There are a number of ways to translate from plan to wood parts. I am not a fan of tracing, mainly because I've not mastered the technique. I've tried using carbon paper between the wood and plan and tracing through that way, but aligning the parts on the wood when you can't see where you are putting them caused me to abandon this method.
I then went to making a copy and cutting up the copy to glue down. A couple problems can come up using this method as sometimes the master will skew or slip going through the big coppiers and the result can be that parts of the copy are distorted. You usually find this out when the part doesn't fit well. One other issue was which side of the line do you cut to? A lot of the drawings use very wide lines at times and it is easy to stray from one side of the line to the other when cutting. After sanding things smooth, you end up with an undersized part.
My method now is to use a CAD program, I use Rhino 3d, and copy a portion of the plan to a JPG file. I the use that file as walpaper on a blank drawing and use points along the edge of the line to define a curve which is the outline of the part. Rhino allows me to smooth or fair the lines to remove any misplacements of the dots and get a nice smooth outline. I then scale this drawing to the exact size needed. Now I have a part I can print, or even better yet use a tiles to layout a full sheet of wood. Once I have the parts positioned on the wood, I can the print out the drawing and glue it to a sheet of wood for cutting. The line printed in this manner is razor thin. I cut on the band saw and make sure to leave a bit of stock outside the line. I then use the disk sander and sand exactly to the line. My first time using this method hooked me for life. A stack of ribs cut in this manor, when stacked together look as if they were laser cut. There was no final sanding to get them all to the same shape.
I now use a variation of this to make copies of parts from a kit. Here I make a copy from the punchout scrap. IE for the 4*60, being laser cut, they make a very good source for reproducing parts for crash repair. I aquired a 4*60 a while back that someone had started building the wing and run into problems and abandoned the kit. They had glued the two wing halfs together with a major twist and had poorly glassed them together. I skinned the glass off using a heat gun and then sawed the wing in half at the joint. In the process of doing this, I destroyed the two root ribs. I use the scrap wood for those ribs and my Cad method and reproduced those ribs. The finished ribs were an exact match for the destroyed ones.
The first photo is of the scanned 4*60 W1 Rib for use as the wallpaper
The second is of the rib read to be scaled to size
The third is of a set of quicke 500 ribs layed on a 3x36" sheet
The last is a portion of the print out of that sheet for gluing to the balsa for cutting. My printer will print banners and I use a roll feed that allows me to print the full 36" length. I try to lay out two sheets of balsa at a time to save paper (the roll stuff is expensive)
Just one more way to go from plans to wood. The great thing about this is it is now an easy job to scale up or down. Just change the size in the drawings are change the cutouts for spars and such to stock size and away you go.
By the way, there was a linke posted recently on another subject for a free CAD program. I haven't tried it but reports I've seen on other machinest sites are favorable.
Added***
This is the links from the other forum.. Like I said, I have not used it so you are on you own here.
free manual here:
http://www.al-ki.com/tcad/download.php
or here:
ftp://ftp.imsisoft.com/download/turb...deToTurboCADv4.
pdf
free TurboCAD here:
www.freecad.com/files/TCAD_LE_setup_files.exe