How to fold long pieces without bending

[hornswoggler]

To avoid twisting, it is important to bend the part across the whole length of the part evenly. As you all know, the longer and thinner the part this becomes impossible to do using your fingers.
A bending jig may be the solution. Get two sturdy pieces of thick cardboard, the kind that is used for the backing of wall calendars. (One piece cut in half works too.) Now butt the two pieces up against each other with the two longest edges and connect them with clear sticky tape so that you end up with cardboard that has a hinge.
Now rough cut your part (leave waste material on both sides of the fold you want and score it.
Align the score with the hinge of your bending jig.
Align the edge of a sturdy metal ruler on top of your part. So. it s also aligned with the hinge.
Hold down the ruler with one hand to clamp the partin place.
With the other hand lift the still movable flap of the jig up. Voila the part gets an even bend!
With the crease established you can now cut the excess off the part.
Good Luck!

[airdave]

So, who is going to design (and sell) the "patented paper modellers Paper Bending Brake"?

[airdave]

Originally Posted by Don Boose

Don't cut the part completely out before scoring and folding. Leave plenty of paper on both sides of the fold line. The more paper there is on either side of the fold line, the easier it is to get a clean fold. After you have folded the part, then cut away the excess.

Don

In this case, there isnt a lot of room or excess paper around the part,
but there is enough paper space along the length of the rail part,
to do what Don has suggested.
If nothing else, it makes the thinner (4mm) outer edge faces a little easier to score and fold.

[hornswoggler]

To avoid twisting, it is important to bend the part across the whole length of the fold evenly. As you all know, the longer and thinner the part this becomes impossible to do using your fingers.
A bending jig may be the solution.
1. Make the jig: Get two sturdy pieces of thick cardboard, the kind that is used for the backing of wall calendars. (One piece cut in half works too.) Now butt the two pieces up against each other with the two longest edges and connect them with clear sticky tape so that you end up with a piece of cardboard that has a hinge.
2. Prep the part: Score the part before cutting it out. Now cut out the part. If it is narrow, leave waste material on both sides of the fold.
3. Bending: Align the score of the part with the hinge of your bending jig.
Place a sturdy (inflexible) metal ruler on top of your part aligning the edge with the score . The goal is to have hinge, score and ruler edge all aligned on top of each other.
Hold down the ruler with one hand to clamp the part in place.
With the other hand lift the still movable flap of the jig up. Voila the part gets an even bend!
With the crease established you can now trim off the excess off the part.

The description above generates a valley fold. For a mountain fold use a needle to poke holes at beginning and end of the score. Then flip the part over and use the pin pricks for alignment.
Good Luck!

[AP40rocktruck]

Weather it is long bends or short bends, a device similar to the ones used for photo-etched parts will work just as well.

One could make a simple unit from some brass, which I prefer over aluminum. a flat surface and a parallel clamp to hold the paper taunt along the intended fold line. Then a loose equivalent length of thinner brass (.015") 0.4 mm thick sheet slid under the section to be folded. Lift with even pressure and begin the fold.

There are mini-breaks sold by Micro-Mark, but they seem to clunky in appearance for paper.

More thought & maybe a little fabricating........

AP40