Build Your Own SLA/SLS

Hello everybody.

I am new at SLA, so bear with me.

I have recently started to print with SLA using Makerjuice G+ resin, but that resin is transparent, non-pigmented. I have enclosed picture of my failure. I bought non-pigmented resin since I though it would be nice to have non-colored one, since it looked quite universal, but I honestly think that I was completely wrong.

Hardware: ACER 6510BD beamer.
I am using tensioned FEP film as vat bottom. XY resolution is ~100microns as well.

My questions are:

1. Is non-pigmented resin usable at all? As far as I understand now, light is able to go through the part completely, when it is transparent, and it can burn way more resin than it should, whereas when resin is pigmented, it is not transparent, so light will only burn visible region, avoiding deeper sections. However, when I did my research, I found that generally photopolymers, when exposed to light, will polymerize just a very thin layer of photopolymer. So I do not get that then...

2. As you can see, the part is pretty overexposed as I understand. I tried to use various exposure times like 4s, 8s, 10s, layer was usually 100 microns (XY - 100microns as well), but if I use shorter exposure times, those thin supports completely fail and the whole part becomes just a pile of small, detached particles in the vat/resin, which is quite difficult to filter and clean (and those particles like to damage teflon film), but if I use longer exposure times, you can see the result - it is pretty overexposed. Any solutions? Is it because resin is without pigment?

Thanks a lot.

Hi

As I can see from attached photo your problem is under exposure not over exposure. Object looks like melted because each layer is not cured enough (only partialy) so few layers combine together.

I had similar problem with Maker Juice G+ unpigment resin, but my printer is with LCD mask, about 20W powe of source. Solution was to prolong exposure tima. Good esults come when I put exposure for each layer around 17s !
Your printer have more powerful liht source so probably it will need shorter exposure time per layer.
At first you can try by increasing exposure time by 50% comparing to exposure time when you get photo.
For sure you will get better result.

If you will be satisfied with print quality, then you can slightly decrease exposure time for fine tune exposure, if not keep increasing exposure time by 20% in each new step until you get good result.

I hope this will be useful for you.

Happy printing!