AoI Alternatives

Hi Forrest,


Forrest Higgs Wrote:
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> ...
> Is there a question here?

... it was a kind of brainstorming with an alternative construction-strategy that would be similar to the fabrication and maybe meet better the reprap way?

- Instead of thinking and assembling in the common way, where you construct a box in the size of your desired object and start to cut away holes, throughputs and free volumes ...

- Why not start with a big magazine of predefined shapes and blocks in the height of a single layer or a factor of them?

Then the object wouldn't be a set of 3D-points with triangles between them, but an array-list of defined shapes per layer, so the slicing will be much simpler, then calculating a cut through the aligned surfaces.

When this layering would be already part of the designing process, then you have a total different way of designing, constructing and reprapping your parts - similar to build complex objects out from lego-bricks ...

Viktor

Sounds interesting! Are you going to have a go at it?

Kyle Corbitt Wrote:
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> But I'm still curious what you see as the problem
> with Alibre Design Xpress, which is crippled
> compared to the full version but will design
> individual components just fine and outclasses AoI
> on nearly every front.

I've got no problem with it at all, if it in fact is as capable as you say it is. How many hours experience have you got on Alibre Express and AoI do you have on which to base that judgement? How many objects have you designed?

Forrest Higgs Wrote:
-------------------------------------------------------
> Sounds interesting! Are you going to have a go at
> it?

yes, i want to make some experiments with layered fabbing with lasercutted plastic- and paper-sheets in plane and on cylindrical surfaces and this kind of designing would help a lot.

But actually i didn't have much time for this - today i finally managed to mix one of Fernandos UV-curing receipes (which i promised making in April!), but over the weekend i'm offhouse again, so this have to wait some time more ...

Viktor

Lego designer is free (but not open source?) and easy to use.
It would be interesting to get STL files out of it, but I had a quick google and didnt find anything.
The build-from-layers-on-a-baseboard is a good starting point for future non-engineer reprappers.
Pro-Engineer (also closed etc) is available for

Edited 1 time(s). Last edit at 07/04/2008 04:27PM by Richard Benjamin.

Here's a constructive Idea:

I agree with the instinct to cling to open source, although nothing open source currently matches professional software (even for our simple uses).

How about setting up a fund with the people from AoI (or just us) to solve the problems in the software.

it would be like the millennium problems, just for RepRap and AoI.

(http://www.claymath.org/millennium/)

the fund would be supported from donations and perhaps sales from the RRRF.

sitting at the sidelines waiting for stuff to get better is not my type of game.

-Leav

That's a proposal that you should be putting before the board of the RRRF. Frankly, I haven't had much trouble getting the attention of the AoI people simply by posting the problems I had on their forums. They've been pretty good about bug fixing. Mind, getting them to turn AoI into another Inventor might well be a bit more than they want to take on for love or money.

If you insist on a more "engineering" sensitive 3D Cad package I'd strongly suggest that you download and work with the current version of Blender. You'll find it more familiar than AoI and it has a wealth of tutorials that you can access merely by googling +Blender +CAD. For instance...

[www.blender.org]

Blender is written in Python, apparently, which means that it should execute a LOT faster than AoI which is written in Java, which imo was a pathetic attempt by C freaks to exact revenge on the world for not falling in love with their language.

Most of the "discussion" I've seen on this thread amounts to people who are already using some other commercial CAD package bitching that AoI isn't up to the standards that they're used to. Well, tough. You can use ANY CAD package that can generate STL files with both Darwin and Tommelise. Most folks haven't got several thousand dollars to plunk down for a professional CAD package just as they haven't got several tens of thousands of dollars to plunk down on a commercial prototyping machine. If they did they wouldn't be here trying to build a Darwin or similar. This is reality, Fred. Get used to it.

Leav Wrote:
-------------------------------------------------------
> Here's a constructive Idea:
>
> I agree with the instinct to cling to open source...
...
> sitting at the sidelines waiting for stuff to get
> better is not my type of game.
>
> -Leav

I agree with Leav's sentiment completely!

One aspect that seems to be missing in this discussion is the libre (see gratis vs. libre [en.wikipedia.org] ) aspect of using open source software. While much of this discussion has been about the monetary cost of advocating various commercial packages, I am also interested in the social benefits of a full open-source toolchain for home manufacturing.

Going with open source software provides a sort of community insurance policy not available with commercial software. As more designs are posted in the RepRap object library ( [objects.reprap.org] ), the ability for others to use and edit these objects becomes more important. While the STL file format can represent a mesh, it does not hold all of the information useful for editing objects (hence the .aoi files). Saving this information in a proprietary format can make it less accessible to the community as a whole and potentially make it unreadable in the future (when that company goes out of business or no longer offers low-cost versions of the software for download). Using open source software ensures that a model made now will likely always be readable. Furthermore, if a new, more popular, open source program arrives in ten years, the source code and open specification of both could be used to easily convert designs from one format to another.

Granted, AOI can be a bit cumbersome for some mechanical modeling tasks. The beauty of open source software, however, is that it can be modified and improved by the community. As our needs change, we are free to modify the software to meet those needs. If AOI doesn't quite do what we want yet, let's add the features we desire, and make the result available for the benefit of all.

This may seem scary, or like a lot of work to a lot of us RepRappers. I postulate that those of us most attracted to the RepRap project are the mechanically inclined, the ones who prefer to tinker and build things in the physical realm. The idea of modifying software or adding features may seem foreign and scary because it's not what some of us naturally do. With help from those that like to tinker in the digital domain, the thought of adding AOI features might not be so daunting.

One of the most exciting aspects of the RepRap project, for me, is the fact that it is managed in the Open Source spirit. The machine and the objects designed to be made for it are encouraged to be published in open formats and for the entire world to benefit from. Let's keep with this spirit of openness, generosity, and accessibility, and think about what specific features we would like to add to an open source modeling package, and how they should be implemented.

I found this project yesterday:
avoCADo - [avocado-cad.sourceforge.net]
It's in the very early stages of development at the moment, and I was only able to make a couple of cubes, but their goals seem to be very similar (pretty much the same) as our requirements. The projects seems alive and being worked on, the last update was posted in March.

Also, re ldraw and mlcad: I used them many years ago, mlcad is a pretty good cad package and is very intuative, I never tried to make any complex shapes from scratch though, only really used existing lego blocks. As far as i remember, mlcad is a frontend for ldraw

avoCADo... hmmm... at the very least, I like the name!

Now this sounds promising!

read the vision: [avocado-cad.sourceforge.net]

I'll shoot them an e-mail - it would be cool if they could integrate RepRap into their design intent.

@Forrest this ties in to what you were saying: I'm sure AoI's community would not be thrilled about us wanting to take AoI into a new direction.
avoCADo on the other hand... they just might be our soul mate!

-Leav

EDIT
I opened up avoCADo and was pleasantly surprised! the interface is amazing and it seems to be taking it's first steps into the big world of CAD!
I managed to create extruded shapes, revolved features and extruded cuts.

I think even Forrest will be impressed with it

Now it just needs to get developed!

I shot the developer an e-mail, inviting him to take part in a discussion on this forum (not this discussion...) where he could get to know the project and what we need out of a CAD program and he could see if there is anything that is new to him or maybe even try and recruit some people here to help him (if there are any programmers here)

-Leav

Edited 1 time(s). Last edit at 07/05/2008 06:54PM by Leav.

They are going for a simple easy to use interface a bit like aoi. I found it a few days ago, but held of posting until i had properly checked it out.

I thought you would like it forest

This page shows their priority of work:
[avocado-cad.sourceforge.net]

I'm almost tempted to do a little work on it myself, although i would have to learn java first

Going to the site, I note that it is...

avoCADo-08.03-preAlpha

This puppy is a long, long way from prime time. It may be wonderful ... some day.

yeah you can't even save right now... but it is the only CAD program out there being developed to do exactly what we need. it would be a shame to let it struggle all on it's own....

I don't know about the avaCADo developers, but I know once people show and interest in some software, it encourages me to find more time to work on it. I checked out the source code and tried to build it for scratch, but i'm getting a few errors, but i know nothing about java yet so thats unsurprising.

Greenarrow: I agree. even just knowing that he has a big user base waiting for updates could really motivate the developer.

-Leav

Leav Wrote:
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> Greenarrow: I agree. even just knowing that he has
> a big user base waiting for updates could really
> motivate the developer.

To do what? For free? I gather there is only one of him with everybody else just standing on the sidelines cheering him on. I've been in that situation all to often to think that it will get us what we say we need. If we had half a dozen propeller heads in Reprap that would jump in and lend him a hand it would be a very different matter, but I frankly don't see that happening, do you?

BTW, I went through the Blender tutorials last night and this morning. You may be interested in what I found out.

[www.3dreplicators.com]

>>To do what? For free? I gather there is only one of him with everybody else
>>just standing on the sidelines cheering him on. I've been in that situation all
>>to often to think that it will get us what we say we need. If we had half a
>>dozen propeller heads in Reprap that would jump in and lend him a hand it would
>>be a very different matter, but I frankly don't see that happening, do you?
what's with the negativity man?

nice blog post...

all i'm saying is that it can't hurt: it might bring RepRappers to his side, it might give him a boost to get the software to a point where other unrelated (i.e. non RepRap) people will jump aboard.... it's positive all the way around.

i'm thinking ahead. in 2 years, do you still want to be using AoI or Blender? or something more like what avoCADo can be in a couple of years of good development?

forget about moving now... what about down the road?

-Leav

Leav Wrote:
-------------------------------------------------------
> in 2 years, do you still want
> to be using AoI or Blender? or something more like
> what avoCADo can be in a couple of years of good
> development?
>
> forget about moving now... what about down the
> road?

My main focus right now is on 3D printer development. 3D modeling is something that I did for 30-odd years and am not excited about doing again. Two years ago, AoI and Blender were nothing like they are now. In another two years, I doubt we'd be able to recognise what they'll become.

If AvoCADo really fits the bill in two years I'll grab it with no reservations. Everything, however, will have changed in that amount of time.

Forrest Higgs Wrote:
-------------------------------------------------------

> My main focus right now is on 3D printer
> development. 3D modeling is something that I did
> for 30-odd years and am not excited about doing
> again. Two years ago, AoI and Blender were
> nothing like they are now. In another two years,
> I doubt we'd be able to recognise what they'll
> become.
>
> If AvoCADo really fits the bill in two years I'll
> grab it with no reservations. Everything,
> however, will have changed in that amount of time.

My main focus right now is building a darwin.. (not even development... just copying at this point! )

buy I agree completely. it's just that I think that if we are going to look down the line i'd rather have a software designed for engineering CAD rather than creating vaguely disturbing movies about giant bunnies

Basically what i'm saying is that we should believe in the power of the IDEA of RepRap to motivate developers towards avoCADo because I believe RepRap needs an engineering oriented CAD.

Motivating the development of avoCADo (or any other engineering CAD program) should be a mission priority for RepRap, on the list with a support extruder and replacing more and more parts with RepRapped parts.

it's a slow process but if no one ever starts it it will never happen.

---------------------------------------------------------------------------

now I want to touch on a related matter:
I'm new here, and I realize that I know very little about RepRap as a movement and foundation, but I think that voicing my opinions so assertively should be welcomed because even though I'm not a RepRap Guru yet, I am still a person that is fairly intelligent and can give the experienced team a new outlook on things.

I hope that's ok with you guys because if it isn't.... tough luck for you!

-Leav

Leav Wrote:
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> i'd
> rather have a software designed for engineering
> CAD rather than creating vaguely disturbing movies
> about giant bunnies

Good one!

No giant bunnies here :
[code.google.com]

but not much else either - but it seems to be a current active project for engineering 3D CAD.

Thank you very much for this link!
Im reading through the blog posts from may, and it is really impressive how far he got in just two months!

Yes for us (hobby-engineers), we need a 3d modelling tool, which is not a mesh editing software (google sketchup, blender, wings3d, aoi, etc), where circles are perfect, cylinders are cylinders and not meshes.

And for us, all we need is just modelling. No rendering, no animation, no game-engine. Just modelling, pure modelling.

I keep an eye on this wildcat project!

(sadly there is no linux version yet)

Re: Blender...

A guy just posted a link to tutorials for high precision devices using Blender over on my blog. Check out the tutorials...

[www.rab3d.com]

and the gallery that you can link to from there. It's pretty mind-blowing. It appears that giant rabbits aren't the only thing you can do with Blender.

See also

*Blender ProCAD (Snaps, chamfer, fillet, etc.) Italian documentation, some english
[blenderartists.org]
[www.aleppax.it]
[www.blender.it]

*Blender Caliper
[blenderartists.org]
[www.alienhelpdesk.com]
[www.allanbrito.com]

Note that the links and discussions above may go to old versions. You may need to research a bit to find the newest version or the current documentaion.

*Lengthen - a script to specify a precise distance between two points
[www.allanbrito.com]

*Geom tool
[www.allanbrito.com]

Edited 1 time(s). Last edit at 07/09/2008 02:52AM by SebastienBailard.

RepRap doesn't need to pick the one true CAD platform. The ideal solution is for RepRap to support multiple tool paths. Anything that makes .stl files or .pov files or gcode files should be usable.

I personally detest stl. It's the lowest common denominator of ignorance. Terrible to manipulate but easy to parse. Those of you that like generating stl files in AoI should keep at it. But those of us who can't stand AoI and stl will have options too.

A lot of objects can be described as math and commands. Some of us would prefer tools that let us write source code rather than draw pictures. And I think reprap will eventually support those tools to some degree.

James,

You are completely correct, of course, but I think you are missing the point a bit... (or at the very least you are missing what I consider being the point )

The question is of standardization. RepRap needs to have a viable CAD solution in order to really succeed.

I'm guessing that a lot of people will chosse to use professional tools they can get for a bargain from their work or school (i.e. SolidWorks, pro/E, Inventor, Rhino.....), but Mr. Joe RepRapper from Iowa needs something to design his replacement sifter for his seed distributor in, and he doesn't get those things for free (and he can't code in PoVRay ).

Without a standard software solution for RepRap, Releasing it to the the public is tantamount to releasing the cartesian bot without motors and letting people decide which motor they want to use and figure out how to make it fit the frame and the software.

-Leav

I think (and this is not an entirely original sentiment) that for the moment, at least, the bigger issue is a standardized file format. Using something obscure like AOI's native format has in practice many of the same problems as a proprietary format, insofar as it's unlikely that anything but AOI will be able to handle it. Instead, perhaps we should focus on choosing (or creating!e) a format capable of recording all the data necessary for lossless interchange of modifiable designs, describing objects in terms of volumes and smooth surfaces instead of vertexes and faces, perhaps even with room for expansion with information like material type. Even if this format turns out to be just as obscure as AOI, having such a flexible format would be well worth the time and effort necessary to write conversion software for whatever CAD package(s) the community standardizes on.

This in mind, I realize it's still important to have a free and open tool that's practical to work with, ideally for users with needs and skills ranging from those of a casual home user to an engineer or scientist building or maintaining complex and unique machinery. While a well-selected file format or a major effort to write converters would allow most people to use whatever tool they themselves prefer, a single "standard" tool is a good idea, as it would make it simpler to put together a standardized all-in-one package, and make it easier for the community to provide support to all manner of users in all stages of the process.

In the course of this discussion, it's been asserted that there simply is no free and open professional-quality CAD software out there. This is false. I present to you BRL-CAD ( [brlcad.org] ), a package which has been proven through (and actively developed across) more than twenty years of use by the U.S. military and various other industrial customers. It's portable across countless platforms (probably even more than the java VM itself is), its codebase having evolved this way out of necessity as the operating systems and hardware of twenty years came and went. It's extremely unlikely to become unsupported, and its long history of use makes its power and effectiveness unarguable. The only issue that remains is usability. Software for trained professional use tends to be of arcane interface, as does software of great history; BRL-CAD is both, and its user interface makes this painfully clear. However, the user interface is far from the most complex part of a professional CAD system; while some have suggested we support and contribute to the improvement of the functionality of packages such as AOI and Blender, which both sport user interfaces far more friendly than BRL-CAD, as CAD systems, I instead propose that we support the development of a user-friendly interface for BRL-CAD's modelling package. This would require a minimum of work and offer access to a system which may well exceed the capabilities of even the most elaborate modern competitor.

Edit: Who doesn't like a good visual example of a program's capabilities? Click for awesomeness: [brlcad.org]
Edit 2: I should also state that, while arcane, BRL-CAD has *VERY* extensive and apparently high-quality documentation [brlcad.org] . The Introduction to MGED pdf alone is almost 300 pages of clear, readable tutorial text which doesn't seem to assume much knowledge on the part of the reader.
Edit 3: A visit to #brlcad on irc.freenode.net shows me that there is in fact an existing and very active development effort to produce a user-friendly interface: [brlcad.org]

Disclaimer: I'm not actually intensely familiar with BRL-CAD's functionality; however, a perusal of their web page shows a very impressive resume.

Also, a note to Forest: Blender is written in C/C++. Python is supported as a scripting language, but not terribly well, as the Blender/python interface tends to fall out of date with respect to Blender while still having been developed beyond that which is documented. Also, most C programmers intensely dislike Java, as it takes a very different (and often badly performing) approach to programming, as similar as some of its syntax may be.

Edited 3 time(s). Last edit at 07/11/2008 02:27AM by Ralith.

... i have similar problems, discussions, thoughts and workarounds for making 3D-Objects on my CNC-mill, but milling is much more common, older and therefore mature then reprapping.

I have a fully capable 3D-CAD/CAM-program with my CNC-mill, but dependant of the object (or the source i received predefined ones) i'll go different ways:
- for simpler 2D- and 3D-parts i'll work in the proprietary mill-CAD/CAM
- complex 2D-shapes are designed in Corel, exported as DXF and finished in the CAD/CAM
- complex 3D-objects are designed in Lightwave (V7, many years old and 'outweared'), exported as STL and finished in the mill-CAD/CAM.
- some predefined 3DS-sources are manipulated in (old too, V7) 3DS-Max, exported as STL ...
- other predefined 3D-objects (STL, 3DS, LWO, OBJ, ...) are imported and manipulated in Lightwave, Max or sometimes other 3D-programs i have laying around or testing, but Lightwave is more common for me, so i used it most the time.

I had some testing with Moray/POV-Ray, BRL-Cad, Blender, Maya-SE, Cinema4D, Amapi, O2C-Composer and much more 3D-programs, but it wasn't so much easier, so i'll stay with Lightwave.

I think everyone has his own learning-path, dependant of the computer and OS he use or the programs he can lay hands on.

As the reprap is more a backend and finishing tool (as the CNC-mill), it's main task should be importing and outputting some common 3D-formats, maybe some optimisation as materials-per-parts and calculating supports to fulfill its job.

For the designing of 3D-objects you can use any software, you have at hand, but the typical user won't construct his own 3D-objects, but get some ready predefined from a repository, from some objkect-galleries or ask a friend - then make some adjustment and press the 'fab'-button ...

And here you should take a look in the world of 3D-CNC-milling, as most problems and solutions are nearly the same and had some decades of time already to settle ...

Viktor

PS: here [brlcad.org] is a good description of 3D-converting-issues

Edited 1 time(s). Last edit at 07/11/2008 05:02AM by Viktor.

The only problem I can really see floating around with BRL-CAD is that so far as I can tell there are no macro-like mechanisms in it - you can't, for instance, make a feature, then /define/ a pattern, and have that feature repeated in that pattern and be able to edit the definition of either the feature or the pattern without having to manually repeat each step since the change. I would be delighted to find out that I am mistaken, and am probably going to pursue that feature in any case - it seems like it wouldn't be too bad to add, even though to do it the way I'd like requires building some kind of scripting language into at least the editor.

I was going to comment that putting together a more user-friendly interface is a good idea, but apparently it's already in progress; I'll stick with the current one (comfortably vim/ex-ish and I like steep learning curves), but it'd be nice to have one to recommend to other people.