How to design?

What tools do plane designers use to design their planes? I am guessing CAD, but are there other tools, such as wood-cutting etc? The reason I ask is
that I am interested in designing a 3d plane.
Joel
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thorough knowlege of the way planes fly, and of aerodynamics, physics, and stresses. CAD is not a design trool in of itself. It only enables more accurate, quicker drawings to be made by someone who has drafting/design skill. Dr.1 Driver "There's a Hun in the sun!"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@earthlink.net says...

CAD, unless you are very familiar with using it, will slow you down. When I started making my own, I shamelessly stole a design that was close to what I wanted and modified it. All you have to do is keep the proportions in balance with each other. The key points you should look for are surface areas (wings and stabs), moments (distance of tail feathers from wing, etc.), thrust and incidence lines, and weight distribution. Just about everything else is fair game. If you add lateral area in front of the CG, add rudder or vertical stab area in the back. Shortening the rear fuse means bigger tail surfaces. Mostly common sense stuff.
I would highly recommend starting with something other than a 3D plane for a first try. There have been many designs for these that have come and gone recently, because a lot of people turned out really crappy stuff that wasn't really 3D after all was said and flown. The flow over the fuse, and how that swirling prop stream is going to interact with the fuse and control surfaces, isn't something you are going to hit on on the first try. These planes also need high strength to weight ratios.
I'm not trying to discourage you, but I don't think you are going to be happy with anything you do from scratch until a few planes in. What size did you have in mind? What types have you flown already, and what are you trying to make this one look like/perform like? Anything special in the way you want it to look or do? Post back with some of your design criteria and maybe we can point you in a direction with a good chance of success. As far as tools go, a bandsaw or a scroll saw is wonderful thing to have for all those ribs. Pin em together in a stack and churn out all of em at once. A dremel is also very handy.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
says...

CAD,
I was envisioning a really light, backyard type of plane that could do 3d with a GWS Pico-type power system.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Inspiration can be had at <http://www.flyelectric.ukgateway.net/indoor.htm .
-tih
--
Tom Ivar Helbekkmo, Senior System Administrator, EUnet Norway
www.eunet.no T: +47-22092958 M: +47-93013940 F: +47-22092901
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Go for it.
If your first version doesn't work, tweak it and try again.
I haven't done my own design yet, but I've been collecting pictures and information on the planes that catch my eye (pattern planes, Edge 540, Doghouse, some sticks). I've purchased some plan sets. I've built one plane from plans and have started another.
I've got the following tools to work with for production:
    table saw (2)     band saw (metal-cutting blade)     jig saw (various blades)     belt sander (6")     foam-cutting stuff     vacuum bag system
When and if I ever draw my own plans, I'll probably rely mostly on hand-drawn stuff. I don't have a printer or plotter on which I can do my own plan sets, and I don't relish taping 8.5 x 11" pages together.
RCM and RCR have both had articles on how to design and build your own planes. I read them avidly. I think I even bought--yes, I did buy!--two books on design/building. Make that three, counting the one on how to build from plans.
My opinion, for which I won't kill or die, is that if That Looks About Right (TLAR), it'll fly about right. I've built and flown a lot of crooked planes, and all of themhave been fun, so I'm not too worried about the outcome. My latest goofball plane is a 1.20 size hand-me-down on which I've put a 2.15 MVVS gasoline engine (thanks, Ed!) to break it in.
Experiment. Have fun. Let us know how your plane(s) turn out. Let better pilots fly your designs and listen to what they tell you about them. Learn from your mistakes. Avoid lists of advice like this and do what you think is right. :o)
                Marty                 <http://www.moleski.net
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Pencil, paper, compasses, ruler, eraser, slide rule, curve templates, knowledge of the many materials and aerodynamic laws and by-laws of planes. for drawing, a CAD program can also be used, though it will not replace craftmanship.
--
Rgds,
P
From Arcen, South-East in the Netherlands
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.