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CAD Standards Group
  • To all CAD designers:

    It is the purpose of design work to produce clear and easy to understand drawings. In order to accomplish this goal there are several decisions that need to be made and adhered to for all drawings to ensure universal comprehension of the drawings.

    Issues to be addressed:
    -standard file formats, development of standard design tools (software)
    -Standard dimensioning standards such as units and typical number of decimal points.
    -training and implementation of GD&T standards
    -Standard title block, part naming conventions, and change process.

    All CAD designers need to participate in the discussion and the final deliverable will a certification curriculum and process to ensure a common language for design so we can focus our creativity on designing and not on arguing about how to dimension a nut or washer.
  • 64 Comments sorted by
  • Yes Ideally this would be the case. I started to talk about this here:

    At the very least, we need to adopt a standard output file, like PDF so people can get to the information easily. Honestly, there are bits and pieces everywhere. There's a Wiki, a Blog, this forum and a main website. There's even a couple "build" sites that have been used.

    Organizing and sorting through all this is needed for sure. This is not my area of expertise, so I wait.....:)

    The Dawg
  • I agree with this as well. I have done several CAD drawings over the last several days and have been experimenting with various free tools that are available. It looks like FreeCad is the best open source solution for producing the 2D part drawings, although it doesn't yet have support for adding dimensions to these drawings. It spits out very nice SVG drawings which need a bit of manual tweaking at the moment but I think that is definitely going to be the best route to go. The project is being actively developed, with many commits even over the last few weeks and most of the issues with the FreeCad 2D drawings should be easily resolvable.

    As far as actually building the 3d models that are used to produce the various 2d sketches, I have been using BRL-CAD to create them, exporting them to STL format and then importing them into FreeCad to make 2D sketches. Others could either do the same or model in FreeCad directly, or in another program that can export to something FreeCad can read. This would allow us to standardize on FreeCad's .fcstd file format for uploads to the wiki but we could accept files in any format FreeCad reads as well, including DXF and other common formats.

    As far as units and the dimensions of piping/angle iron/flat iron used to build the models, we should make a page on the wiki with common standard and metric sizes of each type of thing as well as sourcing and pricing info. Then we restrict ourselves to building models only using parts from one list or the other (i.e. an all standard version of the machine or a all metric version). Designers could design the model in either one and it should be relatively straightforward for them or anyone else to make the "other unit" version by just going through the parts list item by item and replacing with the analogue from the other system. The model can then just have its measurements tweaked on each part (taking a couple hours in total) and then you would have a new set of blueprints for the other measurement system.

    For some good examples of models produced using the toolchain described above see the following pages on the wiki (the page background for the freecad drawings is just an SVG file that we could replace with an official OSE one):
  • I looked at BRL-CAD a while back and it is a really primitive tool, not really user friendly or up to current standards. This is a case where we should bite to bullet and try to acquire some floating licenses of a more modern software. The features available really do make a world of difference. My personal choice, motivated by budget limitations and a need for a serious tool compatible to the expensive software I use at work, is alibre design. A single seat of their basic software is 200 dollars, which is outrageously cheap, and their fully featured expert edition is only 2000 dollars and has tons of features.

    My dealings with alibre so far have been good, and they seem very willing to negotiate on the price and set up installment plans (which is what I did). I cannot encourage this enough, and if there was enough interest I would even look into donating some personal edition seats to the OSE if it would help improve our CAD processes
  • heyo, i dont know much about 3d modeling, how do you guys view google sketchup? ive been using it because i know about it and its free. i know their file format isnt compatible with much of anything else. what other reasons should i seek out something else?
  • You are certainly free to use commercial software but I don't think you will convince anyone that that should be the official format or tool. As long as your program is capable of exporting to a format read by the OpenSource tools I say go for it, but I think that anyone should be able to contribute and that means using a free format at least in the central repository.

    BRL-CAD is definitely not for the light hearted but it is a pretty powerful system. Also, FreeCad is much more suited to the general audience and the two are at least reasonably compatible at the moment. If we got in touch with the freecad developer and told him we were considering making it the official way to contribute CAD work I think he would be willing to add any features we need. Also a few people putting in 200 dollars each would give us enough money to set up some bounties to have features added. We are not going to re-create a commercial CAD suite with a few bounties but we could go quite a ways I think.
  • Are you implying that all of the tools MUST be open source? I'm fairly certain that most of the tools being used are commercial products, and while I completely support developing a free and open source CAD system, I don't believe we are close enough to an adequate system to intentionally cripple ourselves with inferior tools too early in the process.

    The implication of such suggestions is that engineering so unimportant to the overall process that the quality of the tools used is irrelevant. Unfortunately this isn't a software project, its ultimately a production project and that means that the assumptions and constraints are very different. I am not simply suggesting that we use this particular software, I'm attempting to help with the costs through major donations. Now compare the features and realistically assess the benefits of having the additional modules available. If your only objection is that it isn't free and open source, I would say its a bit over-optimistic and impractical at this time to constrain ourselves in this way. That being said, I am eager to find an adequate free and open source alternative, but between sacrificing features or money I think the advanced features are more than worth it the money.
  • maybe we should make like a point system to rate the softwares?
    like all i know about it sketchup.. so...

    sketchup basic version
    cost: free (+4)
    open source: no (-1)
    file formats: few (-3)
    tools: basic 3d (+1)

    total: +1

    k, feel free to re score, i dont know what everything should be weighted. we could also take on discussing each point's weight.

    maybe do the same thing for the softwares you are familiar with.
  • what does everyone think the "make or break" features should be?

    im sorta leaning with andrew that it should be free. but i could see a world where the people that just want to try out modeling can use a free software and then the guys who do the final release drawings could use more advandced stuff. but it would be nice if we had a standard for both just so there is a consistent procedure for sharing and using the files.

    what final outputs do we need? what could make or break that? a 3d model and a 2d diagram? what if it can do one but not the other.

    should we use different programs for torch table/3d printing/manual welding diagrams? or should we expect one program to output for all the different modes?
  • It would be a mistake I think to limit ourselves to open source in any way here. My first question would be why? What do we accomplish by doing this?

    There are de facto standards in place now that we can cling to. Adobe acrobat files (PDF) being one of them. AutoCad (DXF) files have been around for decades so just about every decent program out there supports it.

    For 2D based files the above would work fine. For 3D it gets more complicated. I don't think at this stage it will be practical to limit ourselves to one 3D file format. I personally use Rhino, Solidworks and sometimes Autocad. There are many others. 3D programs, especially the parametric ones are complex and don't play well with others. If I had to choose a format it would be IGES.

    In the end, it will be very difficult to share back and forth within a certain assembly unless we're all using the same program. Well then we run into cross platform issues. I'm IBM, what about you?

    Then you get into CAM files and it gets even more complicated. Some machines use G Code directly and others convert vector based files to motor controls on their own. I could go on and on here.

    But yes, we really need to talk more about this.

    The Dawg
  • I'm certainly not insisting that the _tools_ be open source but I think the format chosen for the various types of things should be something that there are open source programs to deal with, at least to some extent.

    For example, if we want to distribute the CAD files with the build instructions, they are useless to the people this hardware is intended for if they cannot be viewed by some software we can distribute with our instructions, videos, ect, and that means there has to be some open source program capable of at least reading and displaying our preferred file format.

    I don't know too much about the various CAD file formats but IGES does seem like it is a good one to standardize on. BRL-CAD can read and write it, and supposedly FreeCad can too. I am sure ProE and Solidworks would support it and I think I saw that alibre does as well. Assuming all these programs can actually read the format and that it stores the 3d structure well enough for us to do what we need to do (make 2d and 3d renderings, create CNC programs, create torch table routines, and create parts lists) then that should work. With this strategy you can work in whatever program you want and then just export your finished results to the standard format and upload it to the wiki. We need to make sure though that you can move amongst the various programs with no (or at least minimal) loss of information along the way.

    With regard to using the same program for designing, testing, CNC programming, etc I don't think there are programs that do all this unless you spend many thousands of dollars per seat which is probably not what we want to do so we will likely have to find programs to fill each of these needs. BRL-CAD and FreeCad take care of a lot of the early prototyping work though, even if they are not the easiest to use.
  • Sadly, lossless transfer is the holy grail of CAD and doesn't yet exist (to my knowledge). There are a variety of different standards that exist for data transfer, but most generally make later modification of the part very difficult if not impossible.

    Perhaps it would better to just focus on ensuring that all drawings produced are consistently dimensioned and all use GD&T. The standardization of file formats can come later when the tools are more mature. How many other people know about GD&T?
  • Yeah, I am noticing that lossless is pretty much impossible, however if all the dimensions carry over which almost any format to any other format will preserve we we can pass around an "approximate design" which is close to the final design until we get it mostly worked out and then the final version can be stabilized into some long term storage format.

    The reason you don't get lossless transfer is because not everyone stores materials the same way, some formats don't store it at all, some use BREP whereas some use CSG, etc. However, most of the common formats are convertible if all you want is the basic shape of the parts and the dimensions. And it is only the stabilized design that we are interested in producing CNC and torch table routines for so all that can be ignored until the design is finalized.
  • The thing I really like about alibre is how many different file formats it will recognize. Still at the very least we need to create uniform drawings.
  • so what did we decide on?

    software doesnt matter, file format doesnt matter. how do we dictate uniform drawings?
  • What do you mean by 'uniform drawings'. I assume you mean using standardized building materials, deciding on standard methods of connecting metal together, deciding whether to use 'standard' or metric units, etc. If this is what you mean, go ahead and draw up some kind of a guide for what how you think it should be done and put it on the 'CAD team' page on the wiki. I don't know enough to draw up such a document and so would be fine with whatever you come up with. Once we get that in place maybe we can find a common file format that works with what we have in the design document as well as how we want the development pipeline to work.
  • i downloaded brl-cad. i guess "archer" is the drawing program? i probly need to read up on the website instructions before i try to start drawing.
  • You can use archer which is the newer one, I use MGED which is a command-line way of entering/manipulating primitives. MGED renders its display to another window which pops up when you open it. It is a bit difficult to learn but once you are familiar with it it is easy to create/move/modify building pieces b precise amounts since you type in the commands. You have to do a lot of math manually though which is the downside.

    There are quite a few good tutorials on BRL-CAD in the form of ~100 page pdf's. I went through a couple of them over the past week or so as well as reading a bunch on the wiki and you get used to the program pretty quickly. FreeCad looks like a much more user friendly program but BRL-CAD is much more sophisticated.
  • k ill try freecad too and see how i feel
  • For freecad the best documentation available seems to be the series of youtube videos they have. They let you see what the program is capable of but they are not terribly useful in actually learning how to use it. If we do decide to use freecad for some portion of the dev work I would probbly try to write some documentation for it with specific emphasis on designing for the OSE project (i.e. how to do the file exports to whatever formats we decide on, etc). Also, I am on skype if you or anyone else wanna chat sometime. It is much easier to do this sort of discussion in that fashion than it is to do it via forum posts.

    We can discuss these things or how to use software, how to organize the wiki, whatever.
  • I was talking about the layout of things like title blocks and so forth.

    I also thing some training and discussion of GD&T, would be very helpful... you can never review GD&T too much, and its a somewhat difficult subject for those who have never really encountered it much before. My previous messages were all from my phone and for some reason Android (or at least the Dolphin browser android) doesn't really like the OSE wiki or this forum very much. It would be nice to have a standard file type (digital) but since it seems unlikely that efforts to implement that would be particularly fruitful I'm willing to settle on simply standardizing the drawings.

    As for the other standards you mentioned, yes they are absolutely vital. In order to develop those we should develop a process similar to the one used to choose the 50 GVCS technologies, only specific to each of the particular domains (manufacturing techniques, materials, standard fasteners, etc.)
  • The standardized manufacturing techniques is something I can start pages for on the wiki. I will do what I can to lay out the pages but will leave the details to those who have more domain experience. My expertise is primarily in computers and physics rather than CAD specifically but I will do what I can to help get the pages up and organized as best I can. I am almost finished with the first round of image categorization (~560 left) and once that is done I will have time to set up a few pages discussing standardization of the various techniques, as well as a summary of the outstanding questions and issues.
  • My vision here would be a system in place that would allow interested parties to contribute to a project but not necessarily be expected to output finished drawings or even standard solid models. As long as they can find a way to interact with their design team they're good to go.

    A core group of CAD members would then be responsible for taking all the input from various members (programs) and converting or even totally remaking them in order to produce presentable finished drawings and instructions. This way, the people that already have access to the best software and training to do a particular job can worry about polishing everything up.

    All I need as an experienced draftsman is a way to communicate with other team members effectively. Once I understand them, I can do the rest.

    The Dawg
  • I'm not *intending* on being in the CAD group, but from what little experience I've got with CAD, I'd suggest SolidWorks.

    - From what I see, most community colleges and universities have classes that use it.
    - It is pretty comprehensive - it can do strength analyses and whatnot.
    - It's probably got a pretty large community.
    - It seems to be somewhat open - it interfaces to LabVIEW for example.
    - I believe it does fluid flow to some extent too?

    As for publishing the CAD designs for OSE products, I'd suggest publishing both the native Solidworks projects as well as the models converted into a few different open source formats. So we'd be publishing 2 - 4 different formats of the same design.
  • The requirements for the finished drawings that I see are
    (1) capable of being read with free software on any operating system.
    (2) capable of being printed out for use in the shop. A laptop is not terribly compatible with torches for cutting and welding, for example.
    (3) separating text notes and instructions from the geometric layout. Since this is intended as a world project, that will make it easier to translate into various languages.

  • I think we are starting to get close to a process here. I like the idea of using several export formats of the same source model to try to capture as much detail about the design, even if not all the information can be contained in any one single file. The 3 requirements stated by Daniel are what I was concerned about with using commercial software as number 1 and 2 would likely be problematic (3 would be a question of what software is used and both OS and Commercial software probably have programs that deal with that).

    Basically it seems like almost every program has its own internal format that can store both 2D and 3D about the design. However these do not export well from one program to another. If we passed around preliminary designs as a two file package (one like DXF for 2d and something like STL or IGES for 3D) would that resolve most of the issues? It seems like most OpenSource programs understand these formats so I would assume the commercial apps understand them as well. I like the idea of also always publishing the "native" format the model was originally built in as part of the package, then if another developer has that program they can just ignore the potentially "lossy" exports.
  • Solidworks is a nice program, and the program I use can read and write in the solidworks native filetype. I also agree with the assessment that we only really need a core group of dedicated cad people. At work I frequently get photographs, sketches, verbal descriptions, and occasionally physical prototypes. A design engineer will be given a cobbled together prototype and have to convert it from spot-welded and duct taped to a finished good that can be easily manufactured, eliminates the inefficiencies of the design prototype, and irons out all the wrinkles.

    In this engineering model the other engineers mainly focus on the effect they are trying to produce, and the physics behind that effect. When I look at the efforts thus far, I see that the projects have an abundance of electrical or mechanical engineers (the scientific effect guys) but not a single design engineer. Now this process of innovation is only the beginning of a long chain of processes that improve the product and prepare it for release. Especially if these tools are intended to be built and used in all sorts of different environments. Our future users may not be literate and most likely won't have many of the tools we have access to. How do you teach them how to read drawings, follow maintenance schedules, adhere to safety procedures, and so on? The only reliable solution is to attempt to design the machine so it can only be put together correctly, is super robust and can survive infrequent maintenance, and has safety interlocks that mandated safe operation. To implement even those requirements may force a design engineer to radically rework the whole product. Wanting it to be built anywhere means we have to dramatically limit the fabrication methods we design the product to be built using. This means vast swaths of otherwise valid designs will have to be scrapped if they contain even one part dependent upon advanced manufacturing capacities. This is very much like an insanely complicated Sudoku puzzle, with hundreds of columns and rows.

    I personally love doing design work of this type but for it to work the design engineer needs the support of the rest of the team to "meddle" with the other guys "perfect" design. Patience is also needed by everyone involved since design engineers go through hundreds of iterations in which they gradually "evolve" the design towards the specification. Most of these iterations are virtual, but there are still numerous physical tests that must be built and run to ensure particular solutions work as anticipated.

    The process may seem difficult and long winded, but its what separates dabbling from engineering.
  • since we're talking about it, i was thinking maybe we should identify the most likely failure modes for the machines? this would sort of push a basic safety awareness for people building and using the designs. will something break off and hurt someone or will it just break some teeth on a gear and stop spinning.
  • You can't really do a thorough analysis of failure points on a conceptual design, but on machines that are fairly mature like the CEB press we definately should do this. And we should look not only at catastrophic failure points, but also on points that will receive excessive wear and thus fail quietly later on and render the machine basically useless until they are repaired or replaced.
  • Just an update, I am in the process of developing a standard title block for everyone's consideration, I should have something posted in the next day or two.
  • As much as I welcome the structure I think we need to also realize that open source is a process.  Even more than the destination, I think it's about the journey.  So once something functions well enough to get the job done and we've met a basic set of conditions we need to do a release and get it out there.  Then we let the process work it's magic.  We let first adopters give us feedback.  We let the design evolve over time.

    What I'm trying to say is lets not let the structure take over either.  We are all volunteers, lets make the structure as easy to work with as possible.  As welcoming as possible.  Words like inclusive come to mind rather than exclusive.

    The Dawg
  • I agree a balance is needed, and I certainly don't want to recreate the corporate dictatorship model I have to fight with at work, but right now we are way too far into the "spontaneous chaos" side. I like to think of it like language... standards should be the grammar but you can use them to say anything.
  • Aneiren, what format are you planning to make the title block for the drawings in.  I plan on uploading a new 2d sketch of the rototiller drawings with the actual tiller teeth on it so the measurements of the existing machine can be added.  If I had your title block in SVG format I could use that for the page background in FreeCad when I do the export.  It would be nice to get that in use right away.  If you are doing it in something else I can convert it to SVG with inkscape easily enough but it would take 1/2 hour or so to do.  As a starting point, you may want to look at the one FreeCad ships with as it is already a nice starting point and it is already in SVG, which is the best format for something like that (at least a vector drawing anyway, if not SVG).  Have a look at the rototiller page on the wiki to see what it looks like.
  • Okay, will do. When I get home tonight I will work to expedite the process.
  • Cool.  I am just about to upload another drawing for the rototiller now but I will do the next version with the new title block then.

    EDIT:  Just in case you find this useful, here is a category with several versions of the OSE logo and also the CC license emblem, which is what I am assuming we would use for the 2D sketches that will have the title block you are designing.
  • Do we have a vector version of the logo?  It sure makes scaling easy and I think looks better in the end.

    The Dawg
  • It would be good to get a vector version, although the regular logo can be embedded for now as that is better than nothing.

    I added several tables to the CAD team page on the wiki for standardaized building materials, fasterners, and the like.  There should probably be a few more tables, and the only items I filled in were just random picks from the first bolt sales website on google, but the tables are in place now so people can see how they are made and hopefully can fill them in.  If no one does it I will eventually fill them in but it would be good if someone with fabrication experience would pick out good choices for each of the various options.

    We probably don't want to "hunt" for the best price available for each component, but rather try to find the typical price you would pay without too much searching.  Also, we want to try to get the best deal we can for the building materials if we have to buy them so if there are common sizes that are cheaper those are the ones we want to use.  Not only will startup villages have an easier time getting going, but as they acquire tools and begin to make some of these things themselves, being able to sell the extras they make is a key part of the overall strategy so we want them manufacturing the common sizes that are easy to sell.

  • Recently I decided to
    re-learn CAD (after 20 years) to help OSE in some way. After 
    reading  all the posts in this tread,  didn't see any
    comments about DraftSight. This software was my choice to start, after
    trying some of the softwares described at the CAD wiki:
    ( .

    DraftSight is free,
    works in Linux, Mac and Windows, is dwg native, and can export in
    dxf and other formats. I can attest that it is ease do learn, at
    least for easy 2D drawing.

    I think that I can't
    contribute to much with the standards discussions, as I'm just beginning again
    with CAD, but I'm available to do some drawing (even the boring
    ones!) as training, if I get access to standards and templates.

  • Draftsight seems like a decent 2D tool, but for most of our applications I think we really do need to use 3D Parametric modeling. Of course, practice and experience with a 2D tool is still valuable and will help you throughout this process.

  • Thanks for the clarification about DraftSight. I think that 2D drawing will be necessary anyway in the documentation phase of a project, but I agree that 3D is important for modeling.  So, from a free/open source perspective, what software do you sugest to start with 3D parametric modeling? I would like to start studing something that is well acepted in  the OSE design comunity.
  • Well I haven't found any good 3D parametric CAD solutions that are complete. There is FreeCAD which shows progress but is still largely incomplete, and there is BRL-CAD which is a somewhat outdated system. If you are really good with computers and programming I would suggest you help out with FreeCAD. Otherwise there is BRL... but I am personally not a fan and I think it will teach you bad methods that won't transfer to a modern CAD system.
  • I just got done writing a tutorial on FreeCAD.  The tutorial is to build a simple engine block and crankcase with a spline curve forming the outside shape of the block.  Here is a link to the tutorial in case anyone here is interested.
  • Will It Print?

    This should be the central question to keep in mind as we make decisions regarding CAD.

    The end goal is full automation of GVCS technologies. Fabrication and operation.

    Right now, there's a big bottleneck on the software side. While traditional CAD drawings and designs are useful for hand tool fabrication, robotic automation is a whole different ballgame. As another point. our workflow and organizational structure is so chaotic as to make it quite difficult to standardize to one particular program. The best programs are very expensive and tend to be quite locked down.

    Open Source CAD just plain sucks at the moment. That's ok though. It will get better with time. As long as it answers the key question "Will it Print?", we can use it right now.

    With the ability to have to CNC our equipment with a minimal amount of onsite labor, we have the potential to massively increase our production output, provided we have the designs ready to go. Our designs are relatively simple, and so long as they can be easily replicated, I'd favor people learn whatever tool they can create quickly and effectively on. If that's a fancy $5,000 piece of software, or a very basic free program. So long as our file formats are consistently printable, it matters little as much where it came from.

    The gold standard should be whether or not the end product is fab-able. Preferably with automated equipment.

    Our torch table is coming online, and we've got MIT collaborators along with some some people with reprap experience joining us. We are also in contact with the Lasersaur group. There are quite a few others as well. Basically, in the next few months we're bringing a huge amount of automated equipment online. Our decisions with CAD standards and such should keep this as a central focus as we pool our resources.

    We hope to be organizing our CAD groups soon so we can go nuts on the prototyping. If you're interested in being on that list, please be sure you've filled out the Team Culturing Survey. Please be sure to list the CAD programs you prefer. We'll be culling a contact list from that soon, and we aim to have some online meetings where we can really start going at the CAD work soon.

    It's a lot of fun designing something, and then seeing it built so quickly. We'd like to share that joy with as many people as possible.

    Stay tuned!

  • As an aside, has some amazing realtime collaboration options. Not sure if this its the best tool for our job, but I think the realtime factor could make for some very cool brainstorming sessions. Export to DXF =>Gcode converter=>Linux EMC2 means we could print anything from a design meeting and see printed/fabbed parts within the hour.

    Pico-project that into our workshop surfaces and we could have spontaneous live design sessions.

    I'm curious what the collaboration abilities have been added to other CAD programs recently.

  • One of the things that I find most wonderful about sketch-driven parametric CAD programs is their ability to automate the actual design process within the software as well.  Once the general layout has been done these programs allow the dimensions of the sketches to be driven by spreadsheets (such as Excel) and so you can make a design that can be modified and controlled without actually having to go in and individually manipulate the elements.

    I look forward to the coming automation, and your pragmatic stance of "Will it Print" is a good one, although I would imagine that it would be "Can machine instructions be derived from it?"  I personally favor as much integration as is possible, which is why the prospect of Aras is so exciting.  It can serve as a sort of "Manufacturing Operating System" and we can encourage the FreeCAD guys to build in integration and work towards the integration of a variety of different software tools so that anyone with a browser can log onto an Aras session, modify parts, run simulations, and initiate Automated Manufacturing.  Integration of Aras into the larger picture will allow everyone to see, at a glance, the total inventory of materials available as well as the active tasks and projects.  I believe it has a scheduling module that would allow us to do lights-out style manufacturing, simultaneously working on the manufacture of several items at the same time.  Its the automated factory trend that manufacturers are beginning to embrace, but if we get there first we can influence how this new tool is used.

    Perhaps this isn't what other people have in mind?  I would be curious to know what everyone else's "Ideal Industrial Complex" looks like?  The Cottage System?
  • @aneiren

    I think you hit the nail on the head hear....TWICE !... in this thread...excellent work..

    "How do you teach them how to read drawings, follow maintenance
    schedules, adhere to safety procedures, and so on? The only reliable
    solution is to attempt to design the machine so it can only be put
    together correctly, is super robust and can survive infrequent
    maintenance, and has safety interlocks that mandated safe operation. To
    implement even those requirements may force a design engineer to
    radically rework the whole product. Wanting it to be built anywhere
    means we have to dramatically limit the fabrication methods we design
    the product to be built using"

    I think this statement holds a lot of weight, not only about the fabrication methods...but the materials used... has anyone considered maybe limiting the material of some of the projects to cut down on complexity. ? ... I would love feedback on this...but I think we should consider that in order to design and then build these machines, they should be built from readily accessible parts ...of course we can't buy everything at Home Depot, Lowes, and Radio Shack, but the fewer the parts the better...also makes the device less susceptible to failure, and easier to fix. I am a big history of the success stories of WW2 was the Sherman tank...not because we built so damm many of them...but because of how few parts they have and the ease of fixing them..same goes for the willies jeep...(food for thought)

    I have been using FreeCAD For some time, it is a great tool, but still under development, I've had my issues with it, things could be easier. I think your recommendation for the Alibre Design PE is a great idea... I have used it in the past as well, and in my opinion it is a more intuitive product, with a much greater support base, documentation, and users.

    Just a side note on the this site, and the organization of ideas...standards...ect...  I had to search the forum for the word "CAD" and read through probably 6 or more threads till I hit this discussion...(which is exactly what I was looking for ! )  Which kinda sucks because I think this topic is critical to the mission at hand. I know the debate will go on about what product to use, and the standards around the design practice. Maybe we could post up a questionnaire to get a consensus of what CAD application people are using ?

    While we are on the topic of standards, has anyone given thought to a repository of common parts ? ... I just putting this up here because I don't know if everyone knows about it...but google sketchup has a huge repository of parts

    obviously for their sketchup software... but would their be a benefit in creating a similar repository of standard GVCS components....there by also cutting down the complexity of any given device .... I'd love to hear feedback on this.

    Great post guys...maybe we can make this a "sticky" and keep it at the top of the Forum for a while.

  • And to extend the thought... what do people do who can't get to a home depot or etc.?

    I had hoped that this topic, as technical and practical concern would have garnered more feedback, but we're slowly making progress.

    What would be helpful (to the whole domain of open source hardware) is an open source equivalent of the ISO or the ANSI organizations. Perhaps the OSSO (open source standards organization)?
  • @aneiren, did you ever get that title block done?  I was planning on putting one together in SVG format so it can be used in FreeCAD.  I plan to put it together sometime today and will post it to the wiki when it is finished.

    @viper6277 I agree on the idea of trying to standardize parts to build from.  I have put together a few tables on the wiki and was hoping people (with more subject experience than me) could start filling the tables with sizes of common building elements that would be good choices.  If no one else fills them in I can go through and try to find good entries for the various tables but I am not an expert on this.
  • I was trying to get more information to be able to populate the title block with meaningful info (like project codes or manager approvals). The title block isn't really much more than a container for that sort of data, and we don't know what that data will be.

    I guess I can just bite the bullet and make it up, and if people don't like it then tough. Everything the OSE will have to be done the hard way because Generally Accepted Practices are dismissed by the leadership as too much work... just wing it.

    Anyways, I'm done complaining for now.
  • @viper6277 and @ AndrewBuck,  I'm also thinking in a list of standard materials for OSE. The idea is creating a classification of materials and parts, based on global availability. This list should help  to improve the designs to be really feasible anywhere in the world, and help builders to access the difficulties involved in getting the materials and parts for a GVCS project. Once defined the list, we can research for prices all around the world.

    For example:

    1-Global basic "comodized" Materials (something that you can find in a small size hardware store almost anywhere in the world)

    Portland cement
    Steel wire
    Steel pipes
    Steel bars
    Steel sheets
    plastic pipes, connectors and valves
    plastic roses, connectors and valves
    Plastic film
    glass sheets
    mirror sheets
    construction lumber

    2- parts that are found only in big cities around the globe

    hydraulic roses and connectors
    Hydraulic actuators
    Basic electronic parts (transistors, diodes, resistors, capacitors, basic integrated circuits)
    copper wire for motors and generators

    3- parts that are more difficult do get (very specialized supply chain, only easily available in developed countries)

    Specialized integrated circuits and microcontrollers (arduino)
    steeper motors and servos
    High power magnets (for DC motors and generators)
    Electronic sensors


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