Attach LCD to VAT

Question

I began build LCD printer and I want make some modifications.

What if I will place LCD below VAT? Will the display break when printing? what are the risks? I seen a lot of printers and all of them use PP material for VAT bottom and attach with a lot of screws. I want make more simple VAT-LCD constructions and I think this construction transmis UV light better

Answer 1

SLA printers have basically 2 expendable parts:

• The UV light source is only good for so long before it degrades and breaks.
• The LCD will become blind over time.
• The vat's lower surface - the build area - will get eaten by the resin over time.

Because of this, all commercial SLA printers come with a special film at the vat's bottom surface, a sacrificial surface and, as part of the boundary of the vat, also acts to protects the LCD from the resin.

Answer 2

The way you're thinking about using the LCD directly on the bottom of resin vat and cure the resin is a good idea, but there are several problems that I will focus on the main. as mentioned by @Trish some issues might occur to the LCD and u need to replace it. Except that you need to clean the vat some times after print and with LCD attach to it, you know...

But the main reason is that when the resin is cured in the bottom layer can stick to the bottom of the vat so the printers have a solution to raise the bed and again lower it.

The FEP (Fluorinated Ethylene Propylene) membrane is an elastic material, so when the bed raises the FEP film get raise a little sticking to the part and detaching. so we cant have this situation with the lcd because the lcd is a solid film that bends just a little.

I'm also working on an LCD resin base printer so please post questions if you have any other questions.