Printing at .05mm  

Re: Printing at .05mm

Hey,
I´ve done many .05 layer height prints on .4 and .25 mm nozzles, it all works fantastic. There´s no other nozzle or really anything required, and the outcome and the details are astonishing!

Re: Printing at .05mm

Are these capable of going below 0.05mm layer height utilizing a 0.4mm nozzle?

For when it is needed, say on a contour that changes X or Y axis very quickly?

Are there any limitations if someone else needed to utilize below a 0.05mm layer height? Can the gcode or machine interpret the request correctly? Or is there a actual physical limitation stopping the user from utilizing below 0.04mm layer height?

I still think it would be fantastic to have 1/2 layer external shells, and internal full layer extrusions for dramatic contour changes.

Kind of how "print every other infill layer" works but more powerful and versatile.

Re: Printing at .05mm

So I don't have a 3d printer yet, so take this with a grain of salt.

As I understand it, the X/Y precision and Z precision are completely different beasts. The layer height isn't directly controlled by the nozzle diameter, but other things such as extrusion rate would definitely play a role when changing nozzle diameter, so switching diameters can definitely effect the actual print of the layer heights, but it isn't the primary limiting factor, which is about the precision of the 3d printer to move up and down on the Z axis.

As for nozzle diameter, as I understand it, the primary reason you would want to switch to a smaller diameter nozzle would be to print smaller details. The nozzle diameter has a huge impact on the effective X/Y precision. For example, if your nozzle diameter is 0.4mm you simply cannot extrude a line smaller than 0.4mm, so you cannot print details which are smaller than that, but remember switching to a smaller diameter nozzle greatly increases print time, since you will have to pass over the same area many more times if you are extruding a smaller line of filament. Switching to a larger nozzle of course decreases print time, but it also means you cannot print smaller features, so depending on what you are trying to print you may need a smaller nozzle. If you want to switch to a very large diameter nozzle, you may even need to upgrade the Hot End (or other parts of the extruder) in order to melt the plastic quick enough. Here's a Youtube Video that shows printing speed with a 2.8mm nozzle :).

There are many things which contribute to the printers maximum resolutions, including extrusion multipliers, filament material, heat settings, fan settings, nozzle specs, motor specs, and motor drivers, just to name a few. Of course I expect to eventually be able to print at the advertised 50 microns, but I don't expect to get that out of the box or anything; don't get me wrong, I would love to, but I doubt everything will be dialed in enough to get 50 microns. If you want to get the best prints possible you'll have to spend time calibrating your printer, and you'll have to do this again each time you use a new filament, since filaments are not completely identical in performance even if they are made of the same material.

I'm sure there are better sources on this kind of stuff than me :).

Are there any limitations if someone else needed to utilize below a 0.05mm layer height? Can the gcode or machine interpret the request correctly? Or is there a actual physical limitation stopping the user from utilizing below 0.04mm layer height?

The limitations here are purely physical. 0.05mm is already incredibly precise for a machine of this nature (DIY). You can certainly upgrade and calibrate the machine to push it past those limits, but it's going to cost a pretty penny :).

Re: Printing at .05mm

Only interested in the Z height specifically.

As a simple example, something that benefited from a accurate surface, but had a Unavoidable acute angle from the Z plane.

Can these machines accept a < 0.05mm layer height and not choke on the command?

I just assumed there was a limitation because I have never seen the question asked nor do the "specifications" of many of the i3 machines ever specify less than 0.05mm layer height.

But can they do less if asked?

Re: Printing at .05mm

Only interested in the Z height specifically.

As a simple example, something that benefited from a accurate surface, but had a Unavoidable acute angle from the Z plane.

Can these machines accept a >0.05mm layer height and not choke on the command?

I just assumed there was a limitation because I have never seen the question asked nor do the "specifications" of many of the i3 machines ever specify less than 0.05mm layer height.

But can they do less if asked?

The Official Prusa runs on Marlin, so I don't see why not. Here's a link where someone successfully printed down to 10 micron layer height using a DIY "Prusa Mendel", using the Marlin firmware. It may take some time calibrating, and possibly some upgrades, but you certainly can get lower than 0.05mm, but the average user shouldn't expect their Mk3 to print at or below 0.05mm out of the box. Rather, I should say they should expect it to print at 0.05mm, but it will take some calibration to get clean layer lines, as the lower your layer heights the lower your tolerance for error, so tiny errors make a bigger impact. Printing at 0.05mm is totally doable but may take some calibration out of the box to get perfect clean prints. Printing at lower resolutions is possible too but takes lots of time and experience/knowledge to do so reliably. The lower limit for dimensional accuracy is around 0.5mm on your average desktop 3d printer, but down to about 0.2mm for an industrial printer. This is purely about dimensional accuracy and not layer height limitations though. When printing a model your print will likely be at least ±0.5 mm off on any given axis when compared to the actual model on your computer. That doesn't directly tie to layer height, but hopefully that gives you an idea about the accuracy of FDM printers. The exact precision will vary greatly by many factors, including ambient temperature, enclosure temperature (if applicable), relative humidity, fan setting, heatbed setting, extruder settings, etc.

The absolute minimum step you can take is determined by the Step Rate of your motors and axis assemblies. The faster you can print, the worse the precision. There is a table on that page near the bottom which shows some examples and theoretical limits. I don't know the exact physical minimum step size of the Official Prusa, though it is determined by a number of factors which you can upgrade in the future if you absolutely need <50 microns and for some reason the Mk3 could not obtain it under the current assembly. I believe it can though, as that table says the configuration "most commonly found in Prusa i3 RepRap builds" already has a theoretical precision of 12.5 microns on the X/Y axis. I can't imagine the Z axis having a lower precision, as typically it is moving a lot less than the X and Y axes. Also remember the new trinamic drivers claim to have 256 microsteps, which would significantly increase theoretical precision limits.

I think it would be theoretically possible to get your Mk3 down to even 1 micron precision, but actually printing with that kind of precision would be next to impossible, as the filament warps slightly as it heats and cools, and filament rolls often vary by at least ±0.05 mm themselves across the roll, so you can't even guarantee exactly how much filament you are putting down, or exactly how it is forming as it cools. In theory though you probably could get the Mk3 itself that precise, but you would run into many other issues limiting your actual level of printed precision. 50 microns is a good expected minimum layer height, but it certainly is possible to get lower with enough effort.

Re: Printing at .05mm

That's more of what the question was focused on, simply having the tool in the toolbox for the job.

I have had a few things that couldn't be oriented better, and would have been beneficial to drastically decrease the layer height for those localized layers at less than the 0.05 limit I have always adhered to simply out of convention.

Re: Printing at .05mm

Another question along these lines:

Is the Z step height perhaps limited by the direct geared extruders ability to acuratly step at the low step rates a lower than 0.05mm layer height might require?

Not necessarily the limit on strictly the mechanical Z axis specific mechanical height attainable?

Is that even a factor, if I have defined the question clearly?