[ADDED] Slicer behavior for thin walled sections

[CaliberMengsk]

How is this still not put in place? Can't even print a ring, cause parts of it would be floating due to thin walls being removed, yet free software like slicer and cura have no problems making a thin wall?

[Jeff_Birt]

Why not design your parts so that they can be printed? Just a thought...

[mroek]

I agree that designing parts for printing is clearly the most sensible way, but I think (as was suggested in the very first post in this thread) that S3D should have a checkbox to allow printing even details smaller than the extrusion width. However, this should be OFF by default, and S3D should just warn the user with a popup if the current job will omit details due to size, and then offer to turn it on (like it does now if manual supports are added but support generation is turned off). The popup should also warn that printing these details will not be accurate (since they are in fact smaller than the extrusion width).

This is however the lesser of the thin wall issues in S3D, the main issue is the crappy wiggly fill it does for any walls that are an odd number of extrusion widths wide. I'm really hoping the next version fixes this, and that it will be out soon. The wait has been long now.

[pipaev]

Why not design your parts so that they can be printed? Just a thought...

Why not design the whole production process to meet the restrictions of this software? Or whole life?

[Jeff_Birt]

If I design a part to be made on a particular type of machine then I have to keep that machines limitations in mind. It does not matter if the machine is a CNC mill, or a 3D printer. For example the minimum kerf of a plasma cutter, laser cutter and water jet are all different. So if I am designing a part I will have cut via a plasma cutter I cannot have features with a smaller slot with than that of the plasma cutters minimum kerf.

If you design a part for 3D printing with 0.2mm walls and want to print it with a 0.4mm nozzle it won't work 'as is'. You can design the part knowing that you are limited to a 0.4mm wall or expect the slicer to change the design for you. If the slicer does it for you it might seem easier but what you are printing is not what you designed.

I design a lot of functional parts that are 3D printed. If I need machine threads in the part it is designed to accept a brass threaded insert. If I were going to machine the part out of metal I would not design it the same way. Your design HAS to take account of the manufacturing process, that is the point I'm trying to make. I'm not trying to say that the software can't be improved to handle cases where you are provided files to print and must fix them up after the fact.

[dkightley]

A point of view well made...and I totally agree with this where engineering components are concerned that need to be accurate.

But there's still issues......firstly, if there has somehow been a section accidentally incorporated that IS too small, the slicer misses the area out and carries on as if everything is fine. No warning or indication that there may be an issue in the design. This is where one aspect of the feature request would come in......if the slicer misses a bit out, let's have a warning message.

And secondly, what about those who do "artistic" prints....who don't care about dimensional accuracy and download someone else's design and rescale so its smaller and then want a print. They effectively can't do this if there's a wall that ends up too thin. Enter a second aspect of the request....have a flag to instruct slicing of walls that are too thin at the thinnest the slicer can handle. The end result may not be dimensionally accurate....but it won't be crap!

And anyone thinking the discussion is going in circles.....yes it is!

[upsm]

If I design a part to be made on a particular type of machine then I have to keep that machines limitations in mind. It does not matter if the machine is a CNC mill, or a 3D printer.

At the moment, with Simplify3D, we are not hitting the limits of "the machine" but we are hitting the limits of software (Simplify3D in this case) long before we hit the limits of the machine!

And anyone thinking the discussion is going in circles.....yes it is!

Well if we had some feedback from the Simplify3D dev team (other then, "please don't discuss how it can be solved with other software", "please do not trash-talk Simplify3D", "we will `eventually` release an update", "we are working very hard but we won't tell you on what" etc) on the matter maybe the circle would be broken but since we'r treated like mushrooms all we can do is run in circles

[mattstrike]

Not to add more fuel to the fire, but I design many functional parts (brackets, adapters) for use in automotive projects, where final dimensions and overall model strength are required. I use Catia V5 to design parts, then export them to .stl.

I've noticed an issue that I think is related to this threads subject with my prints. My example is with a single perimeter gap between thin walls, where the wall thickness total is less than the wall perimeters setting.

My printer has a 0.4mm nozzle (I've tried auto extrusion width as well as force overriding to 0.4 and 0.38). One would think that as long as my wall thickness is a multiplier of 0.4mm I should always have a solid thin wall as long as it's thinner than the perimeters setting.

Pictured below; setting is for 5 perimeters, so in theory any wall less than 4mm thick should be solid. The wall below is 2.8mm thick, so that should be 7 perimeters. The behavior however is to print 3 perimeters through that section of the model on each wall and then leaving the center not printed/a gap, even if I use 100% infill.



I haven't found a setting that fixes this yet, other than using Cura (which, I spend $$$.$$ on S3D so why would I want to do that?). It's rather annoying for really thin walls, like 1.2mm, where they print as two 0.4mm walls with a 0.4mm gap between them. Right now the only way I can get a clean print on thin walls is to orient them such that they are printed in Z, not X and Y as in the picture above. I should note that this gap doesn't happen on the top/bottom layers, it only exists inside the shell.

[ururk]

I haven't found a setting that fixes this yet, other than using Cura (which, I spend $$$.$$ on S3D so why would I want to do that?). It's rather annoying for really thin walls, like 1.2mm, where they print as two 0.4mm walls with a 0.4mm gap between them. Right now the only way I can get a clean print on thin walls is to orient them such that they are printed in Z, not X and Y as in the picture above. I should note that this gap doesn't happen on the top/bottom layers, it only exists inside the shell.

I have had issues trying to get solid thin walls as well. Ideally, a 1.2mm thick wall, with a .4mm nozzle, will print four outlines and no gap. Instead, I often get 3 walls and a gap. I've tried (with some limited success) tweaking the extrusion width so that it prints the way I want, but then I wonder/worry that other parts of the design might not be printing correctly.

I suspect it has something to do with how S3D assumes filament flows, and that the width specified is expected to grow a little bit beyond what is configured. Such that, a .4mm extrusion width will actually be .41mm when printed. However... unless it was stated in this thread somewhere... I've never seen a reference on what this formula is or what S3D is doing.

Don't get me wrong - I use S3D nearly every other day at work - and really like the product - but this one behavior that frustrates me when I'm setting up a new design.

[AMAST]

I'm for having some thin walled options to add more perimeter shells as infill not zig zags. Thanks for your hard work.