1 Topic by dave.lantz

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Topic: Hollow bodies???

Well I am beginning to understand why 3D printers aren't readily available at Staples! LOL

OK guys I tried to read up as much as possible but after half a day I'm lost and I know one of you has the answer.

I tried a simple experiment on a small part and I cant get it to work no matter what I try.

Tried to make a hollow cone for the back of a blowgun dart. See attached.

No matter how I slice it in SlicR or Skeinforge it comes out as a solid in g-code. WHY?

What trick am I missing here? (and BTW, you shouldn't need a trick to accomplish this - if the model has openings then so should the g-code)

Thanks as always!

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Dart Cone.stl 105.05 kb, 24 downloads since 2014-04-11 

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2 Reply by wardjr

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Re: Hollow bodies???

Hey Dave,
First off I am having a hard time making that file manifold.
Second when you do a part like that you want to print it solid infill set to one.  You only need a couple of perimeters.
By solid I mean the walls are solid.  I have a meeting in a few minutes but if you can wait for a few hours I'll be happy to help you through the process.  In the mean time send or post a link to the .skp file.  It is always the simple things that seem to be the hardest.

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3 Reply by dave.lantz

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Re: Hollow bodies???

Thanks so much Ward! I will attach the .skp file here.

I do not understand what you mean when you say "manifold". Can you point me to an explanation and a tool?

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Dart Cone.skp 34.06 kb, 7 downloads since 2014-04-11 

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4 Reply by wardjr

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Re: Hollow bodies???

dave.lantz wrote:

Thanks so much Ward! I will attach the .skp file here.

I do not understand what you mean when you say "manifold". Can you point me to an explanation and a tool?

So manifold means will it hold water or is it water tight.  When you look into the cone of the .skp notice how it is darker gray instead of white?  That is not manifold.  In essence the geometry doesn't add up.  I will quick try and fix it and send it back to show you what I mean.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

5 Reply by wardjr

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Re: Hollow bodies???

So in this case the narrowest portion of the cone on the inside wall meets the outside wall.  Basically it had no thickness to it.
So pay attention to the inside and how I connected the lines and all surfaces are now white.  I did run it through netfabb when I was done just to fix where the cone meets the cylinder. 
I included the printable .stl and the .skp so you can see the corrections I made.

Also.... I can't emphasize this enough...It is much easier and precise to design in mm's.  So if you can't figure out how to get your software to understand mm's let me know and I'll help you through that process also.

Hope this helps.

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Dart Cone.skp 60.52 kb, 1 downloads since 2014-04-11 

Dart Coneuntitled (repaired).stl 25.28 kb, 9 downloads since 2014-04-11 

You don't have the permssions to download the attachments of this post.
Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

6 Reply by dave.lantz

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Re: Hollow bodies???

Thanks a bunch Ward. I haven't designed in metric since college but I guess I'm going to have to learn again big_smile

I do understand what you mean by manifold now and I tried to do that but SketchUp (free version) isn't always easy to see that or manipulate it to do it. I'm a SketchUp semi-Newb. I was pushing and pulling edges to seal it up but I guess i didn't succeed.

Anyway, I sincerely appreciate all you help!

Dave

7 Reply by wardjr

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Re: Hollow bodies???

I try and avoid push pull at all costs.  It is almost guaranteed that it will mess with the geometry.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

8 Reply by michael.t.albers

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Re: Hollow bodies???

good work wardjr.  I have to agree with him, work in mm's.  It will become second nature after a few times, but it really makes trouble shooting a lot easier.  digital calipers usually have two settings, sae and metric, and just pushing a button on them can get you quick conversions.

9 Reply by MeshMoth

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Re: Hollow bodies???

...I was bored so i re-did the file instead of repair it.

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Dart thing.stl 104.48 kb, 10 downloads since 2014-04-17 

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