I’m used to higher resolution being an expensive upgrade, so the idea of nearly double resolution for a few dollars took me by surprise.
I’m talking about 3D printing. It was a couple of months after buying a 3D printer that I learned that you can buy different sized nozzles for the Prusa MK3S; that they’re so cheap as to be effectively free; and that while the default nozzle size is 0.4mm, it works fine with a 0.25mm nozzle—almost doubling the resolution.
So! I ordered some nozzles: and most importantly, the 0.25mm and the 0.8mm nozzle.
Why would lower print resolution ever be better—why would I be interested in changing from 0.4mm to 0.8mm?
Okay, I’ll spill the secret: it’s all about print time.
The reason I ordered a 0.8mm nozzle and the reason it was the first one I tried when the package arrived is that, for the same sized print, it prints hugely faster than the default 0.4mm nozzle.
For the first time I could print “human standard sized” objects—such as vases—in a few hours instead of 24 hours.
I have pictures. But first, a diversion.
I am really not at all mechanically adept, so the process pushes the boundaries of what I’m comfortable with.
Changing or replacing the nozzle
It’s fraught for two reasons.
First, there is a possibility of mechanical damage, and I really don’t want to break my printer.
Be extra careful around the fragile hotend heater and thermistor wires. You can break them off or short-circuit the heater with your spanner!
Second, you have to have the current nozzle heated to 280°C (536°F) before you unscrew it. Interacting with parts this hot is scary: anything in contact with the hotend heats up very quickly, and the instructions tell you carefully that you must place the removed nozzle on a non-flammable surface.
To screw in the new nozzle I had to hold it in my fingers to engage the start of the thread—an operation that had to be performed quickly before the nozzle heated up too much.
I am sure some of you are laughing at me through this description—as in, anyone who has actually done significant work or hobby work of this kind—that’s fine. I know my weaknesses! (Some of them, anyway).
Anyway, I have succeeded in two nozzle changes so far and nothing seems broken and for sure I didn’t get burned, so, yay for me.
Here are two vases!
They are not huge—just slightly too big to function as pen holders, suitable I suppose for small flowers. (They seem to be waterproof enough).
They printed in a couple of hours each, which might sound terrible but believe me, for a 3D print of this size it’s a good time. The lined texture is clear—that comes from the large nozzle size. I think it works well.
My favourite “super detailed” model is a fractal pyramid, I’ve shared a photo of it before:
So as a first test of high resolution printing I simply scaled the model to 50%—that’s 50% on all dimensions, so one eighth the size—ramped up the detail settings to max, and hit print. That was over an hour ago; it still has three hours to go. I’ll finish writing this when it’s done.
Update: well, that didn’t work very well. Two problems: first, I used an opaque plastic, when the model really needs transparent or semi-transparent to shine; and second, this model is particularly prone to stringing:
Stringing is when the print head does not fully stop printing at the instant that it should, leading to very fine plastic threads stretched between points that should not be joined.
I’ve read that you can carefully burn away the additional threads, but I’ve never had much success with it; here’s what the model looked like afterwards:
Undeterred, I tried again the next day with three changes. I switched to a translucent plastic, of course. For the stringing, the most common suggestion seems to be to “dry out” the plastic; who has time for that? I read an alternative suggestion to slightly decrease the nozzle temperature, so I lowered it from 215°C (419°F) to 210°C (410°F).
And thirdly, something I’ve glossed over so far. The nozzle size greatly influences the resolution in the horizontal plane, but the layer height can be configured—to some extent—independently. When I said “ramped the detail settings up to the max” I meant I chose the absolute minimum layer height, 0.05mm. For my retry I picked a more sensible value, 0.15mm. This dropped the print time to a mere 1h37m.
Result: much better! Here are some photos.
To give an idea of the scale, here it is with its bigger brother—remember, 2x in every dimension—and balanced atop its cousin the vase:
As you can see from that last photo, the difference in resolution between the largest nozzle and the smallest is something really quite dramatic—just as is the difference in print rate.
I’m glad I discovered these new options for printing. I don’t get as much time as I’d like to play with print ideas, and now I have more options! The nozzle attached right now is the 0.25mm one, knowing me I’ll be lazy and try things with that next.
So far today, 2024-11-25, feedback has been received 1 times. Of these, 0 were likely from bots, and 1 might have been from real people. Thank you, maybe-real people!
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