Critter,

That will give you a straight cylinder. I have a feeling that the ring will cool part way down also, and it may be hard to keep straight.

An easier way to do this, and also produce a taper, would be to simply cut out a circle template for the nose in cardboard, or aluminum flashing or thin ply, etc.

Then cut out an oval section for the tail end, same way.

Spray a very light coat of 3M 77 on the ends of your blank. Stick the templates on.

Set your foam cutting bow in a vice with the wire end up, and running horizontal.

Cut the foam blank by holding it in your hands and rotating it over the foam bow. You have to keep the cut even at both ends. Don't let one end get ahead of the other. Let the weight of the foam keep it on the wire, don't push -- use a delicate touch. Don't run too hot. Go slow.

This will make a conical section fuselage -- at the end, an oval cone.

For complex curves you can't use this method, you have to shape by hand, but it's also not hard:

Draw out your top view on a squared up foam blank. Then cut it out and save the cutoff pieces.

Reassemble the new blank and cutoff pieces with tacks of hot glue. Draw the side view on this re-assembeled block.

Cut out the side view. Remove the cutoff pieces. You now have a square fuselage but it has tapers all around.


Now to make it round sectioned.

To do this, you take an even amount of material off of all the corners by eye with a sanding block to make an 8 sided cross section.

Then take these corners off to make a 16 sided cross section.

Finally round by eye.


This is how we make perfectly round tapered masts on boats without a 25 foot long lathe (there is no such thing in boatbuilding -- people always asked me when I had a boatshop -- where is your lathe -- how do you make masts?).


The last method is very fast -- longer to explain than to do in foam. A sanding block takes material off quickly and evenly. The disposable sponge type used for smoothing drywall works well.

This has the advantage over the first method that the tapers can be curves -- like on a real airplane, not just conical tapers.

This is how I did the model of the Gee Bee Z (pictures at post # 834 in this thread) which has very pronounced compound curves that eventually end in a flat section at the rudder.

One final easy way to get a cylindrical fuselage in foam ( and I'm working on a plane this way now) buy a swimming pool "noodle" at Wally World -- a kids toy float -- cylindrical foam -- it's EPE foam, basically indestructible. Will need some skewer stiffening for most projects.


Try your idea first -- if it doesn't work to your satisfaction, these others might help.