expensive is a matter of taste. The envisiontec 3SP costs well over 5K euros and can go up to 100K. You can only get a a price if you ask for a quote. Carbon 3D does not sell their printers you have to lease them. Formlabs does sell you a printer at 3.5K but you can't use third party resins, so you decide. I actually know some open-hardware printers which sell for 5K.

you can get an Anycubic Photon under $500, its a decent resin LCD printer.

The patent mentioned in the article is specifically for continuous SLA printing (no pauses for lifting/peeling between layers), which the photon and other similarly-priced models don't do. I have one of the cheap SLA printers, and the lifting can occupy over half the printing time depending on layer height/resin type. The continuous printing machines seem to start in the several-thousand-dollar range.

the rotating reflective polygon patent is this one https://patentimages.storage.googleapis.com/29/68/46/da50635... I think it is even more relevant but somehow it did not get posted.

You'd think laser printers would be prior art - a rotating mirror (usually a hexagon) was exactly how older laser printers would scan across the drum to form out the print.

You have to specify application in a patent. Riken desribed it for 3D printing in 1997 see https://sffsymposium.engr.utexas.edu/Manuscripts/1997/1997-2.... but did not specify the use of laser diode as it was quite new at the time. It got only invented in 1996 by https://en.wikipedia.org/wiki/Shuji_Nakamura who got a patent for the laserdiode but little rewards and fought with his employer over it.

true it is a nice machine.. but laser bundles have advantages. You can direct other wavelengths, sinter powders and get to much smaller features. All these LCD printer, do show a pixel size but not a real spec or accuracy. If you go really high end even for mask projection with UV led you need expensive lights see https://www.idonus.com/activities/products/mems-products/uv-... ... costs around 20K i believe.

I'm not sure which resin printing process you're referring to. Most of the time for consumer-grade resin printers like the one I have, you design your model with a drain hole and print it hollow so the resin can flow out (or add a hole before slicing). Printing fully solid is generally only for when you want it specifically to be solid.

> you design your model with a drain hole

That's indeed what I was talking about. It's a manual process to my knowledge.

And then you end up with a shell, which is not as strong.

To my knowledge, you can't really have this with resin:

https://all3dp.com/2/infill-3d-printing-what-it-means-and-ho...

Please correct me if I'm wrong :)

I use FDM and resin printers regularly. You can definitely do any infills you want, such as the ones shown in your link. It's not a manual process any more than it is in FDM printers.

Yup, just to add onto this, software like Meshmixer will automate most of this for you. It's still possible to get voids where resin will pool depending on your model, but there's not a whole lot of manual effort involved these days.

Thanks! I am behind the times on resin printers. What hardware/software combo would you recommend? (With FDM, I've happy with Printrbot/Cura).