PLA Wall Thickness... what's a good size?

[greatestalive]

Can someone recommend what a good wall thickness is on prints using PLA? I'm printing stuff like vases, and mostly display items. Is 1/8" good or can I make it even lower? Is there a formula to use to determine which wall thickness would work best on a certain sized print? How am I supposed to know?

[Larry]

For really small parts of an project 1mm should be ok. For medium to larger areas 2mm should be the thickness of your walls. That's a general rule of thumb I use when printing, and it usually works out great for me.

[old man emu]

Larry,
Would you use those values for ABS as well?

OME

[KrypTONight]

1mm works well on PLA for me quite a bit. I don't usually print with ABS. Would that work too? I have had to scrap prints in the past due to bad judgement on wall thickness, but now I think I have the system down pat. It's not any system I can really write on paper, its more of a judgment type thing I think.

[CaptainObvious]

I have printed relatively large parts down to 0.25mm wall thickness in PLA, so it's more a matter of how much strength you need to decide the thickness. For example as a test I printed a spiral vase with 0.3mm wall thickness and it works perfectly well as a pencil holder.

[Egon van Engelen]

For some vases I used 0.4 mm (the size of my hot-end opening) this works really well if you use a spiral motion to print.
For all other work I mostly use 0.5 mm, I tried 1 mm but I didn't have the feeling the parts became more strong so I don't see the need for it really.

[CaptainObvious]

Good afternoon guys,

I've come across some more information on this subject that I thought you might appreciate.

When you 3D Print a part most printers will outline the exterior perimeter and interior perimeter walls of the part and then fill in between them if the wall thickness allows. Determining how much wall thickness a 3D Printer can successfully print depends on two things, layer thickness and raster width (width of a printed line).

On my Stratasys Fortus 3D Printer the raster width is 2x the layer thickness so if I have the layer thickness set to .007 then the raster width is .014 for each line that is printed. This means that I can successfully 3D Print a wall thickness as thin as .028 because the exterior perimeter and interior perimeter raster lines will touch each other, bond together and create a strong wall. If I make the wall thickness .035 then it will create a very weak 3D Printed wall because the exterior perimeter and interior perimeter raster lines won't touch each other and bond together as there is not enough space between the raster lines for the 3D Printer to print another raster line.

Any wall thickness of either 2 raster widths or 3 raster widths will create a strong wall. Any wall thickness between 2 raster widths and 3 raster widths is in the danger zone that will create a weak part that can easily be broken. Any wall thickness greater than 3 raster widths will allow the 3D Printer enough room to fill in the exterior perimeter raster line and interior perimeter raster line with more material and bond them all together creating a strong part.

Something to consider when designing a part for 3D Printing.

Of course changing the layer thickness also changes the raster width which will determine what wall thicknesses can be successfully 3D Printed at this setting. You have to do the math.

I don't know if the raster width to layer thickness ratio is the same for other 3D Printers, you'll have to determine this for yourself. As I mentioned in my precious post "what works for one won't necessarily work for another".

One thing I have in my wish list is a slicing software that could do variable thickness perimeters, that would automatically determine the optimum width of a perimeter so that it either completely fills the gap between an exterior and interior wall or leaves enough space for it to be infilled.
The later versions of Slic3r, IIRC, have variable width linear infill for thin gaps, so fingers crossed for one day seen variable width perimeters.