Raft/Support material?

I've been using Skeinforge for a while and for the heck of it I gave this Slic3r a try and it did an amazing job at .05mm layer height the first time.

I noticed there is a check box for support structure. I turned it on and selected Primary then loaded one of my models and it didn't make any support... Am I doing something wrong? I didn't see any other settings for support. I figured it would just work. And whether or not this object needs support, yeah it's basically a sphere shape so it doesn't really make contact with any flat surface.

And I didn't see an option for raft? I can understand you don't need a raft most of the time but in some rare cases like this where there is a tiny amount of contact on the platform you really need it. Or at least a support structure under the entire model.

Love the program so far!

I'm having the same issue. They just added support in this version of Slic3r, which was released 3 days ago, so it's probably just a bug that will be fixed soon.

Also, thanks to the devs for all the good work on Slic3r. It's the best slicing program I've used yet.

Edited 1 time(s). Last edit at 02/29/2012 09:24PM by gtg252b.

With a proper heated, level build bed, rafts isn't and shouldn't be necessary. With tiny parts, and the rare occasions where it's needed, add a base to the model manually.

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-Nudel
Blog with RepRap Comic

Nudel, I think he was complaining more it not actually adding support when you check the support checkbox. Are you getting support when you set this parameter?

Ah, must've misread that, sorry.

But yes, I do get support for angles close to ~80-90 degrees.

Try out this openscad snippet to see it generating support. Not useful to print, but you get the idea.

for(i=[1:19]) rotate([i*18/4,0,0]) translate([15*i,0,0]) cube([10,10,50]);

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-Nudel
Blog with RepRap Comic

Interesting. I get support with that structure (for the two steepest cases), but I have some files that have 90-deg overhangs that aren't getting any support when I slice them. For comparison, I tried this case (http://www.thingiverse.com/thing:11637), and I get no support. I guess the support algorithm just needs a little more tweaking.

Yeah I'm not getting any support. for example I have a character with arms hanging down and it's not making any support structure with the option turned on. I'd also like to have the support be made for an entire object that is floating (mainly because it has no flat spots like a sphere).

Any word on the Support not working?
My simplest test case 3mm walls, 10mm hi, 10mm deep, 20mm wide,

cube([3,10,11]); 	// left
translate([20,0,0]) cube([3,10,11]);  // right
translate([0,0, 10]) cube([23,10,3]);  // top



  +==========+
  |          |
  |          |
  |          |

Not a very good example, as that bridge is no problem to print without support structure, and I would assume Slic3r takes that into account.

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-Nudel
Blog with RepRap Comic

Keep on increasing the width - the support does not kick in, but the sag does..

Of course, but I don't think the support-detection math is that mature yet, as it has only just been introduced. Think of it as a beta feature, give it some time and it will become more advanced.

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-Nudel
Blog with RepRap Comic

Whether bridges are supported or not is really a user preference. I think commercial machines always support any overhang because that gives the best quality. For functional parts, where aesthetic don't matter, it is much quicker and cheaper to leave it as a bridge and perhaps remove some loose filaments that hang down to clean up the part.

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[www.hydraraptor.blogspot.com]

Oh well - it's made me try something I've been meaning to do fo a while, a parameterised "Support Pillar" in OpenSCAD
Works perfectly - no sag under the bridge. The pillars are hollow 2mm square.



The intention was for the triangular top pieces to each be a single 0.5mm thick sheet, but with anything less than 1.5mm thickness slic3r produces gcode that visualises looking like a moth has nibbled most of the sheet away - leaving little bits here and there suspended in nothingness.

Edited 1 time(s). Last edit at 03/04/2012 05:21PM by nb99.