GT2 tooth on x carriage not visible in slices

Hi,

I'm trying to print a spare x carriage for my Prusa but the tooth for the GT2 belt are not visible in the slices. Can someone explain this? Of course I only noticed this after printing the part... :-(

I've got the stl file from thingiverse. I guess I did not set the correct line thickness...





Edited 1 time(s). Last edit at 04/04/2015 06:17PM by kasperfish.

So I sliced with a smaller width for the perimeters and now the teeth for the GT2 belt is showing. Apparently 0.5mm perimeter width is too much. If I slice @ 0.4 mm perimeter width the teeth are visible in the slices/layers. However my nozzle is 0.4mm so is it acceptable to do this?

grtz

It's perfectly acceptable. I would say even recommended, meaning to set all extrusion widths equal to 0.4 mm. Moreover, to prevent some issues with thin walls, you may want to set the nozzle diameter to 0.39 mm instead of 0.4 mm.

How can a .4 nozzle make a .4 width? Doesn't the width always need to expand a bit?

Maybe the .39 setting is a trick for this.

width = ~ 1.5 x height.
height = width / 1.5 = 0.4 mm / 1.5 = 0.26666666666 mm
With a 0.4 mm nozzle printing a layer height of 0.3 mm should be no problem.
A layer height 0f 0.266666666 mm means a width of 0.4 mm!

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Quote
RRuser
How can a .4 nozzle make a .4 width? Doesn't the width always need to expand a bit?

Maybe the .39 setting is a trick for this.

If extruding static into thin air, yes. But when printing the moving nozzle will stretch the extrusion so it can be made very thin indeed. Consider: The volume of plastic laid down over the move is controlled by the amount of filament extruded. The height of the extrusion is constrained by the layer height (distance between nozzle and previous layer). The length of the extrusion is controlled by the distance of the move. So we can directly control volume, height and length. The width thus becomes a dependent variable : width = volume / (length x height). There are limits - the extrusion will be too round (not flattened enough) or will not even fill the layer (not be high enough) if the width is close to or less than the layer height so you should decrease the layer height if you need particularly thin perimeters, and if too thin the extrusion will tend to break up if printed too fast - but it can certainly be printed quite a bit thinner (or wider) than the nozzle diameter.

Dave