There are actually three types of “SLA” machine using resins and light. There are some that use a laser, like the Formlabs Form 2, others use projected UV light, and others use a LCD screen directly beneath the print bed, the last two are usually referred to as “DLP” rather than SLA, but they all use the principle of curing liquid resin using UV light.
SLA prints can still have layer lines - the model is still built layer by layer, just as FDM does. The key difference is that with SLA, the “next” layer bonds more thoroughly with the layer “beneath” it (in SLA, it’s actually the layer above it as the print moves in the opposite direction to FDM) so layers tend to “blend” slightly and this blending can, with very low layer heights and the right model end up with layer lines being virtually invisible but with bigger layer heights and curved shapes SLA is quite capable of producing visible layers, just like FDM, so don’t get the impression all your prints will be perfectly smooth.
If you’re not that familiar with SLA/DLP I’d recommend learning a little more before ordering a machine. SLA printing involves a lot more post-processing than FDM and can be quite messy. Most resins require a special baking/UV curing process to get the best results and the devices to do this are not usually cheap. Print trays and resin also need to be stored and handled carefully - you’ll need to get used to wearing nitrile gloves - and I certainly wouldn’t recommend an SLA machine for the typical “home” office unless you’re quite experienced.
So the photon I got uses a lcd screen with uv led light under it. Correct me if I am wrong, the lcd starts all black color so no uv light gets thru, then when printing layers it opens individual pixels needed and enough light to cure a layer of resin shines thru, then repeats the process many times. So other lcd unit printers have lcd screens each individual pixel is a tiny uv light?
Lines should be no issue for what I will be printing. My current projects are parts to fix things inside of devices. One is for other headphones like this one, the part that is connected to the drivers in the second picture, it glues to the headphones housing and directs sound thru pipes inside it. As for strength this headphones shell project will take me some time, I think it should hold up with thicker say 1mm thickness as it is a oval object that will create much more strength when connected. I will just have to live with the lines, or maybe paint over it.
I have used the uv resin and just a uv light for headphones repair projects. Started with bondic then made my own stronger uv led lights setup. I figure make the models so they work then bulk print them as I will use them often. It is some messy stuff I know. Curing I have a uv light box with heater(a modded face towel heater) but strength really won’t be necessary until I tackle the headphones shell.
Hi @silviasol, DLP printers that project light onto the bed use chips covered with tiny, tiny mirrors that move, known as a DMD (digitial micromirror device). See here:
Sounds like you’re all set up with your own hot-box!
Interesting. I will be keeping my eye open for ebay auctions to get a deal on a high end sla used unit. Using lasers just sounds too interesting.
I just made my first design, check my new post please! Thanks for all the help!
