Floating resin in Bottom Up setup

Various topics related to Vat design, construction and coatings.
Phife
Posts: 239
Joined: Fri Jan 17, 2014 5:24 pm

Floating resin in Bottom Up setup

Postby Phife » Tue Sep 16, 2014 7:43 pm

Hey guys,

I was thinking the other day, has anyone tried floating resin on a thin layer of water in a bottom up setup? I know its common in top down, but what about in bottom up?

I thought, maybe with the resin floating and the build platform just above the waters surface but in the resin you might do away with any sort of sticking whatsoever. The cured resin would stick only to the build platform and not to the water.

Is anyone willing to try? I cant right now as my printer is being rebuilt. Anyone with a bottom up setup should be able to try it, just mix up some salt water (30% salt to water by weight) add it to your vat, probably a 1/4" (6mm) would be enough and then add the resin on top. Adjust your start Z height to the new resin level and try printing.

I wonder what would happen..

adambx
Posts: 119
Joined: Wed Apr 09, 2014 6:33 am

Re: Floating resin in Bottom Up setup

Postby adambx » Tue Sep 16, 2014 8:58 pm

From the top of my head: "genius!"

it might be worth thinking about. I would reduce the amount of water to maybe 2mm at the most to not diffuse the light too much.
I might lose a nights sleep over it befor i can try ^^

If anyone tries, please post! :)

dangre
Posts: 116
Joined: Wed Jun 25, 2014 4:20 pm
Location: SW Michigan

Re: Floating resin in Bottom Up setup

Postby dangre » Tue Sep 16, 2014 10:14 pm

Um, unless I'm not thinking clearly...how could you get a 20-50um layer of resin to float on water under your build plate and do this consistently?
Dan - mUVe 1 DLP

Phife
Posts: 239
Joined: Fri Jan 17, 2014 5:24 pm

Re: Floating resin in Bottom Up setup

Postby Phife » Tue Sep 16, 2014 10:23 pm

dangre wrote:Um, unless I'm not thinking clearly...how could you get a 20-50um layer of resin to float on water under your build plate and do this consistently?


Good point, not sure, needs to be tested to be sure. It was just a thought. Couldnt hurt to try? Maybe start with a 100um layer?

I was thinking maybe salt water is not dense enough, perhaps a more viscous transparent liquid would be better. Im thinking mineral oil or glycerin..

Glacian22
Posts: 63
Joined: Wed Feb 19, 2014 4:23 am

Re: Floating resin in Bottom Up setup

Postby Glacian22 » Wed Sep 17, 2014 12:03 am

I've tried this with both salt water and glycerine, and neither works very well. The problem is that the build plate moving causes a lot of turbulence, as does the model rising and lower back into position. I found that I could get a few good layers, but then everything went woobly. That's a very technical term by the way. :D

Phife
Posts: 239
Joined: Fri Jan 17, 2014 5:24 pm

Re: Floating resin in Bottom Up setup

Postby Phife » Wed Sep 17, 2014 1:09 am

Yeah thats what I thought, Although maybe you would only have to raise your layer thickness, no need to raise then lower, perhaps even a constant movement upwards, although I dont think that would work right unless the resin was very low viscosity.

A continuous print slowly raising and instead of a slide show of slices you do a video thats showing blended slices, Would be awesome to see!

dangre
Posts: 116
Joined: Wed Jun 25, 2014 4:20 pm
Location: SW Michigan

Re: Floating resin in Bottom Up setup

Postby dangre » Wed Sep 17, 2014 8:59 am

First, I think coming up with 'out-of-the-box' ideas is what progresses any idea so I applaud your thinking. To break down a SLA printer is we are trying to cure a resin to give a 3D shape. Currently we cure small layers to build up the whole part. To get the smallest layers possible you need to create a small layer of uncured resin on top/bottom of the last cured layer. The idea of a video sounds great but a video is just a quick sequence of still shots. In conception, if you could present a new uncured layer of resin and quickly cure it you are doing just that. So the opportunity is how do we get that thin layer of uncured resin on top/bottom of the last cured layer. Yes, I too, lie awake in bed thinking of these opportunities just like you all...
Dan - mUVe 1 DLP

dpizzle
Posts: 43
Joined: Wed Aug 13, 2014 6:44 pm

Re: Floating resin in Bottom Up setup

Postby dpizzle » Wed Sep 17, 2014 5:38 pm

I like this idea a lot. There are some super high viscosity liquids out there like this:
https://www.youtube.com/watch?v=o9BNoKM_Glc

Searching on amazon there are some clear silicone oils with high cSt and are decently priced.
Might be worth exploring.

adambx
Posts: 119
Joined: Wed Apr 09, 2014 6:33 am

Re: Floating resin in Bottom Up setup

Postby adambx » Fri Sep 19, 2014 5:22 am

does the silicone oil stay separated form the resin? How about pigment, does it bleed to the saltwater? This could be a problem :/

tom-res
Posts: 19
Joined: Sun Feb 09, 2014 9:55 pm

Re: Floating resin in Bottom Up setup

Postby tom-res » Sat Sep 20, 2014 6:24 pm

based on the data sheets provided, the density of the high viscosity silicone oil dpizzle posted would not work for this application.
Density of silicone oil is 0.97 g/cm3 (http://www.clearcoproducts.com/pdf/msds ... _Fluid.pdf), while makerjuice resin is 1.1 g/cm3 (http://www.makerjuice.com/docs/SubGPlus-TDS.pdf).
I think this is a great idea though, and it would be awesome if we could find a chemical with a high enough density and viscosity!