Makeing a canopy from scratch...

[flying_silverad]

PowderBurner asked me to post some canopy tips for the "Panther" thread in the vendors section so I thought i would post it here as well.


Okay...this could be long.

1. I take a piece of card stock and fold it in half the long way. Using scissors, cut a "half tear drop" shape and unfold. This forms the patterns base. The side profile is usually half of the base profile. If you want a better idea of the side profile, simply fold the pattern back.

Step One

2. With the panther, I laminated 3 pieces of 3/16 balsa just larger than the pattern. Trace the outline of the pattern and begin to remove the material to the line. I use a Dremel or barrel sander on my drill press to expedite this.

Step 2


3. Once the base is complete, then begin shaping the side profile using the "half profile" I mentioned earlier. Take of a little at a time keep eyeing it. Make sure that you don't loose the the center line of the canopy. Once done, wrap a piece of sandpaper around the bidy tube you want it to attach to and start sanding the bottom back and forth. Make sure it's straight by check the bottom of the canopy often.

Step 3

The biggest tip...practice! It's usually takes me about 5-10 minutes from start to finish and anyone can achieve the same results with very little experience. I don't use any special sanding blocks but it is good to really look at canopies of fighters. Here is a great link for "absorbing" some of the lines!!
F-16's

 

[powderburner]

So, basically you did this by hand? (as compared to turning a shape on a lathe and then cutting out the base)
You defined a profile shape as half of the base shape, and used that as a guide to hand-sand the balsa?

 

[flying_silverad]

Originally posted by powderburner
So, basically you did this by hand? (as compared to turning a shape on a lathe and then cutting out the base)
You defined a profile shape as half of the base shape, and used that as a guide to hand-sand the balsa?

Yep, by hand. This is the canopy base pattern...
Base pattern, or top view.

This is the side view or about half of the base.

Side View

No Lathe Required!!

 

[Micromeister]

if you don't mind hard lines canopies can be folding into just about any shape you'd like, sorta like this.

sorry I thought that was the canopy Flat layout. Drat I deleted the file

 

[Ryan S.]

does the really large chunk of balsa affect the way the rocket flies? I thought it might in a small rocket

 

[powderburner]

Originally posted by Micromister
if you don't mind hard lines canopies can be folding into just about any shape you'd like, sorta like this

Yes, that is very similar to what I did the last time. I worked with paper until I got the approx shape I wanted and then cut the flat exterior pieces out of 1/8inch balsa sheet. I added some intermediate internal support webs, glued the thing together from the inside, and sanded the outside to taste. The tough part was wrapping the NC (to which the canopy was eventually attached) with 'backwards' sandpaper (rough side out) and getting the sandpaper down taut on a compound curvature surface. Then I sanded the base of the canopy to fit the NC. I ended up with a more flat-sided canopy shape but hey, it was cheap! (I didn't have to buy a lathe!)

 

[flying_silverad]

Originally posted by Ryan S.
does the really large chunk of balsa affect the way the rocket flies? I thought it might in a small rocket

I'll let you know as soon as tests are complete.

I do know that on my Helix, it had no effect. Of course, I look at the surface area head on and judge from there as to whether a big hunky canopy would produce non-symetric drag. (or should I have said asymetric)

I also have been able to trick rocsim by installing the canopy as a fin...but really thick. In the later case, it seemed to do just fine.

Here is a pic of a future design that has the canopy as a fin. Looks ugly in the photo, but serves it's purpose in design and sim flights.

F19 Night Fighter

 

[Micromeister]

Powder:
I can't say how my cardstock canopies will handle HP, I don't fly that stuff, but CA soaked cardstock has held up well on mirco, mini standard and clusterd LMR models.
RyanS
I don't believe I've seen any negative results on any size model flight with a added canopy heres a 13mm minimum dia. model with cardstock canopy.