Prints for building airplanes? (Full Version)

All Forums >> [RC Airplanes] >> Scratch Building, Aircraft Design, 3D/CAD



Message

DuceNova -> Prints for building airplanes? (5/14/2008 4:23:37 PM)

I have AutoCAD LT on my computer. I need prints for airplanes that I can import then print out.

Also, how do you draw the curve in the ribs?

Thanks,

John



draftman1 -> RE: Prints for building airplanes? (5/14/2008 5:43:56 PM)

how much do you know about autocad? basicly you can use the arc tool or use the eclips tool and trim it. some frre plans are dwg or dxf file, those can usually be opend up with autocad. if they are pdf then you need a pdf converter or if you have a newer copy of autocad then it mite have it built in



mmattockx -> RE: Prints for building airplanes? (5/14/2008 5:52:53 PM)

John,

Look in the Scratchbuilding Forum, there is a sticky thread at the top with a long list of sources for plans and designs.

For ribs, it depends on how your airfoil shape is defined. If you are ballparking one by eye (which works fine for almost any model), then you can use arcs or ellipses combined with straight lines. If you are using airfoil data from NACA or similar info, then you plot the coordinates using a polyline and then SPLINE it to smooth the corners. I always draw all my airfoils with a 10" chord in my source file and then it is easy to scale them to any chord as a simple multiple of 10. It's really critical because CAD will scale anything to anything, it is just an easy thing to remember when pulling in a block to a new drawing.


Mark



Mike Emilio -> RE: Prints for building airplanes? (5/14/2008 11:43:39 PM)

quote:

ORIGINAL: DuceNova

I have AutoCAD LT on my computer. I need prints for airplanes that I can import then print out.

Also, how do you draw the curve in the ribs?

Thanks,

John

If you don't have a large format plotter, you might be just as far ahead to get something as a tiled pdf. You might wing up with 20-30 sheets, but at least you'll get something printed out. Any new decent wide format plotter will set you back a few thousand bucks.



DuceNova -> RE: Prints for building airplanes? (5/15/2008 2:14:47 AM)

Thanks to all for the input. I have a friend that plots out big prints for me. I should know how to do elipses, splines, and arch, BUT it's been a while since I've had to do them. Time to wind the brain back up and get back into the game! LOL!

I did download a couple of DXF files and worked with them a little last night.

Yes, it takes about 8 sheets of paper in landscape (to be wide enough) to print out a 48" wing on the HP5610 printer. I call it "killing trees".



longdan -> RE: Prints for building airplanes? (5/20/2008 9:02:44 PM)

For doing foils, download Profili2. It has a huge library of foils in its database. They can be exported as DXF files which can be opened in autocad. Profili2 asks you what chord length you want. If you register it, it opens up a whole lot of options like spar cutouts, lightening holes etc. But these can be done in autocad as well.



dreadnaut -> RE: Prints for building airplanes? (5/20/2008 11:02:48 PM)

quote:

ORIGINAL: mmattockx

John,

Look in the Scratchbuilding Forum, there is a sticky thread at the top with a long list of sources for plans and designs.

For ribs, it depends on how your airfoil shape is defined. If you are ballparking one by eye (which works fine for almost any model), then you can use arcs or ellipses combined with straight lines. If you are using airfoil data from NACA or similar info, then you plot the coordinates using a polyline and then SPLINE it to smooth the corners. I always draw all my airfoils with a 10" chord in my source file and then it is easy to scale them to any chord as a simple multiple of 10. It's really critical because CAD will scale anything to anything, it is just an easy thing to remember when pulling in a block to a new drawing.


Mark


I avoid using splines. They are not really necessary for this kind of work, and become difficult to work with if you intend to use a laser cutter. Laser cutting works better if it is a ployline with only straight line segments. If not, many laser cutters will charge extra to get to into this form.

For drawing airfoils, I use a data file that lists points. I use a script file to draw the points in ACAD (this might not work in LT). Then I trace them with a pline.

The script file is just a text file, where tou change the file extension to.scr, and contains the follwing

Pline
1.1,1
1.2,2
1.3,3

at the command line type "script" then enter. you will be prompted to enter the name of the script file, enter the one you made.

The first word -pline- is entered into the command line. the hard return after Pline in the script file is read as "enter" by the command line. find a data set of the airfoil you want and try this. You may have to insert some blank lines in the .scr file because some command inputs require you to enter twice.

I agree withs johns technique of drawing the airfoil to a size that can be easily scaled. I use 1 instead of 10, but either will work.



Page: [1]

Valid CSS!




SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.
0.140625