Microtruss - Possible To Print?

Hey guys. I’m hoping to make my own metallic microlattices, but I don’t own an SLA printer. Do you guys think a structure like this is possible to print with a Form1, and if so would anyone here be willing to print and sell me one? I will provide the .stl file. Comment or contact me: trejpet@ live. com

Basically, as I understand it, these are made by using 4 collimated beams of UV light in a square configuration that are passed through a quartz mask, and as the resin polymerizes at the interface it progressively conducts the UV light along the same axis to form trusses, aka self-propagating waveguide formation. I suspect they use this method just to decrease total manufacturing time down to a minute, and I don’t see why it couldn’t also be done with normal SLA methods. But again, I don’t own an STA printer and have no real experience with them.

I am no expert in micro-lattices, but from what I think I understand from your description a Form 1 would not be able to do this without some hardware customization. It uses a single laser beam controlled by two galvo mounted mirrors. From what you are saying, it sounds like you need 4 simultaneous and sustained beams. Also the beam is essentially firing up through the resin in an extended cone formation from a single point, so you could never have true parallel beams running through the resin even if you first shot the beam at one location and then another.

That being said, you might already know all that and simply be asking if a Form 1 could likely approximate this structure. The answer to that question is likely yes. However, I do not think it would be as optically strait as what you have the trusses there. It would be printed in the layer method all Form 1 printers use (with down to 25 micron thickness) It would still be pretty strait and likely functional. You seem to have enough support to the tiny structures that the resin might just support itself with good stability during the print. Send me the .stl files and I’ll take a closer look. It really comes down to if those structures will remain stable during the peel process.

Yes I’m aware the method they use isn’t possible with normal SLA printers. But I’m not sure if the method is essential to making them or if it can still be done on SLA.

I tried uploading the .stls here but they were too big, so I put them on my thingiverse account: http://www.thingiverse.com/thing:694163

Second file uses metric units.

I love this project! Read about it back when I was working on aerogels.

I took a look at your file, right now it appears that the micro-struts (particularly the edge ones, which are half-width) appear to be at the limit of our threshold for minimum feature size. It would be fun to take a shot at this, can you redesign the file and make the edge struts full diameter?

I think that’s just an unfortunate truncation of the pattern. If you slice the STL apart at the beginning of the next cell, and discard the first one, it should be fine.

Edit: BTW, this particular structure is “limited” by the original method used to produce them (i.e. self-propagating waveguides). There’s no reason why more complicated structure couldn’t be done when switching to an SLA process - e.g. circular or arc-shaped cells (which should increase the rigidity somewhat).

The struts should all be the same diameter (.00375" I think).

This probably doesn’t need to be printed at 1:1 scale. I just made it as small as I thought the Form1 would be capable of so the finished metal lattice would be the most compressible.

They are, but one side got truncated in half:

Like i’ve said, easily resolved by re-truncating at the start of the next cell including the whole strut.

I see that now when using Thingiview but I don’t see it in the .dwg files. I think it’s just a glitch in Thingiview itself because I’m not seeing the same error in autocad or in my Afinia 3d printing software. I uploaded the metric drawings (as 2010 .dxf and 2012 .dwg) if anyone wants to take a look at them. I also added spheres to all the exposed nodes near the edges in the newest .stl file (10mb)