Postby big bad jim » Mon Jun 09, 2025 10:59 pm
I may not get to everything tonight, so I'll start by answering the easy questions first.
All of these comments will pertain to resin 3d printing rather than FDM printing. I can speak about FDM printing in general ways, I've done it in the past, but I've have zero firsthand experience with any of the current consumerist level FDM offerings. Ten years ago I was printing on a $75k commercial FDM printer, which is a lifetime in technology years. I bet the $300 hobbyist FDM printers of today yield better results than I could achieve on that high-end printer.
I have both the Elegoo Mars 3 (smaller build volume) and a Saturn 2 8k machine (larger build volume). Both machines are several years old at this point, and at least two generations behind the newest offerings from Elegoo. As Jim mentioned, despite their age both machines are still perfectly capable, and in reality the improvements in newer models, or "improvements" if you're the skeptical type, are in categories of ease of use, reliability, and convenience rather than leaps forward in print quality or capacity. The newest Saturns are up to 12k screens, but the improvement in the screen pixel size is only marginally better than the older 8k machine. It also makes for a rectangular pixel rather than square, which is kind of goofy. On the flip side, they now offer things like easier build plate leveling (I never had issues doing it the old way), built in heaters for the resin (pretty easy to manage with aftermarket solutions), and wifi connectivity for sending files (walking over from my desk with a flash drive works fine now). On top of all the stuff I don't personally need, the printer build volumes on the latest Saturns have actually gotten smaller than the Saturn 2 8k version I have now.
The latest Mars versions are much the same with respect to the hardware improvements. They did however jump from a 4k screen to a 9k screen with the introduction of the Mars 4, which does actually make a significant difference in pixel size and therefore XY resolution. The current generation Mars 5 is back to a 4k screen, while the Mars 5 Ultra has the 9k screen. However, both models have smaller build volumes, so the Mars 4 is still the model with the best XY resolution and build volume among all the Mars offerings. I'm actually considering getting a Mars 4 to optimize my print quality, and they are even cheaper now than they were before.
The premise behind JIm getting a Mars 3 was that I could create 3d models and the corresponding printer files, which I could email to him. He could then print them models himself, saving time and cost. Send the data, not the media. We are using the same printer, the same resins, and the same techniques. It all works well as long as the printers are performing as they should. It didn't hurt that at the time the Mars 3 was already last year's model, and on sale for an absurdly low price, so the decision for him to get one was fairly simple.
Ventilation is a good idea, to control both odor and potential toxicity. Interestingly, it's not the resin that's a problem for me, rather I have issues with the 91% (or higher) isopropyl alcohol that I use to clean prints. The odor is much worse than for any resins I've used, and extended exposure will irritate my throat. I run a spray booth fan to an outside exhaust whenever I'm working with the IPA, and I wear a 3M respirator designed for VOC's at the same time. The fan also keeps the IPA fumes from permeating throughout the house.
Regarding sourcing files for printing, it's a broad question with many aspects to consider. It's also the sort of question where the right answer is "it depends" because there are so many variables to consider. Do you have cad skills already? Can you learn them? Do you have access to a viable cad program? If you want to or need to purchase models, then can you find what you want from any number of cottage industry vendors or larger operations like 3dCentral. Are you prepared to pay to have somebody else do the modeling? Or maybe the alternative is to source a file from one of the online 3d printing warehouses like Thingiverse. The big issue with free files is whether you can trust them to be accurate (they often aren't), which brings up the question of your modeling preferences. Can you find models that are done to the level of detail and accuracy that you prefer.
For myself, I prefer to create my own 3d models. I'm pretty OCD about things, so I've got trust issues. I'm also willing to go to often dysfunctional lengths for modeling fidelity, but it's my time and I can use it as I like. My advantage is that I have plenty of experience with CAD, and I have access to two or three reasonably priced and highly capable cad programs, so I can do the 3d modeling work myself. My greatest obstacle is sourcing accurate and detailed information that will allow me to do the sort of modeling I prefer.
Absent the skill set and the access to programs, the challenge will be finding an existing model available for purchase or free download, or finding a cad designer that will create the file you want. There are existing models of gazillions of things, free or otherwise. There are designers out there that do model railroad work. Unfortunately, I'm not the best reference for either case as I've never had much reason to utilize those options.
I'm going to have to wrap up for tonight, but I'll follow up tomorrow with some comments about the available cad packages, and some notes on my methodologies. If I can figure it out again, I'll get some photos loaded up as well. If I think of anything else regarding sources for files, I'll add that to the discussion too.
Jim
