Printing out .pdf plans to scale

I use tile printing and find setting up the printer for it is quick and easy. I print with the marks so that I can line up the pages but it is a long job sticking them all together.

This is a plan that Duke sent me. The largest I have printed off - 25 sheets of A4.



It took me over an hour to tape that together!

I have found that some pdf files will not print accurately. Not many, two out of about 20 that I have printed. I don't why - I follow the same routine and that is a little frustrating and a waste of paper.

I also take the pdfs and convert them to dwg/dwf files. I then extract parts and use packages from "Devcad"

http://www.devcad.com/eng/default.asp

so that I can machine out ribs and formers. It also lets me modify parts and shapes to suit me. I can add tabs to ribs to simplify jigging, lighten ribs and because of the CNC router - cut plywood with ease.

This is the wing with half ribs following standard build and a little lightening from a Skyray 35 plan. (I have posted this before)
 

 
This is the same wing with identical profile. Sheeting and capping strips have been applied.
 


This is the CNC router in action.



I have built several models using this but not yet a Skyray 35. I swapped three sets of ribs for an LA15.

I use Print2Cad software to convert the pdf files but sometimes the resulting drawing has to be "touched up" to provide continuous cutting lines and smooth out wobbly bits of lines.

Modification is simple - I haven't cut this one yet.



Long story but I have found that the pdf file is only as good as the original plan used for scanniing. With all software there are anomolies

As I have mentioned - I have a couple of pdf files that I cannot print accurately (let alone scale!)