That is great info, using a cad program is the fastest way of scaling.
With autocad you can make the drawing 1:1 then scale it to the size that you want. Plot to a pdf, email it to whomever you wish. They can then take the file to your local printer and have it plotted.
Here is one that I have been working on. 1/16 scale Bridge master ext.
You can also search the web for free cad software there are many different cad programs available. Learning the software you get has a large learning curve.
Sketching things out first always helps.
Here is just one of many,
http://www.cadstd.com/
good luck, and if you have questions just ask.
Carl