again, the modified APC has had the inner blade area undercambered as near to the hub as you can go. Hope its clear in the pic.

Most props don't follow true pitch all the way to the hub. The Taipan and the APC do, the Cox, Tornado and Graupner don't. In theory, the prop that follows true pitch the best, ought to be most efficient. Yet the APC, famous for true pitch, is the worst of the bunch compared with the Cox.

What might we conclude from all of this? Airfoil, blade shape and blade area are the critical factors affecting prop efficiency. Not to say that the APC philosophy is flawed. I think they're just too shy in blade area in some sizes. At least for 8 X 4s running on diesel engines. I do have 5.5 X 2s and 6 X 3s that work well on .06s when you need a prop that allows the engine to spin up real fast, as in glow operation.

phuffstatler

My Feedback: (20)

Which prop were you using, the 8x4 or a 7x3? What fuel? My LHS has several of these on the shelf, and I was wondering which engine to use. For that matter, how well does the plane fly?

phil in georgetown

idealer

My Feedback: (4)

I was flying it with a 074 / 7 x 3, I will be putting a norvel 15 on it with an 8 x 4 and see what I get out of it.

phuffstatler

My Feedback: (20)

I've got one now, and I picked up a AP .15 and several props for it... We'll see how it all works out...

phil