My way of solving it.

Built using plans by Johan Hansson, downloaded from FliteTest
Johans original build thread is here: Sportskala Viggen EDF
There are plenty of good build logs already made for this awesome model, so I won't go into much detail.
I'm only showing how I got around what, for me, was the more critical steps.

My biggest concern was getting the formers done.
A tip from D_Fast on the SAAB Viggen thread suggested using cardboard.
Mine are made from empty Xerox printer paper boxes, which are about 2mm cardboard.
A well made pizza-box would probably work too.

Made some A3 and A4 size printouts for the formers to help with printing.
A3_Formers_Btb_Ctb
A3_Formers_F2tb_Ftb_Atb_B...
A4_Formers_Dtb_Etb
A4_Formers_G1tb_E2b_G2b
A4_Formers_Htb

I make a rough outline with a dremel and a 2mm diamond wheel point.


Then, with a very light hand, sand down to the lines using a 6,4 mandrel.


Final sanding to get a smooth edge is done with 400 - 600 grit paper.
That is also used to get rid of the "paper-frizz" around the edges.

I make two formers for each station, one for the inner cut, one for the outer.
They are dirt cheap and quick to make, and I like the extra stability.
I make a centerline on each former to aid in placement.


I also extend them about 10mm from the line that marks the dividing line between upper and lower half.
This is to get lead-in and lead-out ramps that helps keeping the entry end exit of the hotwire straight.


A light mist of 3m 77 Scotch Weld on the formers sits for about a minute before I put them on the foam.



Another problem I had, was to cut the foam squarely.
The gravity method didn't work for me, so I made a jig from laminated shelves.
Instant square cuts.


Not too bad for a first attempt. (I hope...)


Measurements for each block:
Width: 180mm.
Height: about 100mm
A-H
824mm

A-B
100mm

B-C
120mm

C-F
305mm

F-H
298mm

C-D
68mm

D-E
74mm

E-F
163mm

F-G
227mm

G-H
71mm

Coming along . If you cut carefully with scissors you barely even need to sand around the edges . At least with posterboard that is . The Square jig is a good idea .

Thanks
Yeah, I tried with posterboard, but I guess the one I found was the thinner kind, and it didn't work well. Too flimsy.

Hi for the viggen plans how do I print all of your plans and piece them together? after I printed them, they were uncompleted and I couldent put them together please help

I just made the ones for the formers, as those were the only only ones I needed for now.
To print those you need to select the right paper (A3 or A4) for your printer and also make sure the orientation is correct (Portrait or Landscape.)
I suggest you use PDF-XChange Viewer. It has an excellent preview function.