There are a number of machines on the market and as with all technology they are evolving all the time. My choice was between the Elegoo Mars and the Anycubic Photon S. Reviews etc showed very little to choose between them, so in the end I went with the Photon S simply because that what Steve has and I thought that if I needed any help, that was a good place to start!
Trevor Thompson wrote: ↑Sat Dec 05, 2020 10:25 pm
So I am intrigued by the details:
You mentioned that the print had to be post cured and then washed.
Does that need special equipment or can the curing be done in the printer after it has finished building?
Is the washing just ordinary water and a tap?
Ok, firstly please remember that I am still very much a novice with this machine and much of what I know is still book learning!
I found that there are quite a few accessories that are helpful to go with a resin printer, because of the way it works.
First thing to remember is that the resin is cured by UV light which means that even in the UK, sunlight is enough to slowly cure it.
The printer works by shining focused UV light through the transparent bottom of a vat of resin and curing a fine layer of resin onto the build plate, followed by the plate moving up fractionally and a second layer fusing onto the first layer, and so on. During this activity any stray UV will have a slight curing effect on material in the tank and eventually some of this will become solid/large enough to interfere with subsequent prints. For these reasons it is essential to only pour the remaining resin back into a uv proof container ( its bottle) through a filter funnel.
The resin itself is slightly viscous and draining it out of the resin vat/tank/tray takes some time so I made a stand to hold it whilst it drips. There are a number of designs on Thingviverse, one of which I modified slightly so that I could print the parts on my Qidi.
When a print is finished, although much of the resin will have drained off, it will still be wet on the outside. This resin film needs to be washed off and the commonly used wash liquid is IPA, which can be bought in 5litre bottles online. There are resins which claim to be water washable but I have no experience of them and they are more expensive. How the price compares with ordinary resin plus IPA I have no idea.
Once washed it is recommended to give a final overall UV cure to ensure that the outer surface is hard. Although sunlight will do it, we don't get huge amounts of that and I'm impatient, so to speed it up requires a small UV light of the type used to cure false fingernails ( I'm told!), plus ideally a small turntable. Place the print on the T/T , put the light close to it, enclose it all in a reflective box, switch everything on and leave it for half an hour.
IT IS VITAL THAT THIS PROCESS IS ALL INSIDE A UV-PROOF BOX TO AVOID DAMAGING YOUR EYES.
It is possible to get combined washing and curing boxes. Anycubic do one which costs about £120. When I was looking at buying my printer I asked Steve about these and he suggested that they aren't necessary. He's right, my lash-up seems to work ok, although part of me thinks it would be nice to have it all in one piece of kit, rather than makeshift bits spread around the bench.