building a glider

[hello183]

With some smaller gliders, I would just move a coin up and down its nose, until I found the lucky spot where it balanced right when I tossed it. So I was just planning on getting the CG on the spar and adjusting the weight more from there.
@quorneng I was thinking about launching it off my deck when it was done. But there is also a huge pit that we use for sledding in the winter. I might fly it there.

 

[Piotrsko]

So right now it looks like he has glued the tail on and the wing and the tail would sit at 0/0 decalage. So the only way to adjust the incidence (decalage) is to shim the front of the wing - assuming he will attach it with rubber bands. Say with a piece of posterboard or 1/16 balsa to start.

I'm a fan of tape doubled over on itself on the trailing edges. 2" wide masking tape makes an acceptable trim tab

Are the first flights off of this deck or into the pit or is this a later on flight?

 

[hello183]

I made this new nosecone out of a foam block. This foam is a bit more porous, but I can clean that up later. The curve on the bottom is a bit better now too.

@Piotrsko I might try to fly it in the backyard till i get the glide right, if it flies well then, then I may go up to the deck and do it again, and after that, I may go to the pit or some hill and see how it flies.

 

[hello183]

If I were to reinforce the nose, would fitting a balsa firewall between the front pieces of the fuselage be a good idea?

 

[quorneng]

Yes. Your fuselage has very limited resistance to "lozenging". A balsa bulkhead would help and it would also give something to stick the foam nose block too!

 

[danskis]

To reinforce the nose to make it more crumple resistant I would sheet the inside of the fuselage (or outside over the covering) to behind the wing. All four sides - depending on how much weight you have to add. You can sheet it with foam board, poster board or balsa sheeting.

It looks like you already have some sheeting on the top of the nose. I would add that to the other sides.

 

[hello183]

I cut out a firewall and put some filler on the nose. I am thinking of using wall paint to paint the nose, and then using clear enamel to seal the entire thing. Can wall paint work or do you think I should consider something else? Here is a picture.

 

[cyclone3350]

I cut out a firewall and put some filler on the nose. I am thinking of using wall paint to paint the nose, and then using clear enamel to seal the entire thing. Can wall paint work or do you think I should consider something else? Here is a picture.

View attachment 231468

Yes, U can use latex "wall" paint. I use it on all my models including my large scales. Never tried a sealer, but I've seen it done one a large scale twin 310 that was sprayed with latex and sealed with a clear coat used for cars.

 

[quorneng]

Wall paint (Emulsion in Uk, Latex in US) being water based is foam safe. It has good covering ability but it is relatively heavy and is not really damp proof so any moisture will make tissue sag. Car type clear lacquer is not foam safe so you are relying of the thickness of the wall paint to stop the spray solvent to evaporate before is permeates through the paint and attacks the foam.
Quite possible using several light spay coats and allowing the clear lacquer to dry hard (6 hours) between each coat.
I use it on quite a number of my planes built from foam sheet.

Not a full high gloss but smooth with a 'sheen' rather than the dead matt of the original wall paint.
The smooth surface is largely the result of using lightweight filler (also water based) and gentle sanding with fine grade paper
Foam itself is completely water proof so any water based product has no adverse effect. Very different if used on a tissue covered structure.
I hope this helps.

 

[hello183]

@quorneng the paint will not be going on the tissue, only the nose block. I was not planning on sealing the nose block with lacquer, but instead I was going to seal it with Rust-oleum clear enamel. Do you know if that attacks foam?

 

[cyclone3350]

@quorneng the paint will not be going on the tissue, only the nose block. I was not planning on sealing the nose block with lacquer, but instead I was going to seal it with Rust-oleum clear enamel. Do you know if that attacks foam?

I think the Rust-Oleum will attack the foam. I've used this with success on foam. It is a WB acrylic. Spray in light coats @ first with about 12 - 18" of distance. The clear coat won't attack the foam but the propellent used will. I've also used the satin clear on tissue to give it that doped look. This one was built from depron & tissue covered with the satin spray.

 

[quorneng]

hello183
As cyclone3350 says it is the solvent and/or the spray propellent that attacks the foam. Some foams are resistant to some solvents but In general expanded polystyrene foam is about the most sensitive.
The only guaranteed safe foam paint is one that is water based and uses air as the propellent if it is sprayed.

 

[hello183]

I was able to paint the nose with acrylic paint.

I also glued the firewall piece to the nose. It is a friction fit to the front of the fuselage. I did this because I want to drill a hole in the center of the nose to put in balance weights, but I didn't want to make it noticeable.

 

[hello183]

The fit of the nose is actually a bit loose, so I think I might glue it on instead.

 

[hello183]

I decided to put a nickel on the back of the nose. It flew so far, just on a light hand toss. I launched the next time with my hand a bit higher and it flew farther than I ever imagined it would. It kept on flying until it reached the neighbor's yard and then the wind pushed it to the right and it flew up their yard. But the covering started sagging because I did not seal it so I will buy the krylon soon.

 

[danskis]

Congratulations on your successful flight!!! When you get around to throwing it off of something higher I would put my name and phone # on it - but only if you want it back. You might consider putting in an RC rudder control at some point.

 

[Piotrsko]

Congrats. I am suitably impressed for a first try. Need to find a big open are and really see what it can do. Might also want a bit of turn added so it flies in a smaller space

 

[hello183]

I was able to find matte krylon at Walmart and I was able to spray the krylon today. It is looking fine right now. The parts are drying now so I will take a picture of it when it is dry.

 

[danskis]

Since you're designing pure free flight planes you might start looking at ways to include a dethermalizer. This will help ensure that you get your plane back.

 

[Piotrsko]

Seen dethermalisers fail in monster thermals. Add name and contact info to plane