Cool, how stable is it?

oof, good luck enforcing that lol, the Benchy’s one of the most modified models out there.

The edits are really very simple, you’d just have to chop the model into a few pieces. I think windows has a built in tool that can do it. Actually I think it’s possible to print it without edits, by standing it upside-down on the flat bit at the top. However since the contact area is so small, and the print is so tall, it would be more likely to fail. I wouldn’t try it on my machine, but since you’re going through a print farm I don’t think that would be an issue, there’s no way they’d send you a failed print so they’d probably just print it again. You might get charged extra if they have to redo it? I don’t know how these companies work you’d have to ask them.

If you don’t want the glowing then I think there aren’t really any issues with printing that, as I’ve said some minor edits would make it easier to print, but it would definitely be sturdy enough.

I’m not a pro at 3D printing or painting, but I think I know enough to answer your questions.

Ok, so first thing out of the way- that model you linked is not made for 3D printing. To get a decent result you’re gonna have to edit it a bit.

This is intended to be a hand-held prop, not just a display model. So my first question is, is that even feasible? I don’t know how strong things like this are. I’m not going to be hitting anything with it, but a little bit of waving around I think would be in order.

Definitely feasible. There’s a wide range of durability with 3D printed stuff, but you’d have to go out of your way to make something that can’t handle that.

Assuming that’s ok, what material should I use? Not entirely sure I even get a choice but I think so?

PLA is the default, and it would work ok, you could also switch to PETG. PLA softens at a very low temperature- roughly 60°C. It’s not too big of a concern, but there’s a small chance of it deforming if, for example, you left it in a very hot car, or under a window that happens to focus the sunlight on it. For a prop like that you don’t have to get more fancy than that. You almost certainly get to choose- I don’t use these 3D printing services but I’d actually be slightly concerned if they didn’t.

Another question I have is about painting. I’ve seen painting guides online, but one question I have I didn’t find an answer to is again, about it being hand-held. I don’t want to use a paint that will come off or smudge with sweaty palms. Are any kinds better for that than others? Are any?

Even just regular craft-store acrylic should hold up decently well, but you should use a sealant/clearcoat/varnish. I don’t do this so I can’t help you much with that, but it should be as simple as just spraying the whole thing with it after you’re done painting.

And how close could I likely make it look like in the link? It doesn’t have to be exact, but there’s metallic parts, glassy parts, kinda gives a glowy impression… or is this going to be too hard for someone with no experience? (I’ve painted a couple of model kits when I was a kid.)

Probably not very close. The metallic parts are ok, there’s paints that mimic metal, they’re not going to look fully convincing but it’ll probably be fine. You can get glossy clearcoats too. The big issue is the glowing part. There are ways to make something look like it’s glowing by using gradients and stuff (look up OSL painting) but I don’t think that works very well at such a large scale, and it’s difficult. For something this big I think the only way to get a good effect is to make it actually glow, which is a whole 'nother can of worms. To make that part look good, you’re going to have to do a ton of work. I haven’t done anything like this before, but I’ve got some ideas for how it could be done.

Do you want to make a lightsaber, or specifically this lightsaber? If you aren’t particularly attached to this one I’d suggest looking for another model. Printables, Thingiverse, and Thangs have 3D models specifically designed for printing.

Besides reading the Basic Rules, which someone else has already linked, I suggest you check out a game on Youtube. Note that usually these aren’t an accurate representation of how most games actually go- Critical Role for instance is comprised entirely of experienced voice actors- but it’ll give you an impression of how the game runs.

Just don’t base your expectations of your players/dm on them.