Pinch wheel extruder -> Art of Illusion help!

to any AoI experts out there, here's a question for you:

I want to print Adrian's pinch wheel extruder, but I need to convert it to an STL first, and perhaps check that the bolt patterns match the splined steppers I've found. I've got AOI 2.72 loaded up (tried it on a Mac and Linux so far), with all the scripts and plugins as per the AOI hints page, but I'm still getting errors when I try to load the pinch-wheel-extruder.aoi file (revision 2743)from Sourceforge. Here's the errors:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
at artofillusion.object.TriangleMesh.setShape(TriangleMesh.java:536)
at artofillusion.object.TriangleMesh.(TriangleMesh.java:268)
at artofillusion.object.CSGModeller.getMesh(CSGModeller.java:275)
at artofillusion.object.CSGObject.convertToTriangleMesh(CSGObject.java:233)
at artofillusion.object.CSGObject.cacheMeshes(CSGObject.java:296)
at artofillusion.object.CSGObject.getWireframeMesh(CSGObject.java:288)
at artofillusion.object.CSGObject.findBounds(CSGObject.java:155)
at artofillusion.object.CSGObject.getBounds(CSGObject.java:137)
at artofillusion.object.ObjectInfo.getBounds(ObjectInfo.java:349)

Any obvious things I'm missing here?

Wade

Hi Wade,
I am not an AOI expert. I just tried opening that file with AOI v2.7.1 on XP, and I get exactly the same error.

Most things I try to do in AOI end in a non-manifold mesh and trying to fix it generally results in an out of bounds exception. I don't understand how anybody manages to use it.

Chris

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[www.hydraraptor.blogspot.com]

Yes, I feel the same way about AOI, but if I need to change the bolt hole spacing, I'd rather do it in AOI than re-build the part in Co-Create or Blender. Of course, I think I've already passed the point where I've spent more time messing with AOI than it would have taken me to just re-build the part in some other format.

The problem is that without AOI loading the part, I can't even check the dimensions to rebuild it. I guess I can just eyeball it from the photos, but that kind of defeats the purpose of all this design sharing that's going around at the moment.

Any other ideas?

Would somebody give me a link to that AoI file. I've had a lot of experience with AoI and know many of it's little ways. Who knows, maybe I can crack that? :-)

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Never mind. Found it.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Interesting. Adrian saved it as a gz zipped file. I unzipped it and found that it didn't have an .aoi suffix on the end so I put one on and AoI wouldn't cope. I then just asked AoI to open the gz file and it worked fine.

Just in case that is too much for anybody, I saved it back as an .aoi file and put that in a zipped file {.zip}. You can access it here...

www.3dreplicators.com/New Front Page/Documentation/CAD/Pinch wheel.zip

Edited 1 time(s). Last edit at 05/22/2009 09:39PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Where did you find the gz file. I got the AOI from SVN and it did have the .aoi suffix.

I down loaded your zip but it gives the same exception. Also it is the NEMA14 version and I assume Wade wanted the NEMA17 one.

Which version of AOI are you using? Perhaps you and Adrian are using an older version and this is a new bug.

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[www.hydraraptor.blogspot.com]

It looks like it IS a new bug. I have version 2.7. Looking on the website I see that they've had 2.7.2 since April. Mine dates from January.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Oh well, so much for that idea. I downloaded and installed version 2.7.2, the most current one on another drive.

I then tried to open the NEMA-14 pinch wheel extruder.aoi file and it opened just fine.

Wait a minute, I'm using the windows version. Which one are you guys using?

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

I am using the Windows version on XP and Wade reported it on Linux and Mac, so it's a mystery. I can't open either of them from SVN or your copy.

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[www.hydraraptor.blogspot.com]

That's really creepy.

Maybe AoI recognises users who don't really like to use it and behaves accordingly.

Just so you won't think I'm pulling your chain about this, here is a screen grab of the NEMA-14 pinch wheel extruder.



I'll tell you what. Let's not go crazy with this. I assume that Wade wants STL's of the pieces of the pinch wheel extruder. If somebody will give me a link so that I can download the proper NEMA-17 .aoi file, I will be happy to save the parts as STLs on my system and upload them here.

Will that help?

Edited 5 time(s). Last edit at 05/23/2009 11:31AM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

There is a bug report for an out of bounds error in the last two versions by wizard23, are you sure you are running 2.7.2?

[sourceforge.net]

Edited 1 time(s). Last edit at 05/23/2009 11:33AM by nophead.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
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> are you sure
> you are running 2.7.2?
>
Yup.



Edited 1 time(s). Last edit at 05/23/2009 12:18PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Finally found the NEMA-17 version of this extruder after cleaning my reading glasses.

Edited 2 time(s). Last edit at 05/23/2009 12:20PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Okay, here are the STLs for the NEMA-17 (revision 2743) pinch wheel extruder.

NEMA-17PinchwheelextruderSTLs.zip

I can't for the life me not tell what the difference between the Base Block and the Base Block Strip is. You might want to ask Adrian about that.

Otherwise, have fun!

Edited 1 time(s). Last edit at 05/23/2009 03:49PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

nophead Wrote:
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> Where did you find the gz file. I got the AOI from
> SVN and it did have the .aoi suffix.
>

Sorry, missed this earlier... Here is the link for the NEMA-17 GZ file

[reprap.svn.sourceforge.net]

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

Forrest and Nophead, thanks tons for the STL's and all the help! Sorry I didn't respond earlier, had a few too many beer with the neighbors last night...

I just tried booting a version of Windows XP that I haven't used for a while, and it had AoI version 2.6.1 loaded up, which loads both of those files without complaint. Here's the link I was using, just for reference:

[reprap.svn.sourceforge.net]

Will try upgrading to 2.7.2 and see if it still works on XP.

Wade

Interesting - upgrading to 2.7.2 on Windows XP without the plugins causes AOI to hang when I open those files, but after I install all the plugins (excluding the alphas), I'm back to the same original error:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
at artofillusion.object.TriangleMesh.setShape(TriangleMesh.java:536)
at artofillusion.object.TriangleMesh.(TriangleMesh.java:268)
at artofillusion.object.CSGModeller.getMesh(CSGModeller.java:275)
at artofillusion.object.CSGObject.convertToTriangleMesh(CSGObject.java:233)
at artofillusion.object.CSGObject.cacheMeshes(CSGObject.java:296)
at artofillusion.object.CSGObject.getWireframeMesh(CSGObject.java:288)
at artofillusion.object.CSGObject.findBounds(CSGObject.java:155)
at artofillusion.object.CSGObject.getBounds(CSGObject.java:137)
at artofillusion.object.ObjectInfo.getBounds(ObjectInfo.java:349)



Reported 4 time(s).

Hm, maybe I just need to downgrade to an earlier version for now. I've been running MacOSX, Linux and WinXP on the same Macbook; perhaps it'll work on my old Windows laptop - might be a video card issue.

Wade

Wade,

Quite some time ago, I found that OpenGL was fighting with AoI in an early version. Disabling it put things right. I don't know how it is now, but OpenGL and ATI technogy video cards weren't a happy couple. That may be all changed by now, but then I've had Nvidia cards for the last two PC's that I've bought so I wouldn't know.

All the best,

Forrest

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

OK, downgrading to AoI 2.7 on MaxOSX works as well, on both video cards (Nvidia 9600M and 9400M), so everything is good. Not sure why 2.7.2 works for you Forrest and not for me; perhaps there are some Java libraries that I'm missing? Either way, I'm good to go now. Thanks!

Wade

I wonder if it's the Java. I haven't upgraded my Java in a while and, as you can see in my screen grab of the version number for AoI, am using Java 1.6.0_13. Are you using a later version?

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

We also had some issues with 2.7.2 being less stable than 2.7 wrt. boolean operations. Otoh, 2.7.2 evaluates the boolean objects significantly faster.

I haven't pinpointed the problem yet, but if someone manages to isolate this problem to a simple test model and submit it to the Art of Illusion team it would be awesome!

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~/= Marius

--
We are Elektropeople for a better living.
[reprap.soup.io]
[www.metalab.at]

I'm actually using an older Java version on the Mac - 1.5.0_16

beeblebrox:~ wbortz$ java -version
java version "1.5.0_16"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_16-b06-284)
Java HotSpot(TM) Client VM (build 1.5.0_16-133, mixed mode, sharing)
beeblebrox:~ wbortz$

On Windows XP, I'm using 1.6, but an older version than you Forrest:

C:\>java -version
java version "1.6.0_07"
Java(TM) SE Runtime Environment (build 1.6.0_07-b06)
Java HotSpot(TM) Client VM (build 10.0-b23, mixed mode)

Neither of those versions would load those files in AoI 2.7.2, but they seem to work fine with 2.7.

Wade

edit - forgot to mention that turning off OpenGL in the AOI preferences didn't help AOI 2.7.2

Edited 1 time(s). Last edit at 05/23/2009 02:40PM by Wade Bortz.

Marius,
I don't know if it is related but I did isolate a fundamental bug in the boolean operations a long time ago: [sourceforge.net]

It got closed as fixed but it wasn't last time I tried it it on 2.7.1, so I re-posted it. With such a fundamental bug I can't see how anything works, and indeed in my experience nothing does. I also verified with Vik that he got the same bug, on a different OS I think.

However, you, Philipp, Forrest and Enrique seem to be able to do wonderful things with it, so perhaps it does behave differently on different systems for some reason. Odd to get array index problems on different versions of Java though, if it is the Java that is making the difference. I tend to be on the latest Java because it auto updates very frequently.

Maybe it is down to plug in combination / versions. Did Adrian use your CSG evaluator to model the pinch wheel extruder? Would that affect the saved AOI in a way that makes it only work if you have your plugin when loading it?

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[www.hydraraptor.blogspot.com]

In my experience, boolean ops in AoI definitely has problems. After a while, however, you begin to get a feel for what triggers them and learn to avoid doing things like that. I've not found it too debilitating a limitation. In my experience, all tools have quirks. AoI certainly has its share.

Most of the creepy things that I've seen the boolean ops do can be avoided by being careful not to get surfaces on exactly the same plane overlapping each other. Intersecting on different planes is fine. Overlapping sometimes causes serious problems. As a practical matter what that means is that you need to avoid building up a complex shape as a bunch of small pieces. You have much better luck if you start with a big piece and use properly shaped solids to cut it down. I noticed in the NEMA-17 example that Adrian does just that.

As well, all kinds of grief can happen if you do a boolean op before you've converted the two solids to a triangle mesh first. It's not that the op won't happen and look right, but when you finally get around to converting it to a mesh it can make a real mess of your final product when you try to save it to STL. It is also a good idea when you have created a boolean product on the way to making a complex shape that you pull it into edit mode and take a look at where the mesh nodes are and check to see that their layout isn't too crazy. I tend to use the "simplify mesh" option regularly when I am in the process of creating a complex shape. Complex for me, means using 5-6 solids, not 20-30. You have to watch the simplify operation. It can screw up your mesh if you use the wrong settings or apply it indiscretely.

AoI can be made to work. It just requires a bit of care and consideration.

Edited 1 time(s). Last edit at 05/23/2009 07:41PM by Forrest Higgs.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison

On the other hand, converting to a triangle mesh is *really bad* for anyone trying to go back and figure out what you have drawn, or modify it. Please don't do it if you can avoid it.

> Maybe it is down to plug in combination /
> versions. Did Adrian use your CSG evaluator to
> model the pinch wheel extruder? Would that affect
> the saved AOI in a way that makes it only work if
> you have your plugin when loading it?

We dont store any additional plugin information in the aoi file.however after investigating this yesterday we found that we dont center the objects before the csg operation. there will be an updated version ofthe CSG plugin soon

nonetheless the csg code in aoi 2.7.1 and 2.7.2 seems to have degraded. Using the problematic part in the pinchwheelextruder (the ball race object makes it fail) I created a much simpler test case (than the one i uploaded before) that demonstrates the new csg bug in the newer AoI versions: [sourceforge.net]

I dont know if anybody reads these bugreports though...

For a quick fix either just delete the "ball race" object (what you can do even without seeing the object by selecting in in the tree view) or just use AoI 2.7.

wizard23 Wrote:
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>
> I dont know if anybody reads these bugreports
> though...
>
They're really good about reading bug reports.

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Hell, there are no rules here - we're trying to accomplish something.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

Thomas A. Edison