Neosanding 2.0 - Faster cleaner top layers but... Different

[neotko 1,417]

Got this idea a few days ago, since now Cura has a Neosanding 1.0 (aka Ironing) feature, I though it could be fun to do something along those lines, but without the speed lost of re-sanding the printed layer.

So

The Theory

When using a 0.4 Nozzle (like I do most of the time) If you set the nozzle at a fake extrusion like 0.24 (for example) then, the nozzle path will 'hit' the printed part with half it's tip, scratching (sanding) the just printed part.

The practice

It does work, but not as 'sanded' as the 1.0 neosanding, ofc in exchange you do all in one pass, saving time. So where's the advantage? The top layers do look better, because you make much thinner lines, hiding the print lines better (on top layers ofc).

But to do so, 0.24, means that the nozzle will have to do more travel moves to print the same area as a 0.4, that's why I set the print speed to almost double of the real speed. This should decrease the quality, but because you are 'sanding' the printed part, and doing thinner extrusions, the result it's quite nice.

Mind that my top layers are done at 50mm/s. So when I use 0.24 for the sanding2.0 I set that at 100mm/s (for toplayers, not outlines ofc).

As you can see on the image the result it's less soft than sanding 1.0, but also, mind that this is the worst angle to see the effect, the texture to the hand is smoother and the normal view is quite matte. The advantage ofc is that I don't lost any print time.

The Extreme test

0.24 with a 0.4 nozzle is as low I can go without causing extrusion errors, but I though, well if you use more passes, it will sand even more, so let's test 0.1 with a 0.4 nozzle. (remember I'm talking not about layer height, but extrusion width).

So when you do 0.1, the result it's quite amazing, mind that this was a test I just done 2h ago, there's stuff that can be improved, like for example separating the perimeters so they are printed at 0.4 instead of 0.1

So that's it.

How to do it

First you need to select the last top layers of your print. In this case I used the 4.0 split helper, it helps but isn't all that it could be.

Mind that the numbers of the screeshot ain't the ones on the FFF files I uploaded (download at the end of the post).

So, you split the process on as many parts as top layers you want to make them 'beauty'.

Then, you group the 'neosanding2.0' layers that need the effect and adjust this parameters

This, ofc depends ENTIRELY on your print speed. I adjusted the outlines to match the ones I use on the normal process, to avoid loosing quality on the outside, but keeping a very high speed for the last layer solid infill.

And that's all.

This is how much passes does with 0.1 (mind that one square doesn't use the sanding to have a fast check vs)

So is this better than Neosanding 1.0 ? Not really, it's just faster.

Weakpoints

Since now you relay on the nozzle to sand the previus printed part, the gloss to matte effect changes if the foot print is small or big. If the area is big, it will look more matte, just because there's enough time for the filament to cooldown (cold enough to get sanded). So if the foot print of the toplayer is very small, the filament would not be cool enough to get sanded and will keep a half-gloss-matte brightness. To get a more matte effect, slowdown the 100mm/s speed to something like 75mm/s, that should give you a more matte finish, but will take more time to print than just a non-neosanding2.0 layers.

Files for test and check

This includes the FFF files to check how it's done

https://www.youmagine.com/designs/neosanding-2-0-idea-and-concept

WARNING - The starting/ending Gcode it's the one I use on my machines, IT WILL 100% make the hotend crush with the bedclips, YOU must change it to your machine. If you didn't read this, sorry it's your problem.

Also filament size, settings of the normal process, all, it's customized to my UMO+ with 1.75mm, Gudo ZGE Direct Drive, UM2 hotends 1.75 and custom fans. So EVERY setting will need to be readjusted to your system.

Disclaimer: I share this so users with basic know-how can understand the concept, I take ZERO responsibility if you didn't read this before using the FFF on your printer.

Edited August 6, 2017 by Guest

[neotko 1,417]

Add. Can't edit the main post due max words So I add it here. for the "In theory" main part.

Forgot to add that, the theory in my mind when doing this, was to keep the same mm3/s of extrusion, that's why I bump up the speed, but also because the faster you do the moves the easier is to have a 'sand' effect. So that's why it could be interesting to have a proper math formula behind to keep the extrusion ratio at the same level of the normal layers when doing this, to avoid changes on the extrusion flow that could lead into unwanted blops, extrusion errors, etc. Also that's why when using 0.1 (extreme and just for visual testing) it gives wrong perimeters and bad infill, but ofc, it gives the most smooth top layers you could want (mind the print errors due used on a process on s3d 4.0 without being able to split the perimeters from the toplayer, because 4.0 has a bug that breaks processes without perimeters).

[cjs 34]

Any chance this approach can/will be implemented in Cura?

[inventabuild 5]

Hi Neotko, did you ever develop Neosanding 2.0 with splitting the perimeters and top fill processes and verifying that it works great as expected.