OK then, I've had this idea for quit some time, and the arrival of my very first dragon kit and hence my first PE frets had driven me to start this little project of mine.
first, initial idea was taken from here https://archive.kitmaker.net//features/447.
i do not pretend to produce any of the market PE tools, just something to those who use PE here and then and the occasional after market PE.
so, I'll start with materials, and tomorrow i hope to start some work on this.
materials are:
5X30 CM plastic rulers.
1X30CM metal ruler.
3X plastic protractors.
1Xbox of 3/16 screws.
1Xbox of 3/16 dicsc/
1Xbox of 3/16 winged nuts.
1Xbox of epoxy glue
1X 34 CM by 24.5 CM plastic cutting board
1X 19.5 CM by 29 CM plastic cutting board.
total cost: around 21$ (at my place's prices)

first progress: cutting excess parts from rollers. Plastic rollers has some excess bits with no scale marks on them. I have placed the metal roller on the 30 CM and 1CM marks, made a guide line with a knife, and cut it with my dremel. Then, using a sanding paper I have smoothed the edges. using the knife again, i cut the plastic that got stuck during cutting.
Note: use respiration mask - some quite smelly fumes come out, and plastic powder.
sorry for the pictures - the flash just came back from the rollers, so they are a bit dark.
Before:

During cutting:

Done - all of the five rollers:

further progress - and this time: cutting some holes.
i started with installing the correct drill bit to my driller.
then, i have market the hole's places.
then, i put some toilet paper underneath the roller and on top to absorb shocks and protect it from the clutches (?).
note: use your other hand (the one that does not hold the drill) to steady the roller and the drill so it does not break and you drill in a strait line. you should also note, that the drilling was done using a very slow speed with a minor boost here and there.
the drill

drill bit (I don't know exact size, but it fits the screws so it's probably 3/16)

toilet paper:

underneath:

on top:

holes ready!


a trio prepared:


enjoy

another progress made:
the most difficult and tiring phase: chucking away (or sanding) place for the metal roller. the metal roller will be used to fold PE parts that are held under the plastic one.
now, i cant stress this enough in this phase: YOU MUST use protective gear such as respiration mask and goggles! very little bits of plastic will fly in every direction, and some plastic powder so protect yourselves!
first, i continue some work on the plastic roller. i cut three to 24 CM long, in the method described above. then, i place one roller on the large cutting board, mark the holes and drill away. after that, i install the plastic roller with screws, discs and wing nuts, place the metal roller and mark it's borders with a sharp knife. then, using the more coarse sanding bit of my dremel. i have sanded just a bit at start; just to get approximate depth for the metal roller. after that, i have sanded in up and down motion to the entire length of the borders.
Note: this phase is tough, and the outcome is not all that accurate and nice. the metal roller sits "ok" in its place. not tight as i had wanted, but it's ok.
after that, i have cleaned all the plastic that got stuck in the way.

drilling holes in the cutting board:


a snug fit!

marking the metal roller's borders:

metal roller in place:

testing it with academy's merkava MK4 PE set:

Matan I think I understand what you are doing here, however I question the durability of the plastic rulers when it comes to PE bending. I believe you would be better off securing a steel rule or better yet a piece of aluminium with a straight edge.

PE is that tough?

That depends, some PE bends really easily others not so. It is just my belief that the edge of the ruler will become damaged and unable to produce the results you seek fairly quickly. A steel ruler would overcome this problem, but it may be difficult or next to impossible to work with some of the very small PE items due to its inability to grip the small surface area you have to work with.

Well, anyway I have finished couple of days ago, just got lazy with the photos.
I have abandoned the whole protractors idea. In the future perhaps i will add a punch n' kill device for rivets, and perhaps a handle bender. Rollers will be change to metal when the need will come.
This stage, I began with preparing the 'cutting corner'. basically, one roller will hold the PE while another moves on an axis so I can place it to match the part i want to cut.
Use Protective Gear!!!

drilling holes:


matching the rollers:
[imghttp://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs159.snc1/5936_1194574026055_1279560695_561982_20704_n.jpg[/img]
putting epoxy paste on the outer screws (4 total). you can see the axis for the second cutting corner roller. i have placed the roller, marked holes overlapping holes and cut away!

under-photo:

voila!



I do hope that you have enjoyed reading as i have enjoyed building this. All comments, questions etc. are welcomed