designing rc plane
03-21-2020, 05:59 PM
#1
Junior Member
Thread Starter
Join Date: Mar 2020
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
designing rc plane
How do you make the curves of the airplanes tops at the back of thes olane its perfectly curved. how can i make curves like this out of foamboard?
second Question- what should the wing width be in relation to the wingspan?
second Question- what should the wing width be in relation to the wingspan?
03-21-2020, 08:44 PM
#2
No help on the foam board question, I've just started to explore building with that. Although I have designed and built planes for over 50 years....
As for the second question...ummm, that really, really quickly gets you in to the vast field of aerodynamics. The width to span is called "aspect ratio". It can vary a LOT, depending on the type of flight you are designing for. Look at sailplanes vs jets. And no, it's not just slow vs fast....
Since you are posting in the Beginner column, best advice - STEAL. Look for a plane that is pretty close to what you want yours to look like. Best if you can find a picture looking down from the top. From a printout, or even on your monitor, measure the wingspan, then measure the width ("chord" in aerodynamic terms). Let's say you get a 5" span, and 1" width. That aspect ratio is 5:1
If you got oddball numbers, like a span of 6.75 and a chord of 1 3/8, divide both numbers by the width to get the right side of the ratio down to "1". 6.75/1.375 = 4.9 and 1.375/1.375 = 1, so pretty close to 5:1
For your design, if you want your wingspan to be 50", divide that by the "5" in the 5:1 ratio. Width would then be 10". Don't worry about being all that precise.
Get this book, as an introduction to aircraft design, if you want to know more about the whys. One of the best intros to design ever published:
As for the second question...ummm, that really, really quickly gets you in to the vast field of aerodynamics. The width to span is called "aspect ratio". It can vary a LOT, depending on the type of flight you are designing for. Look at sailplanes vs jets. And no, it's not just slow vs fast....
Since you are posting in the Beginner column, best advice - STEAL. Look for a plane that is pretty close to what you want yours to look like. Best if you can find a picture looking down from the top. From a printout, or even on your monitor, measure the wingspan, then measure the width ("chord" in aerodynamic terms). Let's say you get a 5" span, and 1" width. That aspect ratio is 5:1
If you got oddball numbers, like a span of 6.75 and a chord of 1 3/8, divide both numbers by the width to get the right side of the ratio down to "1". 6.75/1.375 = 4.9 and 1.375/1.375 = 1, so pretty close to 5:1
For your design, if you want your wingspan to be 50", divide that by the "5" in the 5:1 ratio. Width would then be 10". Don't worry about being all that precise.
Get this book, as an introduction to aircraft design, if you want to know more about the whys. One of the best intros to design ever published:
The following users liked this post:
bhorton (03-22-2020)
04-03-2020, 03:54 AM
#3
About the curves out of foam boards, I do not know if you are refering to the wings or the fuselage and if you are refering to bend foam board or to hot-wire cut it.
So, normally wings are made out of a block of foam, were you put one wing profile cut out of plywood or cardboard for ex, and the use nickel chrome wire to cut it.
If you intend to bend foam planks, 2 or 3 mm thick, you can use a heat gun, carefully, with just enough heat not to damage the foam. it will take time and patience.
both these techniques can be used on any airplane part.
Fly safe, be safe.
So, normally wings are made out of a block of foam, were you put one wing profile cut out of plywood or cardboard for ex, and the use nickel chrome wire to cut it.
If you intend to bend foam planks, 2 or 3 mm thick, you can use a heat gun, carefully, with just enough heat not to damage the foam. it will take time and patience.
both these techniques can be used on any airplane part.
Fly safe, be safe.
