a new resin + a new Sla printer that would handle dissolvable supports. this is for sure absolutely impossible on an SLA, but why not thinking about it?
Because single material print, that’s why. There is currently no material that can be solidified in different ways such that one part is soluble (in whatever material… water, a base, an acid…) while the rest isn’t.
It is worth talking about getting rid of the supports though. Some concepts are being experimented on like printing in a gel.
This is also kind of what some industrial SLA machines have been doing since the beginning, by inverting the process Formlabs uses currently : they polymerize the surface of the resin in the vat instead of going through the vat, such that the part printed is always immersed in the resin and thus needs much less supports, because no peeling and less effect from gravity.
Then there’s more advanced polymerization techniques which allow the same bottom-up approach as Formlabs but without the peeling operation thus theoretically reducing the ammount of supports. See this video of the Carbon M1.
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One thing also is that if you can reduce the amount of resin in the tray (just enough to cover the bottom) then I think the print quality can increase
Variable laser power might render the supports undercured and desolviable.
A highbred resin that reacts to two different wavelengths, the one used for the supports results in material that can be washed away?
How about just getting a printer that can print in multiple materials with SLA quality surfaces?
The Connex does that pretty well- and moreover, the second material doesn’t even have to be a support material- you can use it to print a part that has some parts rubber and others resin- in a single print… or come parts flexible plastic and the other hard- or mix transparent materials with pigmented materials.,
But a Connex costs as much as a house.
And will continue to until the patents on that technology run out.
About the only way I can see around your suggestion is to have a TWO tank SLA printer.
The Supports get printed in a separate print run- first- since the supports are, by definition, supported.
And then either the tank moves over for a second tank- or the platform repositions over the second tank, and the printer builds the resin on top of the pre-printed supports-
This would work really well because the top of the support structure could literally be in the form of a negative ‘cradle’ or ‘print’ of the intended surface ( no little points to cut off ) but it would be really hard to pull off with Internal supports. You would not want to be moving the platform from one tank to the next repeatedly to print internal supports layer by layer- separately from the hard resin printing… as that complicates and slows down build time considerably…
But- technically- it could be done. A simple lazy susan carousel to rotate different tanks under the build platform and over the exposure window would help prevent misregistration, and would actually enable you to have as many different materials in a single print as you have tank space for on the lazy susan.
If this were coupled with an LCD exposure- rather than the slower laser spot drawing method, It might be feasible in regard to print times.
The key obstacle is that the print lifts out of the tank wet- and so dipping into the next tank would contaminate the other material.
That means you would have to clean the print between each actual UV material being used… so now one of the stops on the lazy susan is a form wash…
as you can see- there are good reasons why no one has come up with such a machine.
As to using different lasers to affect one resin in different ways- I don’t think chemistry really allows such a solution that would be workable… that it- it might technically be possible- but it would not allow the range of material properties that UV resins CAN have when they only have to polymerize in a single kind of chain.
I hadn’t thought about that option of printing the supports first. It might be an issue that the print is upside down though.
I think though something that would help print quality significantly is to reduce the amount of resin in the tank so that basically you only have enough resin to cover the bottom of the tray where the part is printing, by reducing that it should reduce the amount of indirect curing and the areas around supports should be cleaner.
I think there’s been some research around using different wavelengths of light to stimulate different photo-activators, but nothing that’s made it even close to a production product as far as I’m aware.
Some other interesting links I came across while researching this in the past:
https://www.aerotech.com/media/246109/TwoPhotonPoly.pdf
https://groups.yahoo.com/neo/groups/diy_3d_printing_and_fabrication/conversations/topics/6907
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Another thought- I don’t know how accurately the build platform of the Form 2 is locked in place… but potentially, one could run TWO Form2s… one running a support resin that is easily dissolvable… the other running the build resin… and simply swap the build plate from one to the other.
This would enable an intermediate step in which the dissolvable resin would be able to be cleaned of liquid resin and dried before putting the platform in the other Form2…
But even then, this seems like a huge complication in the printing process.
A two material UV printer like the connex would be preferable- we just need one at a reasonable price.
Mixing resins and the fact that the second tank would meet a model that has a part too big on the Z axis than are two huge points making this method unsustainable.
As for the Connex machine you’re talking about this seems to be very similar to Stratasys’ PolyJet and HP’s Jet Fusion printers and the price won’t go down until the R&D cost have been absorbed and/or until the respective patents run out, which is what happened with SLA and what allowed Formlabs to sell the Form2.