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So I just got some UV curable polymer from bucktown polymer and have been playing with it. First of all, this stuff is fantastically cheap compared to anywhere else. As in, $50 a quart, as opposed to $2000 a quart one paid just last year. high resolution 3d printing is now within range of the hobbyist.

UV curable polymer is a liquid, that when you shine the right frequency of light onto it it turns into a solid. You can make incredibly details 3d models by using a standard projector to project a pattern of light onto it in layers.

Some initial impressions, I got the PS102-UV polymer that solidifies under 385nm UV light. 385nm is just out of range of what indoor lighting usually puts out, but sunlight still has a component in it. I was mainly curious whether it could be cured by slightly longer wavelengths, mainly because 405nm lasers are dirt cheap, as in $10 laser pointer cheap. 385nm LED lights exist, but not lasers. I experimented and the 405nm laser cures the polymer quite nicely! This means I can probably just strap a laser pointer onto my reprap 3d printer and start producing basic prints right away!

I have a high powered 385nm LED as well I was going to try to hack into a pico projector at some point. So far, it is pretty neat stuff.

One word of warning. This stuff stinks. as in, I got the PS102 which is the "low VOC version" that is supposed to stink less, and it is almost overpowering. I can't imagine what the PS100 smells like. I'm going to leave some samples cured and non-cured out overnight and see if the smell goes away.
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12 comments
 
how are you going to spread even layers and how would you support a bigger layer on top of a smaller layer (i.e. how would you build an inverted pyramid).
 
The reprap version will likely be a hack where I hand-spread each layer.

In a real device, you print from the bottom, your container is just a tub of the polymer with a clear bottom, you project a layer then pull up, project a layer, then pull up. You can print an arbitrarily tall object out of a small shallow tub.

here is an example, but there are lots of homemade ones out there, extremely simple design. the fact that there is now an open source of the polymer is game changing

Junior Veloso's DIY High-Res 3D printer
 
that's pretty sweet. I don't really get how the initial attachment to the moving platform happens and how he just broke it off so easily at the end of the video
 
You just experiment with materials til you find one that it doesn't stick to for the bottom window and one that it sort of sticks to for the platform. :)
 
dude the quality of the prints from that printer is phenomenal... too bad it's $4k
 
You can build a comparable for for $200 or so. http://www.thingiverse.com/thing:19185

lots of other designs online. It's actually a very easy build, I got an old projector for $19 on craigslist. gonna see if I can use a UV LED rather than an unfiltered halogen bulb. Another option is to pull apart an LCD panel and just use it directly and a bright blacklight underneath.
 
I'd like something like the solid doodle that can do the plastic extrusion but that I could also attach a CNC head on it and mill something out of a block of aluminium
 
They actually require fairly different machines. a CNC has to apply pressure via the head, so has to be very overbuilt, as the entire apparatus has to withand the pressure of cutting without deforming. they tend to be wide and flat, a 3d printer needs precision but not strength, and tends to be a tall squarish build area. You could make a machine that does both, but it would likely be master of neither.

people definite do it though and mount dremel tools on their repraps and print heads on their cnc machines.
 
You make a good point. All combo devices suck at all things they do.
 
Amazing. I see they have four colors. How would you print in color? I guess cycle the same object through four baths?
 
I am not sure.. I thought it might be so you can pre-mix an arbitrary color for your part. But there are commercial DLP printers that do full color, so someone has figured it out.

maybe a prepass with an inkjet like system? it would lay down the next layer of polymer with appropriate color then do the DLP exposure, the inkjet need not be that accurate as the color resolution need not be nearly as high as the build/dlp resolution/accuracy. You would end up with a lot of extra grey/brown polymer, but if you are buying a 150k machine and paying hundreds per print in your industrial design plant, that may be an acceptable loss. you could re-use it for parts that don't need exact color. definitely a more complicated home hack though, but certainly within the range of possible.
Danny C
 
Hi John, I just found this post while browsing for UV curable polymers.  How far are you on your 3D printing project?
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