Cura 2.3 (same on 1.5.4) slicing / printing tapered edge issues

[canadadrones 1]

Hi guys need your help again.

I am designing and printing cookie cutters from a simple line object.

I basically extrude the curve objects to create vertical walls (0.8mm wide for 2x passes from the Ultimaker 0.4 nozzle) and I am trying to get it to taper to super sharp (ultimate zero)

I realise the limitation of the printer so I get it that I will not get the final edge razor sharp... BUT... I want it as sharp as possible.

The 3D model is perfect in the sense that it has taper to razor sharp but then in CURA it must detect the machine/program/parameters limitation and grey out the last 7-8 layers telling me that they wont get printed at all...

That results in my wall at 0.8mm with no taper at all on top of it...

I would like Cura to give me something like this:

Here is the Cura visual cue that I will not be pleased with the print.

I tried in this file to build my walls wider... 5 x 0.4 so 2mm wide.

Just in case Cura/Ultimaker cannot understand putting the edge tolerance in between the "grid" of 0.4 nozzle size "cubes"

I would appreciate any inputs on what I am doing wrong and if anyone got to print super edges...

Thanks!

[neotko 1,417]

Well with a 0.4 nozzle on S3D (and cura will do the same) I can go down to 0.22 line width (option name in cura). So since Cura doesn't allow single width lines you could just do that. Ofc it will take longer to print.

You could make the object in two parts. Bottom and all non-sharp areas one object and thr top sharp other. Then, drop them in cura, merge them so they fit as you designed them and then use per object settings, choosing a smaller line width for the sharp area and leaving the bottom no sharp at the default line width.

Once merged usr Ctrl Click to select the top prt and click on perobject settings icon that's on the icon list of the left.

Edited December 9, 2016 by Guest

[DaHai8 74]

... So since Cura doesn't allow single width lines you could just do that. Ofc it will take longer to print....

 

Wait, what, huh???

I print single width walls all the time in Cura (.4mm walls with a .4mm nozzle). Ok, maybe not 'all' the time, but I have done it.

Just set your Wall Thickness to .4mm and 100% infill and set your nozzle to .39mm. You'll get at least a .4mm edge on your cookie cutters.

P.S. Hope your printing in PLA, 'cause I'm not sure you'd want to have bits of ABS in your cookie dough (not that PLA is entirely edible either...)

Edited December 9, 2016 by Guest

[neotko 1,417]

Well the Gcode viewer isn't much exact, but what you see is the nozzle going forward and back, so is a 0.8 wall. Get a caliper to double check

Play with the settings for thinner effects

[gr5 2,177]

@canadadrones - well I've made cookie cutters and even 1mm thick cookie cutters are quite sharp enough in my opinion.

If you really need them sharper then you need to print them on edge I suppose. If you print them vertically then you can get them as sharp as you want. But now you might have support issues.

Or you could use a smaller nozzle such as a 0.25mm nozzle (and tell cura it's actually 0.2mm) and now you can get super sharp.

But really I found 1mm plenty sharp.

[DaHai8 74]

It's somewhere in between:

Not quite a single wall, but definitely not two walls.

I had made some test strips a few months back to check different colored filaments and their translucency at various thicknesses: .4mm, .8mm, 1.2mm, 1.6mm, 2mm

And here are the results when printing with the nozzle size set to .39mm, single wall, 100% infill:

.4mm = .53mm

.8mm = .88mm

1.2mm  = 1.25mm

1.6mm = 1.68mm

2mm = 2.08mm

Edited December 10, 2016 by Guest

[canadadrones 1]

Well I say cookie cutters but really it's to cut fondant for cake decorations.

It's simpler to say cookie cutters than explaining the fondant

Anythow, I did the .22mm trick to get a few more layers printed and Thanks for the 2 objects that I can merge and change each proprieties separately, this can come handy.

So the result is that it gives me an ok edge but not as much as I was hoping for.

I have other nozzles that I can try... guess I have to give it a go.

Oh and if I do an edge layer it will not be strong enough and break too easily...

I will report back when I get time to retry.

[gr5 2,177]

>Oh and if I do an edge layer it will not be strong enough and break too easily...

It shouldn't. There should be no "grain effect" with PLA.

If you are printing ABS and you are getting bad layer bonding this is very common but pretty easily fixed. Mostly by reducing the fan to zero or close to zero. With UM3 I would try 1% fan. With UM2 I would try 20% fan for ABS.