SLA printers, DLP vs SLS vs LCD

[tkdlachlan]

Hey dudes,

I'm working on building an SLA printer, and I've found one method of printing using an LCD screen in the same way you would use a projector in a DLP printer (Projecting the image of the layer beneath the resin), This method seems effective, in the very few videos that it is displayed and uses photo-polymers instead of UV resins. And that is my question, this method seems rather inexpensive for an SLA printer, but there must be something i'm missing, what are the draw backs to this method that I'm missing, and why is this method not more common?

Thanks!

-Lachlan

[curious aardvark]

The obvious drawback would be the resins.
Anything that is sensitive to just light - is going to be a real sod to handle and store.

There is a uk company that uses led panels as large as 72 inches to make sla printers. So it does work - you just need to get the resin issues sorted first.

[tkdlachlan]

This company (http://photocentric3d.com/?v=6cc98ba2045f) sells daylight polymers, so it seems fairly obtainable and i can't imagine it would be too much different to handling UV resins. Ive only found one statement in a comment section on a youtube video saying that there is a quality drop in lcd when compared to DLP printing, but i can't think of a real reason why that would be.

[awerby]

At the recent Inside 3D Printing show in San Diego, I saw some output samples from Photocentric's LCD printers, and they looked as good as DLP prints to me. But they may be using better screens than the one in that YouTube video.

[ChiTu 3D]

Offline control system for DLP 3D printer————ChiTu D Series

support@chitu3d.com

[curious aardvark]

well the handling problems would be more complicated for simple reasons.
Uv light makes up a very small part of the visible light spectrum.
So you can transfer and handle resins more easily and with less degradation (solidification) than a visible light resin.

You also need to make sure that the print area is opaque to light as well.
I don't suppose they're particularly difficult issues, you just need to take more care when using the resin that no extraneous light enters the printer.

[ChiTu 3D]

LCD screen PPI needs to be higher than 500, LCD screen is very cheap, there is a great advantage