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

Similar Threads:

• looking for some laser-origami experience...
• G0704 bellows
• Protection Bellows - HEMA
• Rubber Bellows
• Bellows / Boots

[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

[Rance]

[ All you do is take a rectangle of paper... ]

Whenever someone begins telling me something and prefaces it with something like "Alls you gotta do is...", then I get REEEEEEEALY cautious.

The problem with your advice here Chuck is that you use too many words and phrases like "easy", "simple", "That's the trick", "Then just...". And "it's pretty simple, once you figure it out.". Well doooooh, most ANYTHING is simple once you figure it out.

[ Kinda' like CNC! ]

That reminds me. "A brick flies, kinda like a helicopter doesn't".

I'm just having fun with you Chuck. I sure hope you have a sense of humor. Seriously, this is great. I always wondered how to do this, now I'm gonna try it for myself. And I'm gonna MAKE my kids build one too (for their own good of course). Thanks for the enlightenment Chuck. And thanks PEU for bringing it up.

Rance

Edit: PS: See also http://cnczone.com/forums/showthread.php?t=10754
and
http://www.cnczone.com/forums/showthread.php?t=5392

[chuckknigh]

Hey, when it actually *is* easy, then it's just fun! And, it *is* simple once you figure it out -- but having a pattern makes a LOT of difference for some people.

No problems with your message, Rance. No problem at all.

-- Chuck Knight

[RotarySMP]

I made bellows for a 4x5" camera from thin soft kangaroo leather. The leather was really floppy, but I gently beat the folds in with a wooden mallet, and the bellows became quite rigid (without any stiffeners.)

[JavaDog]

Whenever someone begins telling me something and prefaces it with something like "Alls you gotta do is...", then I get REEEEEEEALY cautious.

A bit OT, but that was my nickname when I was a kid. I would come up with some crazy idea/scheme, and when I was told it wouldn't work/was too complex, my response always was: "No, all you gotta do is...".

These folded paper bellows are pretty neat. I may have to make a set for my Y-Axis and Z-Axis when I get my machine done...

Can't wait to see the final result!

[Bloy2004]

Don't forget to post pictures of the finished bellows before AND after installation...Please?

I'm interested in how tightly they can be compressed in relation to how far they can be stretched given a particular material.

John (Bloy)

[chuckknigh]

Since the folds overlap, there is a limit to how tightly they can compress.

To get around this ALL YOU HAVE TO DO is to make a tapered bellows. That way the folds don't build up, and the entire bellows will collapse down tighter for a given length.

:-)

-- Chuck Knight

[PEU]

Today I purchased Shellac flakes, it called "Goma Laca" here, in the local version of ebay for only $7 the kilo. Also purchased some cloth. If I have time I will do the bellows tomorrow, will post pictures of the process if I succeed


Pablo

[greybeard]

Pablo - Find an old glass or polythene jar. Put about 0.5" depth of the flakes in the jar then cover with about 4" of methylated spirits/methanol(?). It takes a long time to dissolve, but you have found the cheapest method !
Give it a good shake as often as you can. It might take a couple of weeks to go into solution, but it will almost certainly leave a solid/jelly residue.
Pour off the brown liquid and use that. Experiment with a small piece of cloth first. It only needs a very dilute solution to stiffen thin cloth enough for it to take a good fold.
Use a big brush, do it in the open air(fumes give headache) and brush out quickly as it dries fast. Leave it for a day to harden before you do any folding, otherwise it might all stick together. Dust it with talc to make it easy to handle.

if you've used white cloth it's easy to see pencil marks for the fold lines.

The closed dimensions will be about 10% more than the number of folds times four times the thickness of the cloth, so choose the finest cloth possible.
(The thickest part are the corners where there is a doubled layer.)
Use cotton or silk. A synthetic like polyester tends to produce floppy folds.

Allow plenty of length. If you stretch the folds out fully flat, it will probably not fold up neatly again. I would allow the folds to only extend to about 75%.
If you make the bellows in sections, I think a thin card "wall" made to the same cross section, and used as a means of joining sections together, will also help to keep the folds under control, and one at each end will make mounting easier.