3D Printing is anything but fast. So whatever you like to print, it’s often useful to be able to print faster.
Here I’m going to show you the key levers to pull to get faster prints, with minimal compromise!
Some you might know already, but I guarantee there’s a game changer in here you’ll likely use on every print after reading.
We printed out dozens of 10cm x 10cm test cubes (default: 0.2mm Layer Height, 60mm/s Print Speed & 10% Infill unless otherwise stated) to test our hypthosis to reach shorter print times.
There are two core factors that affect print speed: How much the print head moves and how fast it does that.
So let’s see how we can minimise both:
Sure it’s obvious, but less infill dramatically reduces print times. And it’s also really easy to do. To illustrate on our 10cm x 10cm test cube here are the print times for 3 infill percentages (with other factors remaining the same).
30% – 22 Hours 14 Minutes
20% – 16 Hours 26 Minutes
10% – 10 Hours 52 Minutes
“But lower infill percentage weakens prints & finish quality?” I hear you scream, in confused desperation. Well believe it or not, infill actually has very little effect on print strength and we can easily get that strength back (and then some) with more perimeters.
Keep reading to learn more.
As for finish quality, lower infill can cause pillowing and gaps on the top surfaces of prints, but you can increase infill in the top 5% or so before printing the final layers OR increase top layer count to combat that.
A small price to pay for significantly lower print times – might be worth experimenting with even less than 10% infill.
This effect is further minimised by choosing a superior infill pattern, which leads us to…
The Best Infill Pattern
“Best” is often subjective (but not really in this case). Printing identical 10 x 10cm cubes for the following popular infill patters, here are the printing times in order of fastest -> slowest:
1. Line: 10 Hours 12 Minutes
2. Rectilinear: 10 Hours 23 Minutes
3. Gyroid: 10 Hours 45 Minutes
4. Grid: 10 Hours 55 Minutes
5. Triangles: 11 Hours 15 Minutes
6. 3D Honeycomb: 14 Hours 53 Minutes
7. Honeycomb: 16 Hours 03 Minutes
Now while Gyroid isn’t strictly the fastest, it is the fastest true 3D designed infill, and the strongest in all directions. This means you can use less of it, and it also supports those top layers better minimising the risk of poor top surfaces with lower infill percentages.
Why would you ever 3D print without using true 3D infill? That’s like running 32bit software on a 64bit machine – a total waste of potential.
So unless absolute speed (at the expense of strength, choose ‘Line’) is your single priority, I recommend Gyroid infill.
Perimeters are the walls of your print. They’re important – so you don’t just want to go removing them because your prints will be really weak and your infill might even show through at some points, like some kind of weird 3D printing hernia.
In fact, if you’re skimping on infill % like I advised earlier, increasing by 1 perimeter actually claws back more strength than a higher infill (in most instances, because multiple perimeters has a far greater impact on strength than infill) and is way faster to print.
But what you can do (the secret trick) is to increase extrusion width, and reduce your perimeters to 2 because increasing extrusion width doesn’t actually affect print times at all and extrusion width plays a huge role in increasing part strength.
Here’s the times on our 10x10cm cube:
3 Perimeters: 10 Hours 55 Minutes
2 Perimeters (complete with a nifty 10-30% increase in extrusion width): 10 Hours 05 Minutes (8% Saving)
Just 8%? Yawn…
BUT! – Where reducing perimeters really comes into it’s own is when you’ve got loads of holes or arms or components on the model that cause lots of movements and retractions everywhere.
If we subtract 10 holes (I refuse to say ‘add’ holes) from our cube, here are the times:
3 Perimeters with 10 holes: 17 Hours 22 Minutes
2 Perimeters with 10 holes: 14 Hours 52 Minutes (14% Saving!)
(1 Perimeter is even shorter print times, but 1 perimeter is also crazy)
The most obvious way to reduce print times is to increase layer height, because this decreases the amount of layers (and therefore total travel distance) through your print.
Typically layer height by default is 50% of your nozzle width. So for a standard 0.4mm nozzle, you’re usually printing at 0.2mm. However you can increase this safely to 75% nozzle width (0.3mm Layer Height) without sacrificing printabiliy or strength (toooo much).
Our 10 x 10cm cube at 0.2mm layer height printed at 10 hours 55 minutes.
Same cube at 0.3mm? A 32% Saving At Just 7 Hours 35 Minutes
You will notice a small degradation of surface finish with the increased “step effect” but for most practical prints this acceptable.
This is where most people go wrong trying to increase print times. Just make the printer go faster, and you get a faster print – right? Well, that’s kind of like trying to make a heavy car go faster by just putting a bigger engine in it (looking at you, America).
See if you want high quality prints that are strong, you can’t go wrong printing slowly. Especially with flexibles. Which means printing faster leads to the exact opposite of these things.
That said, there’s a smart way to print fast. And that’s to print the bits you DON’T see as fast as you can, and the bits that you DO see a bit slower. Most printers can handle ~120mm/s, so an increase (from 60mm/s) to 120mm/s on the infill will reduce from 10h 52m down to 10h 14m on our 10x10cm cube. Another reason to use Gyroid pattern, because it’s smooth instead of jerking at angles, so it’s more suited to faster speeds.
On the outer perimeter wall, we can maybe just increase from 60mm/s to 80mm/s you can shave a further 25 minutes off that time above.
There are some parameters that you should keep slow, though, like: Outer perimeters, smaller perimeters, top solid infill and support as these are more prone to under extrusion or poor cooling, leaving a potentially awful finish.
Key things here is to make sure you print hotter (so layer adhesion is still somewhat good) and have enough cooling so your prints don’t curl and look melted as hell.
Supports are a waste of time and filament, so we should minimise or get rid of them as best we can.
Now while you can design and orientate your prints to reduce the need for supports, I’m going to assume you’ve done that bit and so we’ll just crack on with the cheats…
Reduce Overhang Threshold: Most prints require support on overhangs over 45%, but often if you’re tuned in well and have sufficient cooling, you can go further (try printing an overhang test to see what your limits are) – so 60% + overhangs aren’t unhead of.
Support Bridges Setting: Bridges are any flat unsupported sections of your model. Again depending on your model and settings, you might be able to get away with turning this off, shaving more valuable minutes off your print time.
Support Blockers: While custom supports are another topic entirely, you can tell your slicer to block certain sections you think you can get away without using supports – or areas that if the underside comes out ugly don’t matter as much to you.
And there you have it!
9 glorious ways to improve your print times, which when used in conjunction effectively can easily half your print times depending on the model.