Dave G

My Feedback: (1)

Do a "search" on ebay for "propeller" or "propeller opener". I got mine there for a few bucks plus shipping.
Just for fun, I've spun it with the motor. It's definantly NOT balanced! The little Mulligan just stands there and vibrates. It's only for looks anyway .

Sorry Bembo9, don't mean to take up your space talking about my little bird. They're a great little project for a change of pace. Number 1 rule... build light. Every gram counts. Have fun!

zoomzoooie

Hi guys

I used to build these Guillow kits too. Who didn't
I used to sheet mine with 1/32" and or 1/64" balsa fitted in between the formers and strings to keep the outline. I would stay away from 1/16" sheeting. It adds a lot of extra weight you can afford. You could sheet over the stringers and formers if you like. It would save a lot of time. I then covered it with water wetted silkspan, (being stronger then tissue), use a misting spray bottle, , and a mixture of white glue and plastic model cement put on thinly. This is like glassing in miniature and adds al lot of strength and very little weight. I then used Aerogloss dope for finishing. You could complete the entire model this way.

As for the flat bottom Guillow's airfoil. I would change this to a more scale like chambered airfoil to add some thickness to the wing. Maybe something like a NACA2411 airfoil. This will help to make for a better flying plane and should help to slow it down some what. The secret of coarse is to keep it as light as humanly possible and even so the wing loading has to be insainly light to get it to fly closer to scale in these small ones.

I have recently been introduced to the venerable little Norvel .074. Besides being such a great little power plant they and their muffler fit nicely inside the cowls of a lot of planes of small size. I think the P-40 is calling for a Norvel .061.

I would go with ailerons too in a design like the P-40 with low wing high dihedral type.

I got some Micro point hinges for my project and I think they will work fine for any scale hinge set up. Robart make micro retract if you have some weight to add after you find you built it way to light... lol. Actually I scale my project up from 24" to 32" wing span just so I could have retracts, flaps, ailerons,elevator, rudder and throttle.

2 cents add!

ZZ

clively

ZoomZoooie,
Do you happen to have a picture of what that airfoil looks like? I haven't completed this project yet (kids, wife, etc..), but I was already considering building a second wing ( with ailerons )after I get it in the air.

Also, I sheeted 1/32" over the stringers and formers. You mentioned that you sheet between them. Quite frankly, I thought the plans were crazy when they mentioned sheeting in between, but that could be my own inexperience. It seems to me that cutting all of those little pieces and fitting them would add time to completion without adding strength. Am I wrong?

Lastly, when adding ailerons/flaps, what percentage of the wing is devoted to moving control surfaces? What I'm getting at is that a 29" wing doesn't have a whole lot of room. Do I just need a about 4" for ailerons and another 2" for flaps?

Thanks!

CafeenMan

I'm wondering where you're going to fit all those servos. As far as flaps/ailerons go, basically make them half and half.

A barndoor aileron is usually about 20-25% chord and 25% span. So make them and turn what's left into flaps.

As far as the fitting goes, if you don't, then your plane will be too fat. It might not be noticeable, but your right about it being tedious. I would do it just around the nose back to the wing or so and then leave the rest alone. If I was dead set on sheeting the entire fuselage, I would bite the bullet and spend some hours cutting pieces to fit between the stringers.

zoomzoooie

Clively

Here is the NACA4211 Airfoil.

Yes I did sheet between and it does take a lot more time but it does add less weight this way. All the stringers and formers will not have add 1/32 sheeting on them and the strength is still just as strong as sheeting over. I know it won't add a significant amount of weight but it all adds up in the end. It is also more work to get an even smooth surface but once you get the hang of it you will see it's not so bad.

I also saw you mention a 1/8" balsa spar. With the full sheeting of the wing such a heavy spar is not needed. But if you want the strength, you might try changing, and/or relocating the stringers in the thickest part of the cord top and bottom, to 1/8" sq and add 1/16" balsa shear webs with vertical grain to them. This will give you much greater strength and add less weight.

One of my problems is I like true scale. That being said, true scale very seldom will lend to a good flying model, specially in the small size and high wing loading like that of your P-40. For the best flying and most controllable plane you will need to use a full span aileron. For this you could keep the scale outline and include the flap outline within the aileron.

If do want to use flaps and ailerons then your best bet would be to use a computer Tx and 2 servos for the use of flaperons and flaps and ailerons separately. Don't forget about the added weight of the extra servo. In any case of the above you will end up with a very fast flying airplane.

I would recommend using elevator and full span ailerons. You should end up with a good controllable model using scale flap and aileron outlines as full length ailerons. Use the lightest possible servos and the smallest lightest battery pack.

Try a sample of my covering technique. You will be surprised at the strength to weight ratio.

If you are like me and want full 6 channel functions I would recommend enlarging the plans to about a 36" wing. I would use the full sheeting over method for this size.

Hope this helps a little more.

ZZ