stunthanger.com
Building Tips and technical articles. => Building techniques => Topic started by: Crist Rigotti on January 27, 2025, 10:17:55 PM
-
I want to make a balsa canopy for my latest stunter. I have several ideas on how to accomplish this. But wanted to see how other people have done it. It will go on a rounded top of the fuselage which has molded balsa skins of 3/32. It'll be 8 inches long and about 2 3/8 wide at the fuselage. It should go down from the top of the molded fuselage about 1/2 inch.
Do I cut away the molded top or do I sand in the rounded top into the bottom of the canopy? Of course it'll be hollowed out and such. My question is how do fit the canopy to the model. I'm used to using PETG canopies and all I did was cut them out and sanded them to fit the rounded tops of the fuselages.
-
I cut the appropriate sized block and hollow it to let it sit on the front block without any rocking. Last time I used the side of my belt sander and that got me pretty close to let it sit on the front block. After that, I will cut the basic outline I want for the side view. Then I place it on the plane and start carving
-
Thanks Matt.
-
Just a thought. If you want to make a balsa canopy, and I understand why you want to do this, you have to carve the outside to the shape and style you want. You are pretty much there to where you have a plug. You could then pull your own canopies, and/or use the plug to lay up a fiberglass or carbon canopy that might be lighter, since you are counting grams?? Something made from 1/2oz glass would weigh almost nothing.
Type at you later,
Dan McEntee
-
I do the same as Matt. I carve it to fit the rounded top block.
-
Thanks guys. Look like I carve it to the rounded top block!
-
Crist I do canopies and cowlings the same way. Make yourself a side view pattern. Then make vertical laminations from some thickness of light wood you have on hand-anything from 1/4" to 1/2". If the canopy was to be 2" wide then four pieces of 1/2" would work or eight thicknesses of 1/4". Thinner pieces will form closer to the curve of your top block. Then I'd put some parchment paper on your rounded fuse top and start pinning and glueing each lamination in place starting from the center. When dry you pick your new canopy up to remove the paper. You can then finish carve, sand and hollow the block and glue in place. I little blue putty around the joint and you are good to go.
Dave
-
Great idea Dave! Thanks.
-
You could carve the canopy from blue foam and overlay with 'glass & z-poxy.
-
You could carve the canopy from blue foam and overlay with 'glass & z-poxy.
What's the weight of that type of assembly?
-
I sometimes use commercial bubble canopies. Fitting to a rounded fuselage can be difficult. This is how I do it.
tape a piece of sandpaper to the fuselage, sandy side up.
Slowly rub the canopy against the sandpaper. until no gaps show between canopy and fuselage.
Fasten canopy using canopy cement, just a spot in front, and rear. Then glue each side separately.
Hint: Plastic canopies easier to handle if you put two or three layers of masking tape on them. Makes them nice and stiff for sanding.
Finished canopy can be painted, if you want a "balsa wood look". (no carving required)
-
Thanks Floyd.