[victorhooi]

The article states it is specifically geared towards FDM (i.e. filament) 3D printers.

I wonder if anybody with more experience knows how much of this would overlap with SLA (i.e. resin-style) 3D printers.

For example, there's rough guidelines like, overhangs are less of an issue with SLA - and the Z-height is ultimately what most affects print-time, but would be great to see something more in-depth here, with some engineering behind it.

Or if there's similarly in-depth articles for resin 3D printers?

[WillAdams]

It should be much the same except no layer lines or other aspects of squeezing stuff out through an extruder incrementally.

[alnwlsn]

From when I was briefly working with "personal" resin printers (elegoo, anycubic, etc):

- In terms of strength, print orientation doesn't really matter.

- The z height is pretty much the only thing that affects print time since it exposes a single layer all at once. So it takes the same time to print one item as it does to print with a bed full of them.

- The supports in resin aren't to push the print up like FDM, they are to pull the print up. Each layer needs something above it to pull it out of the vat for the next layer.

- Unlike FDM, the surface attached to the bed isn't normally used as one of the finished surfaces. The printer usually exposes the first few layers long to make a solid base which is well adhered to the bed. If you want good surfaces all around, raise your part up a bit and use supports.

- It's pretty unusual to not use supports in resin printing.

- It can help to orient the print so that the least cross section area is in contact with the FEP film at any given time. This makes it less likely for the print to get stuck to the bottom of the vat.

- Resin parts don't really have a concept of infill. You either print hollow parts or ones that are 100% solid (you never print FDM parts at 100%). If you print hollow, make sure you have a way to drain out the resin when it's done printing.

- Even if your print is open at the top, it can still become filled with resin during the print, like putting your finger over the end of a straw. Make sure this doesn't suck up all the resin in your vat, or put a somewhere so air can get in.

- The whole business of washing and curing parts is more than I can get into here. Of note is that you can't really cure the "inside" of a part because light from the outside only makes it so far in.

- Resin parts tend to be very brittle. I once pressure tested one with 800 Psi CO2 once, through a small printed tube, and it held, but it would break if you hit it with a hammer. We tried the "tough" resins too, but never got any result comparable to even regular FDM with PLA. I used to say that I thought of resin parts not as a solid piece of plastic, but of finely powdered dust particles glued together.

- Large resin parts warp, badly. Dimensions will be accurate on the small scale (millimeters) but not on the large scale (10s or 100s of millimeters). Not sure if it's because there's a good amount of force pulling on each layer during the printing process, or from stresses introduced during the curing process.

I mostly make mechanical parts. Between the messy processing, weak materials, warping that throws off dimensions, and health concerns surrounding the resin (not to mention the intolerable smell), I pretty much gave up on resin printing. Any more, if I need something that must be resin printed, I'll order it from a professional service (which have both better performance resins than the home gamer can get and the correct setup to deal with them).