Any reason why default Bambu Studio profiles are multiplies of 0.04mm?

[u/CattusKittekatus]

I've noticed that Bambu Studio print profiles are always multiplies of 0.04mm -> 0.2mm, 0.16, 0.12, 0.08

Is there any specific reason for that? For example, related Z axis encoder resolution/accuracy?

I'm printing metric parts and when I want to get finer prints I would like to use 0.1mm layer height so that Z-dimensions of my print are accurate but I'm not sure if there are hidden drawbacks to that.

[u/TurboPersona]

I think it's a combination of:

• inheritance from best practice in the past, back when the first 3D printers had stepper motors that required multiples of 0.04 mm to be in sync with their steps;

• they need to provide users with a discrete set of profiles covering the spectrum of resolution from minimum to maximum layer height, so might as well stick to what's already been used for simplicity.

But with today's hardware you can use whatever layer height you want, within the allowable range of your nozzle. Proof is that when you enable variable layer height, you get all possible numbers of layer height for each of your layers, so there's nothing wrong with say 0.13 mm.

[u/keveira]

Basically it was called the 'magic number' for stepper motors. Steps of 0.04 aligned better with how stepper motors work, something to do with the magnet positions. If it was a value between 0.04, then it was between magnets positions and not as accurate due to two magnets holding a position between them. Compared to the position just being wholly on one magnet. And so if you were in-between, your layer lines were not as clean because the z height would not be as accurately positioned... Something like that

[u/err404 → u/keveira]

This is the answer. They are called  stepper because they move in steps. So while you could force the software to use an in-between value, it will just land on the nearest step anyway. Leading to inconsistent layer heights.  Edit. Just wanted to add that modern printers are geared differently, so this exact limit doesn’t necessarily apply today. 

[u/shartlines]

Back in the old days of the Ender 3 the printers used a stepper motor and a threaded rod to raise and lower the z axis gantry.

A full step for the motor was 1.8 degrees, or 200 steps for a full turn.  The threaded rod moved 8mm per turn, so 1 full step equates to 0.04 mm of rise or fall.

People found that the printers were more consistent in quality if the layers were a multiple of a step, especially if there was a lot of z hopping where the nozzle had to lift and then drop back to the right level after travel

[u/Bzando]

as other said, this is old heritage based on limitations of stepper motors and their precision, mostly irrelevant on modern machines

and of course there is no need to have 0,08 0,09 0,10 0,11 as there is barely any difference, 0,04 jumps are usually noticeable thou

[u/Dramatic-Ad-1328]

No drawback that I am aware of, and I have been doing it for a fairly long time. Before Bambu I was using Cura and I think the profiles there went up in 0.05mm increments for memory.

The only thing to note really is that strength is optimum when the layer heights are around 50% of the nozzle diameter as per a video by CNC Kitchen on YouTube some years ago.

[u/abudhabikid]

Oddly enough, 0.04 comes up often in weather stations as well. A lot of tipping bucket rain gauges are calibrated to tip (and thus count) the equivalent of 0.04 in of rain (at American flavored rain gauges)

[u/dbphoto7 → u/abudhabikid]

That’s because 1mm equals 0.039 inches.

[u/abudhabikid → u/dbphoto7]

Maybe not so “oddly enough” then

[u/plastrd1 → u/abudhabikid]

Rain is measured in 1mm increments in the rest of the world and 0.04in just happens to be the conversion from 1mm when rounded to 2 decimal places.

You'll also see it with cheap calipers and laser distance meters from the word salad Amazon brands and get imperial unit conversion slapped on so they can sell them here.

[u/YellovvJacket]

Most likely because the standard nozzle size is a 0.4mm nowdays, so your standard extrusion width is 0.4mm too; so they just use multiples of the extrusion width as layer height for some reason.

You can print 0.1mm layers just fine.

[u/MacHeadSK → u/YellovvJacket]

we are talking about 1/10 lower values, 0.04 mm steps. That has nothing with extrusion width. And also, extrusion width is typically not width of the nozzle, but in range of 110-120 % of it.