Well, after my first attempt at a mechanical iris yesterday, i wanted to make another one this time with a complete open back plate.
So i review my drawings, and i change the size of the leaves, so the track pins travel in a path always within the back plate.
and here´s the result of todays build!

Bueno amigos, después de fabricar mi primer iris mecánico ayer, quede con ganas de hacer un segundo iris, pero esta véz, con el fondo abierto completamente. Revisé mis dibujos, y cambié el tamaño de las hojas, para que los pines que corren en las ranuras, viajaran en una trayectoria que estuviese siempre dentro del anillo trasero, y aquí está el resultado.

Este es mucho mejor que el primero, lejos. Me sugiere que yo podr&iacute;a hacer un plato autocentrante para mi torno.<br> <br> <strong>This is much better than the first, far. It suggests to me that I could make a self-centering front plate for my lathe.</strong><br>
Muchas gracias, y no es mala idea lo del plato autocentrante para el torno, ojal&aacute; incursiones en ello, ser&iacute;a un proyecto interesante.<br><br>Saludos!
Wow, very cool!
Thanks man!
Yep! Are you going to make a step by step instructable for this? <br><br>And just wondering, do you use a translator or do you know both spanish and english?
well, i have enough pictures to make a step by step, so now that you mention it, i will make a step by step.<br><br>And abouth the language, i do know both, im from Chile, in South America, so im a spanish speaker, but i know some english too.<br><br>Regards!
Ah, good luck with the intrsuctable!
Very cool, how do you figure out how many leaves/what size they are? I assume those two things depend on eachother, but is there a calculation you use based on the overall size and how many leaves or something?<br>I am going to try one right now out of foam core and cardboard as an experiment.
Ohgh &not;&not;, too small pic, here it is at full size.<br><br>http://www.flickr.com/photos/rodrigo_mr/6044550664/sizes/l/in/photostream/
That helped me see how it works. I can't find anything about how to figure out the measurements besides trial and error.<br> I did find some pictures that show a different design where the pivot pin and guide pin are on the same side of the leaf.<br> I think I am going to try that so I don't have to figure out the exact size of the leaves. Here's a pic of what I mean:<br> <a href="http://t3.gstatic.com/images?q=tbn:ANd9GcQh9jlo5fynuqQvnkuxgdJn1Fg-UgDzNAB0W6Z75SZhOoEvnkcP">http://t3.gstatic.com/images?q=tbn:ANd9GcQh9jlo5fynuqQvnkuxgdJn1Fg-UgDzNAB0W6Z75SZhOoEvnkcP</a>
Here you can see a drawing.<br><br>The main ring is in green. Then, in the right picture, theres a leaf too short (in yellow), you can see the pivot point, up, at 12 o'clock, the other yellow circle, represents where the track pin goes. in this drawing, you can see the leaves, in the initial pisition, when the iris is complete open, and the final position, when the iris is closed. The arc that connects, the two positions of the track pin, is the path the track will follow during the operation of the mechanism.<br><br>The picture in the right, shows a path (yellow arc) that eventually will go out of the ring, as the iris closes (that&acute;s what happened to me in my first iris), while the picture in the left, showss a path (red arc) tha is allway inside the ring body.<br><br>i hope this helps!
Hi, i first made a draw, i use autocad, but you can use just paper, pencil, some compass, and angle metter, but autocad or any technical drawing software is much more easy.<br><br>So i first figure out how big the rings are going to be, in this case the size of the rings was determined by the holesaws i had, so based on the hole saws sizes i draw two concentric circles.<br><br>Then, the number of leaves is just how many leaves you want to use, in my case i use 8, but 6 would work well too. 10 or 12 would work too, but when the iris closes, the leaves tend to overlap and twist, and the more leaves you have the more difficult is to close the iris. I guess, if you want to use more leaves, you have to use a thinner sheet metal, or any material you want to use for the leaves.<br><br>then the shape of the leaves is just a fraction of the ring, (the space betwen the two concentric circles) and the size of the leaves, is determined by the path the track pins will travel through. In my first Iris, i do not notice this, so i made the leaves too short, and the path the track pin had to follow, was, in some point out of the rins, so i had to make a complete back plate with track, instead of a ring.<br>So you have to choose a leaf lenght tath allows the track pin, travell within the back ring. Is much more complicated to write it, than do it XD.<br>I will show you some pic of my drawings, and everything will be very clear!<br>