Hi Jeff,

MoI is a very good modeling program and would be quite capable of doing what you need. I use it together with Rhino
but often just MoI does the trick.......Michael was also working on some translators (Step etc) so that would definitely
help us CAM guys right ??

Take a look at the gallery and tutes....then go find your credit card :-)). V2 Beta is now out and with even more
functionality !!

Njoy !

I found MoI models going directly into my cad/cam package are very nice AND seperate out VERY well. Better than many others I have tried. The ability to extract out the individual surfaces and edges makes toolpath generation a snap. If it is designable with MoI, I'll do it there.

Burr

Hi Paul,

> Michael was also working on some translators (Step etc) so that would
> definitely help us CAM guys right ??

Yup - actually STEP and SAT import and export are in for the next v2 beta release.

- Michael

Hi Jeff, yes MoI should work for this but there are a few caveats.


Data transfer should work well – I think it was starting with SolidWorks version 2006 that it added the ability to import .3dm files as another way to bring NURBS data into SolidWorks.

The .3dm file format is also the Rhino file format, so it may be listed on things labeled as “Rhino”. Your contacts are most likely a lot more familiar with Rhino than MoI so when it comes time to send them data you probably want to tell them you are sending them a Rhino .3dm file that might make more sense to them.

Additionally MoI also supports the IGES (.igs) format which is another way that can be used to transfer accurate NURBS surface data to many different CAD programs including SolidWorks. But I would recommend .3dm instead, it will probably be a smoother transfer. Also with the next v2 beta STEP (.stp) and SAT format will be added as well which are additional NURBS-based formats.


The caveat part is that in general MoI is not really designed to be a replacement for SolidWorks, it is more focused on a different area of making some basic solid modeling CAD type tools work well for artists who do not have a technical CAD background.


There are some functions of SolidWorks that are specifically oriented towards injection molded plastic design and that are very useful for that kind of thing. One pretty big area is shelling which is a common thing done for those kinds of parts. MoI does have a basic shelling mechanism but the one in SolidWorks is much more robust and can handle a lot more complex shapes with pieces that run into each other, etc...

Another area is that SolidWorks has some processes that make it easy to add stuff like stabilization ribs, some structural details like that which are common to these kinds of parts.

In MoI you would have to kind of model those types of things individually. Not impossible, but if you have quite a lot of them to do it will take significantly less time to do it in SolidWorks.


One way that could work pretty well is to generate the overall shape in MoI and then send that over to your contacts that have SolidWorks and have them do some of the sort of "manufacturing details" on it like calculating the shelling and inserting stabilization ribs, etc... That could be an effective combo.

The data that you send over in this way will be "real" NURBS data so it will be way more viable for your contacts to use your data directly as a basis to work off, which is just not going to happen when you send them polygon data (other than to just generate the part directly by STL and not do any further editing of it).


Also you may be able to get a pretty good inexpensive toolset by also throwing ViaCAD into the mix along with MoI, it is an inexpensive (like $100) CAD program that does happen to have a pretty good shelling module. It is not as easy to use as MoI, but it could definitely come in handy for doing the shelling if that part becomes a problem for you in MoI.


Definitely MoI’s UI is the most friendly way to get started in on NURBS modeling.


NURBS modeling will probably feel pretty strange to you at first because it uses a very different approach than subd modeling – for example in subd you probably avoid boolean operations except as a last resort and maybe not even then, however Booleans in NURBS are an essential “bread & butter” type operation that you usually try to target as the primary way of operating.

If you’ve done 2D illustration work with drawing vector curves, that may help you get more of a feel – in NURBS modeling you frequently draw 2D profile shapes as ways to drive the modeling, either for generating surfaces using those profiles as inputs (sweeping, extruding, etc..) or also cutting things by 2D profiles.

I’ve got some tutorial videos here: http://moi3d.com/1.0/docs/tutorials.htm which are intended to be an introduction to someone who does not have any NURBS background. I’d recommend giving a look over those to kind of get a feel for the workflow differences.

I may be able to give you some more detailed information if you can post some images of the types of things you want to create.

If your parts are pretty simple and don't have tons of ribs and fastener pieces to them, then it will be more likely that you could complete the whole finished design within MoI. The more of those kinds of things that you have then the more you will probably use MoI as the first stage design tool and then send the data downstream to have other people work on it some more to fill that stuff in.

- Michael

Thanks all for your input!
Michael Gibson emailed me with some more input specific to the project I am trying to get produced.
I can't show it publicly yet, but Michael thought it would be really hard to do in MoI or most NURBS CAD tools, so we decided to pay a local expert CAD guy to build the model for us. The manufacturers in China could not figure it out, but I think the guy here in the USA will do much better - with more tools, better direct communication and no language barrier. We shall see. ;-)
I will probably buy MoI anyway to start leaning NURBS - maybe next week - then Rhino when I get some more cash flow. It will probably be a long time before I can afford SolidWorks.
-Jeff

>>SAT import???

Do you mean what you say, Michael?
Speaking of export?, well. But you claimed it was really difficult to write a routines for reading in the file.... and now, I hear it is coming true :)

Petr

Hi Petr, yes that is correct - STEP and SAT with both import and export for each.

> But you claimed it was really difficult to write a routines for
> reading in the file.... and now, I hear it is coming true :)

Definitely importing is a much more difficult task.

But it helps speed things up a lot if you license a library that someone else wrote, which is what I did for this case. :) These will be using the HarmonyWare file translator libraries.

I don't really know a whole lot of details about SAT though, like if it tends to be particularly fussy or not, etc...

Is SAT import something that will be of particular use to you?

- Michael

Hi Michael,

>>Is SAT import something that will be of particular use to you?

Definitely yes. I need to translate from SAT to 3DM periodically (however not very frequently). Currently, I do that indirectly via SAT->IGES->3DM using CAM software package. And it's quite obscure way. Sometimes it works, sometimes it doesn't. So I hope MoI makes the process of translating easier.

Petr

Hi Michael,

> But it helps speed things up a lot if you license a library that someone else wrote,
> which is what I did for this case. :) These will be using the HarmonyWare file translator libraries.

Had a quick look at HarmonyWare and there is a mention of Parasolid XT, do you think there would be a chance this would be part of MoI's translation set in the near future, we find Parasolids translate very nicely into most solids cad programs, clean, accurate and always a solid, there is no need to join(sew) the model faces again to produce a solid once translated, which is the case with IGES translations, where depending on the accuracy of the the model rebuilding faces is not unusual to get it to join properly to produce a true solid.
Another thing is the file size, for example a model exported as IGES will come out at 6Mb and the same model exported as a Parasolid would be 2.4Mb.

So is there a possibility ? :)

Cheers

Hi Danny, there is definitely a possibility for that. But I kind of want to see how SAT and STEP work out first a bit before kind of diving in to Parasolid as well.

I can't remember if the HarmonyWare library supports both input and output for Parasolid, I will find out.

- Michael

Yes. I agree with Danny. I think the Parasolid (file format) is quite popular in CAM industry and it is often used as a geometric modeling kernel in CAM packages as well. So smooth interoperability between MoI and CAM would be ensured.

Another way to ensure a good result of creating a tool path geometry from a STL file would be to let users set up a "maximum distance to surface" for export to STL file (it is also on wishlist).

Petr

Hi Michael,

I'm wondering if STEP would be the right direction to include in the next set of translators for MoI, I've been in the engineering business for about 22 years now and remember when STEP was released in '95 and it was labled the translation format to supersede IGES, but I don't think it's taken off as first thought.

I'm sure you would of done your research but personaly I would really ask the industry who uses tranlators a lot and find out what translation format is 'really' preferred and not what you read, I know that the large manufacturing firms use STEP eg. GM and BOEING to name a few, they use it to translate not only model data also all other data that is attached to that model like Product Data Management, drafting, Geometric Dimensioning & Tolerancing, but I believe that the majority of the small businesses find STEP a complicated system, because of the different STEP standards so they opt for IGES (reason why IGES is still around) or Parasolid which will translate as a 'true' solid, also I forgot to mention that Parasolid will translate assembled models and stay as seperate assembled solids once translated, compared to IGES where you have to try and seperate the common mating surfaces of each part to try and join them to make separate solids, I believe STEP does this too but I'm not sure which standard.

Which STEP standard are you looking at is it STEP 203 ?

.

Hi Guys,

Step is a good translator to have on your side....however I do agree about XT parasolid and the integrity of solid data. Parasolid has intelligence
within the file which helps us do the many 'feature finds' in our CAM system, it also reports as true data should rather than all just free form.

The ability to export XT from Rhino would certainly get my vote but I get the sneaking suspicion it would increase the cost of the app no ???

Hey Paul,

> The ability to export XT from Rhino would certainly
> get my vote but I get the sneaking suspicion it would
> increase the cost of the app no ???

Now you've confused me dude................ http://www.rhino3d.com/4/help/fileio/file_formats.htm
did you mean MoI ?? :)

Cheers

Hey Danny,

Dohhhh !!!

Sorry I meant MoI......(Rhino on the brain)

Actually the exporter out of Rhino is rubbish and their answer to me was to buy Datakit because nobody gives
a flyin about engineering output...apparently anyway. Seemingly the translator was written by a graduate who then
well left.....

I hope MoI doesn't take this approach in years to come :-)

Hi Danny, re: Parasolid, it actually turns out that will not be an easy thing to add in anytime too soon.

HarmonyWare's Parasolid module is more of a work in progress - it actually only currently supports data import and not export yet. And actually the import is not fully refined yet itself either.

So sorry, that one is unfortunately not likely to happen right now.

- Michael

Hi Paul,

> I hope MoI doesn't take this approach in years to come :-)

No, I'm not very likely to get temporary interns to work for me... For my kind of work style that would just be too disruptive.

I'd rather license stuff from a company that is more dedicated to working on their stuff for a longer term.

- Michael

Hi Michael,

I hear you...and thanks for the additional formats in the next beta ;-)

Hi Danny,

> I'm wondering if STEP would be the right direction to include
> in the next set of translators for MoI, <....>

Well, it's pretty much a no-brainer in this particular case, because it happened to be very easy for me to add it.

The STEP library is a companion to the IGES library that I was already using from HarmonyWare, it used the same kind of interface method so it was about as close as possible to just dropping in a new feature without doing much work on my part. That doesn't happen very often! :)

The only reason I did not use it for v1 was purely to reduce my initial business start-up costs.

I needed to add SAT export to enable export from MoI into Revit for use by architects, so I thought this would be a good time to also add STEP into the mix since it did not take much extra effort from me to do it.


I certainly agree that STEP did not live up to its initial marketing as being a complete solution to interop and a total replacement for IGES - any hugely complex specification is not going to solve interop, it just leaves too many variables when you let a whole bunch of different people write code to try and work with that huge written standard. The only real way to make things better is to have a common body of code that can be freely used so that it isn't up to a whole bunch of different implementers to all write their own complex code. But STEP did not do that.

At any rate, it can certainly be useful - many STEP translators are pretty refined at this point and typically support transferring solids instead of just surfaces. Although IGES can support solids it is often not supported so typically IGES will be surface data only and require stitching back into solids.

It's just another option that might come in handy for NURBS data transfer, that's the way I look at it.

I'm not making any kind of political statement that STEP is the "way of the future" or anything like that by including it.


> Which STEP standard are you looking at is it STEP 203 ?

Yeah, it's variant 203: Configuration controlled 3D designs of mechanical parts and assemblies.

- Michael

Some more details on Parasolid export - Sol Foster (he's the HarmonyWare guy) says that he may be able to dig into Parasolid format some more starting sometime next year.

But he'll need some help from people that are willing to test it, it will probably take a fair amount of back-and-forth testing to get it tuned up to work right.

There are a few parts of the Parasolid format that involve kind of chained lists of interconnected data which will probably take some iterations to get working properly.

- Michael