Slowing Down: Speed Settings for Fine Detail
"Slow it down" is the standard advice for a print that came out badly, and it's usually right. But slowing everything down turns a two-hour print into a five-hour print for a benefit you'd get from changing one number.
Here's which speeds matter and which don't.
Outer wall speed: the one that matters
The outer wall is the only surface anyone sees. It's also a small fraction of total print time — most of the time goes on infill and internal walls.
Which means slowing the outer wall is close to free. On a detailed print I'll drop it to 30–50mm/s while leaving everything else at normal speed. The finish improves noticeably and the print takes maybe ten percent longer.
If you change one speed setting, change this one.
Why slower helps
Two reasons.
Time to solidify. Plastic comes out molten and needs to set before the next layer lands on it. On small prints each layer takes seconds, so there's little natural cooling time. Slowing down gives it more.
Less mechanical stress. Fast direction changes make the whole printer shake, and that vibration shows up as ghosting — faint repeated ripples after sharp features. Small detailed models are all direction changes, so they suffer most.
Small perimeter speed
Many slicers have a separate speed for small perimeters — short closed loops, like the walls of a small hole or a thin protruding detail.
These are exactly where things go wrong, because the nozzle is doing a tight loop with no time to cool. Setting this lower than your normal outer wall speed helps a lot on models with small holes or fine raised detail.
First layer speed
Always slow. This is not the place to save time.
A first layer laid down fast doesn't get pressed properly into the plate, and the print fails hours later. 20–30mm/s is normal and worth every second.
What to leave fast
Infill. Nobody sees it. Run it as fast as your printer manages cleanly.
Internal walls. Also invisible. Speed these up to buy back the time you spent on the outer wall.
Travel moves. Faster travel actually reduces stringing, since there's less time for a string to form.
Top and bottom surfaces — moderate is fine. Slowing these slightly helps if your top surface looks rough, but it's second-order.
Minimum layer time
The setting that solves the small-print problem more elegantly than a blanket speed reduction.
It sets a minimum duration per layer. If a layer would take less than that, the printer automatically slows down to fill the time — giving the plastic a chance to cool.
The benefit is that it only kicks in where it's needed. Big layers print at full speed; tiny ones slow automatically. On a model that's chunky at the bottom and detailed at the top, this is exactly the behavior you want.
Setting it somewhere around 8–10 seconds is a reasonable starting point for small detailed work.
Cooling matters as much as speed
Slowing down buys time for the plastic to solidify. Good part cooling does the same job faster.
Make sure your part cooling fan is running at full for small prints, and that nothing is blocking the duct. If your fan is weak or partially obstructed, you'll be slowing the print down to compensate for a cooling problem.
The practical combination
For a small detailed piece, what I actually set:
- Outer wall 30–50mm/s
- Small perimeters slower still
- Infill and internal walls at normal speed
- Minimum layer time around 8–10 seconds
- Part cooling at 100%
- First layer slow, always
That gets most of the benefit of a "slow" profile at a fraction of the time cost.
Does anyone else find it physically difficult to slow a print down voluntarily? I have to talk myself into it every time. 🫠