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Nov 02, 2005, 06:53 AM
can you land on that ?
Check the film of Lake Varesse, excellent !
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Nov 02, 2005, 12:11 PM
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Kuni,
Thank you for that link. Amazing!!!

When the Piaggio 7 lifts off the water I was screaming and had goose bumps...
jimbo
Last edited by Eljimb0; Nov 02, 2005 at 05:45 PM.
Nov 02, 2005, 05:22 PM
Registered User
Martin Irvine's Avatar
Thread OP
Great link!

Martin
Nov 02, 2005, 10:16 PM
Designer/Builder
Jim Young's Avatar

Savioa Marchetti S.65 Outline


Okay Guys,

Here is my "smerged" outline of a S.65. Kuni's link really helped, and the photos of the full size one for some new angles show's that the 3-views I have are not that accurate.

So, based on a 3-view, two model drawings, some CGI artwork, and all the photos I could find, I think I'm pretty close. Let me know what you think.

-Jim
Nov 03, 2005, 02:53 AM
Registered User
Jim,
this looks pretty good to me!
How long do you think until a full plan? And will it be in dxf, when ready?
Im switching for my next project between your baby or a Macchi MC72.

Kuni
Nov 03, 2005, 06:53 AM
Designer/Builder
Jim Young's Avatar
Hi Kuni,

The outline is in AutoCAD, and could be your's now. The next thing to do is scale it to 1/7 to 1/8 scale and start massaging it to make it buildable. Right now I'm just working on it at lunch time, so it will be a few weeks before I have the basic plan. At 1/7 scale the wing span comes in a 56.6" and at 1/8 scale it comes in at 49.5". I have to check the wing area to make sure I'm within Martin's guidelines. I'll offer the plans to you for free if you take a lot of photos and provide feedback. This should make a nice construction article.

I'm planning a foam core wing, built up tail surfaces, foam floats, and built up fuselage (nacelle). The plane will be one piece, except for the fuselage will attach to the wing, or will have a large hatch. Maybe the hatch idea, because the forward struts mate with the fuselage (as the photos show, but the 3-view doesn't). Twin geared AF020's on separate 3S LiPos. I have to make sure the gearboxes will fit in the slim noses, or we'll have to go direct drive. Maybe a couple of outrunners?

Any ideas on the control system? The area where the fuse meets the wing is pretty small, so we may have to put all of the servos in the wing. Right now I'm thinking of putting the elevator servo in the wing and have a flex cable run down each boom to each half of the elevator. A central rudder servo would have pull-pull string down each boom to the rudder. And, two aileron servos out in the wing. The other option is torque rods from the middle, but we'll have to see if there is enogh room.

-Jim
Nov 03, 2005, 08:20 AM
Registered User
Jim,
sounds fine.
For the control issue I would go the scale way: pull/pull cables. Always a dood solution.You could use wing servos, pulleys to guide the cable out to the booms, etc. It is light also.
Another option would be servos in the floats. The back booms from float to tail could be used to hide the snake cables.
I would like to build her in full balsa/ply, because I own a cnc mill. It makes things alot easier. Both sizes would be fine, but I think I will have to build her in pieces. Please can you check the diameter room in the nacelle in either scale, because my own outrunners have a mounting ring of 6cm. This have to fit inside the fuse/nacelle. Two of these outrunners are enough to guide my Savoia S55 save and fast into the air. Around 200-250 Watts per motor.

Kuni
Nov 03, 2005, 12:29 PM
Designer/Builder
Jim Young's Avatar

S.65 Scaled


Hi Kuni,

No problem doing a built up wing. It is constant cord and would just need some structure around the tail booms. Probably just key it into the leading edge. I'm still thinking foam, but there will be a lot of plumbing hanging out of the wing when I bag it, and that may be a problem so we'll see.

I tried 1/7 scale and 1/8 scale. At 1/7 scale the wing area was almost 500in^2, so I'm going to stay with 1/8 scale. Here are some preliminary dimensions:

Wing Span: 49.5"
Length: 43.5"
Wing Area: 380 in^2
Wing Cord: 7.75"
Fuselage Width: 3.4"
Front Spinner: 1.64" (bump up to 1.75" or 44mm)
Rear Spinner: 1.3" (bump down to 1.25" or 32mm)
Floats: 34.29"Lx3.8"W

Ailerons: 16.56in^2 (8% of wing area)
Stab: 86.8in^2
Stab Cord: 7.25"
Fin: 35.52in^2
The large tail area should give pretty docile handling by my calculations.

With this wing area, and a goal of 20oz/ft^2, we have a weight budget of about 53 oz. This should be pretty doable with standard construction. With 300W of power, we're looking at 90W/lb!

-Jim

P.S. Thinking about a NACA2412 or a 23012 airfoil. Any comments?
Last edited by Jim Young; Nov 03, 2005 at 12:44 PM.
Nov 03, 2005, 02:23 PM
Registered User
Hi Jim,

hmm, it seems the 1/8 scale is a bit small for my components. I would like to build in 1/7. But I dont intend to fly over to the schneider meet, so this dosnt matter. Could you scale it to this size for me?
So I could use the batterys and the same size motors as on my S55; money saved. And a 2-2,5kg weight should be doable.
Naca 2412 sounds good; but I have no experience with 23012. Someone else?

Greetings,
Kuni
Nov 03, 2005, 07:20 PM
Designer/Builder
Jim Young's Avatar
Hi Kuni,

The difference between 1/7 and 1/8 is not that much. I'll continue drawing it at 1/8, and scale it up a bit for you. The thicknesses of the formers will be a bit off, but I don't think it will be a big deal. Besides, I'm drawing this in inches, and you'll probably be using metric Balsa!

I got the tail structure and the wing roughed out at work today.

-Jim
Nov 03, 2005, 09:51 PM
Registered User
Martin Irvine's Avatar
Thread OP
Kuni, I have used both those airfoils. The 2412 is a little easier to build. I have liked how the 23012 has worked with a couple of planes so will use that myself.

Jim, I'd use torque tubes for the ailerons as I think they could be made more watertight than two servos.

My Macchi dimensions are:
47" span, 42" long, area 368 sq. in.
Stab area is about 70 sq. in.
Fuse max. cross section is 5.25" X 3.625"

Floats are 30.25 X 4 X 4.125 white foam covered with glass cloth and epoxy.

Wing is white foam, CF reinforcement, covered with 1/16 balsa

Fuselage will be white foam covered with 1/16 balsa formed with ammonia and glued on.

That's the current plan at least.

Martin
Nov 03, 2005, 11:26 PM
S-55 lovers: have you seen this? http://www.airwar.ru/enc/other1/s55.html

Scroll to bottom for some really clear pictures.

Then there is this site: http://www.seawings.co.uk/s55mangal.htm

Terry
Nov 05, 2005, 06:15 PM
Registered User
I would go for Servos direct before the ailerons. It is watertight enough, especially with a rib wing. Can dry out easily.
Jim, can you send me some scaled files next week, maybe the floats? I can mill next weekend, and so the construction phase could start. I would need two days or so for fine constuction (stringers, holes, etc.). Did you make some brainstorming of how to make the float-to-fuse-booms? Carbon rods or steel wire? I would go for steel wire, because there is nearly no space to cross carbon tubes. With wire bond you can screw it to the underside of the fuse.

So far,
Kuni
Nov 05, 2005, 10:50 PM
Registered User
MISTERSCOTT's Avatar
Guess I'll have to make a larger one. 24" ws
John
Last edited by MISTERSCOTT; Nov 05, 2005 at 11:01 PM.
Nov 06, 2005, 08:59 AM
Designer/Builder
Jim Young's Avatar
Cool Curtis, John.

Hi Kuni,

I've got the plans basically done, I have to clean up the fuselage formers and do the float cross sections. Everything is still laid out like a 3-view, and I can send it that way or give you a wing plan, fuse plan, etc...

For the main float struts, I'm thinking music wire with balsa or aluminum streamlinings. For the rear struts I'm thinking of sandwiching 1/64 plywood between balsa. This will be lights and the 1/64 ply will key into the booms and the floats. The booms I have drawn as 1/16" plywood on each side and 1/4" balsa in the middle. The balse will be carved out to route the control lines.

I watch some of the video of the site that you posted, and saw some rought landings and the floats ripped off. Anyone got some good ideas on attaching music wire into foam core floats?

-Jim


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