Variable aperture nozzle hot end for improved printing speeds

Has anyone experimented with using an iris-type mechanism to create a variable nozzle aperture?

For example, Thorlabs sells stainless steel apertures with a 0.8mm - 12mm range.

[www.thorlabs.com]

A slicer could identify an ideal opening size/flow rate for a given path and actuate a servo that connects to the iris via a Traxxis-type post, greatly improving printing speed while (with a more ideal iris) maintaining resolution. If the iris closes completely, stringing could potentially be eliminated. Larger format printers might also begin to make more sense?

Regards,
Jason Fisher

Maybe a variable rocket/jet nozzle would be more appropriate.

I think this idea (variable nozzle size) is amazing. The implementation is going to be fun.

I am a big fan of simple. Here is a mockup that would allow for accelerated printing. You would need 4DOF so you can print big wide strips in any direction. The print head orientation could be done completely in firmware to make slicing easier. However, you will need to revamp slicer to allow for variable width printing.


Edited 2 time(s). Last edit at 08/27/2013 02:44PM by nicholas.seward.

The iris doesn't have a tip. I guess it will be difficult to print with.

IMHO a dual head extruder with two different nozzle sizes will do the job much better.

---

Detlef

Excalibur Hotend

reprapclean32.png

reprapzone.blogspot.de

I have been thinking of something along the lines of overlapping washers. When aligned, the washer opening is maximum size, or pull them apart to reduce the nozzle size.

Or two fixed washers next to each other, with a third washer stacked on top that moves up/down to adjust the nozzle, using the space between for the nozzle output. Like a Venn diagram, sans overlap for maximum size and overlapping to reduce the geometry. This has the advantage of maintaining a relatively constant shape across all sizes.

If we had 4DOF, it would be nice to do away with cylindrical nozzle output completely. I feel like we would have better adhesion and sealing with a wider/flatter stroke.

A variable jet nozzle-type design might be superior to a flat iris, but then you might have the problem of compressing the material as you reduced the geometry.

[maks.sukhoi.ru]

An idealistic design might be something like a metallic flower.

[www.beadinpath.com]

I really like this iris business card design for its simplicity:
[www.thingiverse.com] - [www.youtube.com]

Neat animation of the internal operation of an iris:
[www.pierretoscani.com]

Good visualization of more robust iris design mechanics, but it is not constant shape in its current form:
[www.youtube.com]

You might be able to build some kind of pitch into a design like this? I like the simplicity:
[www.youtube.com]

Plastic spaghetti portioning iris:
[www.surlatable.com]

Nanomedicine iris design for dynamically filtering different sized nano-sized compounds:
[www.foresight.org]

MDF and sheet metal iris:
[www.youtube.com]

Iris diaphragm design thread - [www.instructables.com]
"Rugged" iris design? - [www.techbriefs.com]

Another DIY iris build:
[www.youtube.com] - for this design: [www.audiogroupforum.com]

All of that said .. you are right about keeping it simple, and maybe the better approach is a sliding door. The trade-off, though, would be between the complexity of a constant shape iris vs adding an additional DOF to a design. The Simpson may lend itself better to the additional DOF?

Edited 7 time(s). Last edit at 08/27/2013 06:28PM by jason.fisher.

Delta robots can have up to 6 DOF's.
[en.wikipedia.org]