What do you typically do to cap off the ends of the wing? I was thinking of two options
a piece of really thin balsa might help protect the ends of the wings(LE & TE) from the enevitable ding or just a piece of depapered foam board camfered around the edge.

On a side note, I'm just trying to build a plane with whats available to me. At some point in the future I will probably build one out of something a little more expensive if I plan on keep it for a while. I think part of foamies is building a plane out of stuff that is available.

I just cap them with another piece of sheet foam usually... or cut a bevel and then cap with foam so the end looks less "squared off".

Cheers.

Same here - depapered foamboard, trace wingtip against it, cut out, sand to conform, hot glue on wingtip taking care to invest all the exposed paper edge in the glue seam.

What about sweptback wing, what's the technique in making those..because the foam board is square..

[QUOTE]What about sweptback wing, what's the technique in making those..because the foam board is square..[/QUOTE]
Shape the foam before you fold it, or fold it and then shape it.
Or use a modified method of bending a separate top skin down to join with the bottom skin.

Don't you have problems with hot glue in the AZ sun? In Michigan I have heard of joints opening up if left in the car or even out on the ground in the sun. I know keeping the colors light and using only high temp glue would help, but most have given up hot glue for Gorilla glue or other PU glues.

I've certainly heard of hot-glued planes here in Oz reverting to kit form when left in a car in the sun.

excellent job eperimental air,now i know how to make a wing without hot wire

Making a wing tip for a foam board wing is pretty basic and has very few limitations. The bigger limitation has to do with the gluing method you use. You can do the butt joint, but it is the weaker option. Still works fine, and better if the glue is stronger than hot melt glue. A lot of folks butt the wing end against a piece of thicker foam board, like the 1/2" or thicker insulation foam board. Once the insulation foam is trimmed flush with the outside edges of the Readi-Board foam core, it can be difficult to see the joint, unless the foam types are a different color and the glue used is a contrasting color. The other option for a wing tip is to use a thicker foam board and cut the foam to fit snuggly inside the thinner foam to help define and preserve the airfoil shape. Then add another layer or two as butt joints and shape according to your desires. A butt joint done in this manner, if properly glued, is harder to remove by a cart-wheel landing, or other type crash manuever. As long as the thinner foam remains undamaged, it is an easy repair to cut the thicker foam material off as needed and replace with same.

I do know the hot melt glues can get warm enough to soften again and the joint can become un-glued if stressed enough, but ... a little heat (not too much) from a plastic film trim iron and it is often possible to reassembly without adding more glue. A very interesting benefit of using hot glue. Keep in mind you don't want to take an aircraft model from a hot car and throw it into the air as quickly as possible. Instead, give the model about 10 minutes to cool off, or rest time (assuming the outside temperature is below 110 degrees F) and stress the joints a little to see if there is a problem while checking the COG and trim settings. The standard stress test is to bend the joint, or pull on it with around 3 pounds of pull or bend pressure. That isn't much, but if the model is smaller than a common park flyer, you might use a bit less stress.

It is also wise to carry a 100-140 watt power converter to plug the hot glue gun into if your car or truck battery isn't old and run down a bit. Some folks carry an extra charged up car or truck battery to the field as part of their field battery charger and quick repair tool kit. Foam board cannot normally handle the high temperature melt hot glues anyway, so most of us are using the standard hobby grade hot melt glues and glue guns. There are low temperature glue sticks that start to get soft around 110 degrees F and the sticks look limp after 95 degrees F, but it takes more heat to melt the glue sticks enough to adhere to foam and soft woods. That would suggest if your car doesn't get above 100 degrees F, the model assembled with commonly available hot glue will be fine with a 10 minutes cool off period. Of course if the outside temperature is getting above 95 degrees F, you can bet your car interior is much warmer. Think about the "Don't leave your kids in the car" adverts and you will see the connection. If a lot more people flew hot glue assembled foam RC models, the adverts would include a note about the flyers left in hot cars, vans, or trucks coming apart and getting warped.

Got one wide wing done.

Instead of doing a 30" wing I did a 20" wing to keep from having to put two pieces of board together.

Going to make 2 more wings the same way then join them. I trimming the ends up on my table saw so in the end I will have a 58.5 inch wing with a 12 inch chord.

Heh...Chucked the wing piece across the room it flies straight across the room before it loses speed and stalls out. Kind of excited to see what the entire wing will do. not sure what your joining method is but I'm probably going to use Epoxy just because it is the strongest stuff I have.

I have gorilla glue, but I'm not to impressed with it. Dunno if I using it correctly or not

Originally Posted by Whoopz

... I did a 20" wing to keep from having to put two pieces of board together. Going to make 2 more wings the same way then join them. ... in the end I will have a 58.5 inch wing with a 12 inch chord.
... I'm probably going to use Epoxy just because it is the strongest stuff I have. I have gorilla glue, ... Dunno if I using it correctly or not

Not sure of the math, but if I connected three 20" wing sections together, I am pretty sure the wing would be 60" long. Maybe I am not reading this right, but that sounds like a glider wing to me. Epoxy is a great way to connect wings, but I would use a bit of glass clouth also, or at least some coffee filters to make the joints stronger by placing the reinforcement all around the joint (outer surface, flat, 2"-3" wide strip). I bet you are planning on doing that also.

Gorilla glue, or any other brand of urathane glue tends to foam up a bit, but with a little pressure applied until it sets, makes a strong joint and fills minor gaps well also. You do need to keep an eye on the expanding of the foam glue and wipe it down with alcohol on a paper towel more than a few times if it is getting out of the joint. Pressure on the joint is the key until the glue sets. I use clamps, sandbags, block weights, or whatever else I can to put pressure on the joint without warping, or smashing the parts. Normally the glue sets within 30-45 minutes, and cures in around 24. Once cured, the foam or wood joint should be plenty strong, but it is best to leave the joint stress free until cured.

Well...I'm trimming edges on a table saw so the wing itself with be slightly less than 60" I pick a set amount of 1/4 inch of each edge. So the wing should be about 58 1/2 inches when I'm done.

I hadn't thought about reinforcement. ON the last wing I made I used only tape as a reinforcement. I hinges the bottem side applied the epoxy then closed it up and let it set. I guess I could do it that way then reinforce it.

We'll see how it turns out. so far so good though :-D

I like this method. It seems more work than a KF airfoil but it looks worth it. I will be trying it.

I wonder if this could be adapted to do a symetrical or semi-symetrical airfoil? What if after making the leading edge bend you were to cut away the paper on the lower side in front of the foam spacers. That way when you bend it over and glue down the top side it pulls up the bottom a bit. I guess you could work it into a curve before you start glueing the top.

Anybody tried it?

How about tapered wings? I guess all it would really take would be to taper the thickness of the spacers.

Originally Posted by Whiskers

[QUOTE]What about sweptback wing, what's the technique in making those..because the foam board is square..

Shape the foam before you fold it, or fold it and then shape it.
Or use a modified method of bending a separate top skin down to join with the bottom skin.[/QUOTE]

I haven't worked with other-than-rectangular wings but I hope we can figure out some ways to do it. Pre- or post- fold shaping as above seems like a good idea. I just wanted to keep it really simple, and the rectangle suits my needs so far. Joining swept wings with a spar may prove to be even more complicated, but we'll see.

Originally Posted by bz1mcr

Don't you have problems with hot glue in the AZ sun? In Michigan I have heard of joints opening up if left in the car or even out on the ground in the sun. I know keeping the colors light and using only high temp glue would help, but most have given up hot glue for Gorilla glue or other PU glues.

Haha! Spontaneous thermal disassembly is a definite possibility in AZ. I've been lucky with hot glue so far, but then it's 3 minutes from air-conditioned home to field, and we have decent shade. But you could kill a plane pretty quick if left in the car for sure!