Need template for way covers - Bellows Origami?

[PEU]

I cant find a decent way cover here for my router table, so Im trying to do them myself.

I need a template for folding paper or plastic to form this:



Any hints welcome, Im still searching google, but no luck yet


Thanks


Pablo

[chuckknigh]

I folded a few bellows a while back -- straight ones are simple. All you do is take a rectangle of paper (or leather, rubber, or whatever) sufficient to make the box section. Remember it has 8 sides...not 4.

Then start drawing lines, and 45 degree diagonals between the large sides. That's the trick. Then just alternately fold each pleat, and use the diagonals to connect them. Simple, once you've laid out the pattern.

Check the photography sites. I learned to do it by reading a photography magazine a LONG time ago, either Shutterbug or Popular Photography. It was a sub-article in a "build your own view camera" article.

-- Chuck Knight

[chuckknigh]

http://www.mottweilerstudio.com/downloads/bellows.zip
http://www.cyberbeach.net/~dbardell/bellows.html
http://www.rhoadescameras.com/Camera...ws/bellows.htm

These 3 turned up on a quick google search. I'm sure there are others. You won't need to worry about the bellows spacers or the light-tight aspect of the construction. Just focus on the folding -- it's pretty simple, once you figure it out. Kinda' like CNC!

This advice comes from personal experience...start by folding up a sheet of copier paper. It's cheap, very accurate, and makes a nicely sized bellows for our purposes.

- Chuck Knight

[chuckknigh]

http://www.groeg.de/puzzles/rocket.html

Here's another one. Complete with pattern. Just add a 4th side (identical to side 2) and you'll have an enclosed bellows. This one is admittedly small, but easy to extend.

-- Chuck Knight

[PEU]

Hey Chuck, that was fast THANKS, after I posted I kept looking and found a PDF with a bellows theorem, but your sites are more straightforward.

Im doing a template in coreldraw, if someone wants it, I can post it, before trying of course!


Pablo

[greybeard]

I think I 'll put off finishing the cnc till I've made the rocket

[chuckknigh]

Looks fun, doesn't it? :-)

Bellows are terifically useful, regardless of the specific application!

-- Chuck Knight

P.S. If your finished bellows doesn't collapse far enough, try making a tapered bellows. It'll collapse to a much smaller area, since the folds don't overlap. Slightly harder to lay out, though.

[PEU]

I just made my 1st prototype:




It came out pretty well I used a 150degree angle thats why it came out wider on the top.

Attached is the template.


Pablo

[PEU]

And here is the bellows model that will go into my machine:



These bellows are curiously strong (like altoids )



Attached is the template.


Tomorrow I will purchase some plastic sheet to make them permanent.


Pablo

[PEU]

Forgot to ask:

What kind of sheet you think will be the best?

it must resist back and forth movements without breaking.

Thanks


Pablo

[greybeard]

This may be a bit of a mis-direction, but as a fanmaker, I would use fine cotton sheeting (!)
Stretched over a frame and then painted with shellac(french polish) you'd get a pretty tough copy of the original camera bellows(black if you used black dye/shellac) or pink stripes if you buy the wrong kind of sheets.

[chuckknigh]

Told 'ya they were easy to make. Simple, really.

Standard materials for bellows are leather and certain rubbery fabrics. Usually these are too soft to self-support, so they end up sloppy -- the "stiffeners" you saw on the camera-making web site are the standard approach to making the bellows self-supporting.

Of course, the standard materials also address the requirements of light and air tightness when making cameras and concertinas.

I might play around with some papers, or maybe tyvek? If your machine is being used for metal, then the chips may be hot -- consider that in your design. Otherwise, paper holds up amazingly well in a bellows configuration. Cameras don't usually go through a lot of flexing cycles, though, compared to something like a CNC router.

-- Chuck Knight