.STP (STEP 203/204) export

[rwp]

Because we're pretty sure geomagic is a ending story, we will move to another 3D-CAD program(we are thinking about space claim :?: :roll: ).

Because we don't want to lose our 3D drawings (2D-drawings can't be imported in a new program i guess) we want to export
this files as a STEP and import it in a new program.

Now i found a problem with this. Some drawings we export as a .STP (Especially when it contains a imported .stp of a cilinder) another programm will turn some parts 90 degrees. We tested it in Solidworks, Ironcad and Spaceclaim.

When i import the same .STP file in geomagic, the parts will not turn the 90 Degrees.

So i am pretty sure its a geomagic thing, anyone knows how to solve this problem?

 

[bigseb]

Now i found a problem with this. Some drawings we export as a .STP (Especially when it contains a imported .stp of a cilinder) another programm will turn some parts 90 degrees. We tested it in Solidworks, Ironcad and Spaceclaim.

When i import the same .STP file in geomagic, the parts will not turn the 90 Degrees.

Be aware:

Not all software have the axis facing the same direction. Not sure about Spaceclaim but have a look at the layout of the axis.

 

[rwp]

Re: .STP (STEP 203/214) export

Thanks for your quick reply.

I know the axis facing thing, but thats the import direction of the whole .STP file.
Maybe i was not clear, but i mean just 1 or 2 part turns 90 degrees.
See the attached picture, the shaft turns 90 degrees, and the top-mounting plate on the cilinder turns as well 90 degrees but in another direction. All other parts are correct.

 

[bigseb]

Very strange. If you like you can send me the Geomagic package: seb@tynetool.skynet.co.uk then I can check it out too.

 

[DavidJ]

Transfer between CAD systems can run into problems.

SolidWorks and GD interpret the STEP standards differently for example - that is why GD has a SW export option.

Things to try - check for other formats that are common to GD and your replacement, I've used both ACIS and parasolid formats with some success to transfer data when STEP has failed me.

Review any import settings in the other CAD package (like GD's own import options).

Maybe try going via an intermediary program - I used CADExchanger for a long time (though mainly for opening STEP files that GD couldn't import, then saving as STEP which would import). The trial version of CADExchanger is much more tightly controlled now than previously, but the trial period might be enough to help out.

Be careful with assemblies - the constraints are not defined in the STEP file, only positions. At some point you'll likely have to rebuild the constraints in the new system (which would solve the orientation issue in your example).

For 2D drawings - you can print to PDF

 

[Giecon.nl]

If you do sheet metal I would also look at zw3d. Whatever you do, do some real life serious testing during longer a period. Don't base your choice on supplier demo's.
I went with zw3d almost a year ago no regrets.

 

[rwp]

I did a bit more testing.
Tried it with anchor parts, colors of parts, with and without configuration.... And lots more of (Stupid?) tests...
I am a little bit further now...
The problem are the files wich are turning the 90 degrees. It doesn't matter in wich assambly they are.

So i made a assambly of only 1 flat sheet metal plate (with 2 cuts to recognize each side), and the part. Even then its turning, see attached picture.

Its a imported Step file from FESTO. But the strange thing is:
1) some parts from FESTO got this problem, some doesnt.
2) If I re-open the .STP file in Geomagic it is ok, but when i open it in another program it is not.

 

[rwp]

If you do sheet metal I would also look at zw3d. Whatever you do, do some real life serious testing during longer a period. Don't base your choice on supplier demo's.
I went with zw3d almost a year ago no regrets.

We checked zw3d as well... nice program. But we got a few main points a new program has to handle with.
1)A problem is that we want to use our old drawings. Most Feature based programs get really slow when you use a .STP file or something like that. Like GM!
2)Another problem we got with GM is opening our machines, there are so big that it takes a hour to open it. So we design them in smaller parts. A new program must be fast enough to open our whole machine.
3) We want a bit big supported program, so we don't have the GM problem again with no maintenance in a few years.

And ofcours it needs to do everything GM does, and not to expensive.

 

[rwp]

Very strange. If you like you can send me the Geomagic package: seb@tynetool.skynet.co.uk then I can check it out too.

https://we.tl/DFQx7NKmft

 

[bigseb]

Time to open files can be quite high. I don't think that's Geomagic specific though. We regularly get mould assembly steps from the companies like Land Rover and they can be around 600 to 700Mb and they take forever to open (15-30min). They take just as long in Powershape though so...

 

[rwp]

Time to open files can be quite high. I don't think that's Geomagic specific though. We regularly get mould assembly steps from the companies like Land Rover and they can be around 600 to 700Mb and they take forever to open (15-30min). They take just as long in Powershape though so...

True it'ss not a specific GM problem, we Tried a large .STP file in Geomagic (Crashed first 3 times) vs Ironcad (+/-25min) vs solidworks (+/-30 min) vs Spaceclaim(1min,40sec). And also After loading only in spaceclaim it was easy and smooth to turn-around the .stp and edit parts. So thats a reason we think about Spaceclaim. Speed and we can't find real negative points of the program.

 

[JST]

One issue with STP exports, is that you will LOSE all the part history, and may or may not be able to edit them the way you want to, later, such as if making a slightly modified version. It seems to be a designed-in, deliberate "feature" of the format.

Some programs will do OK with an STP import, finding geometry, and allowing normal editing of at least SOME features. Solidworks is good at that, GMD is not, for instance.

As for imported files, I see those were imported to GMD, made GMD parts, and then exported again to a different program. Imported parts from other sources are often problems, due to shortcuts taken, etc. I have not has any issues with parts from GMD to solidworks, Solidworks IS a good program. There are details about it, and its operation which I do not like, quite a few odd behaviors, and so forth. But it is a good, and capable program, of that there is not doubt.

While I do not think GMD is going away soon, I am pretty certain that Solidworks is not going anywhere. You could do worse than the most supported CAD program around....... And I say that as one who is not fond of the program.

 

[bigseb]

One issue with STP exports, is that you will LOSE all the part history, and may or may not be able to edit them the way you want to, later, such as if making a slightly modified version. It seems to be a designed-in, deliberate "feature" of the format.

Some programs will do OK with an STP import, finding geometry, and allowing normal editing of at least SOME features. Solidworks is good at that, GMD is not, for instance.

As for imported files, I see those were imported to GMD, made GMD parts, and then exported again to a different program. Imported parts from other sources are often problems, due to shortcuts taken, etc. I have not has any issues with parts from GMD to solidworks, Solidworks IS a good program. There are details about it, and its operation which I do not like, quite a few odd behaviors, and so forth. But it is a good, and capable program, of that there is not doubt.

While I do not think GMD is going away soon, I am pretty certain that Solidworks is not going anywhere. You could do worse than the most supported CAD program around....... And I say that as one who is not fond of the program.

Losing part history drastically decreases the file size making it ideal for exchange.

Yeah SW's feature detection is pretty nifty. Often wish GD had that. On the other hand it doesn't recreate support datums like planes and axis and so on. So while it can recognize an extrusion, chamfer or whatever it falls over when you do more than increase the length of the extrusion or size of the chamfer. Shifting the sketch of an extrusion or changing the (directional) angle of an extrusion and you're in a world of hurt. So in this case I feel SW's feature recognition is no different to GD's direct editing. In some ways I prefer the direct editing route because it leaves the original stp file intact.

As far as working with imported files goes, GD requires solid parts. If the imported part is not solid then you will run into problems. The part checker is great to check if everything is ok. Often if only a handful of vertices show an error you can usually still go ahead and work with it without problems but as soon as edges and faces are highlighted... watch out! And that is no fault of GD. It really comes down to poor trimming on the suppliers side. When we get large assembly stp files and one part has error it can drastically increase the import time. Again, no fault of GD. I have seen SW show errors on imported files and not be able to repair then either. What I do is open the assembly in Moi and repair the error there. The fact that Moi picks on this too despite being a completely different type of software running on a different kernel highlights the fact that the file is the problem, not GD.

And yes, SW is pretty good. Pricey for what it is though imo. If money were no option I'd go for Catia. Still the best. Alas, money is a huge factor. IF GD should tank then most likely I'd just focus on Moi. V4 beta should out soon and its gonna be very special. And runs on Linux.

 

[JST]

Active point being that STP file is definitely NOT an ideal way to transfer parts between systems. Exactly WHAT is lost is perhaps less important than the fact that capability to do many things IS lost.

About the best that can be said for it is that at least it gives you a part you can probably measure up as you re-create it in the target system.

Or, if you really have no intent to modify the part, it generally gives you a solid part you can use as more or less of a dumb solid from then onward.

Where it REALLY falls down is with assemblies. EVERY constraint at the assembly level you export is lost, so the entire complex assembly is essentially just subassembies and parts that happen to be positioned in certain ways. You CAN almost instantly lose a great deal of work if you are not careful, and let the subassemblies move around.

I would advise really not counting on too much from the STP files aside from basic portability. Figure on having to do work on most of the parts and assemblies before you can really used them. And, it will be a good deal of work just to export everything.

To be quite honest, it will be a hell of a job, with issues that will probably be still hitting you well into the future. Worse than porting all your controls software to a new chip with completely new features.

You might be better off to convert to dongle and be reasonably assured that you will retain useful access to your parts almost no matter what happens to 3DS. You can create all new parts in whatever system you choose to move to.

 

[MikeHenry]

FWIW, Spaceclaim devotes a lot of attention to direct editing, which might make modifying dumb STEP files a bit easier

 

[Lew_Merrick]

STEP (ISO-10303) is undergoing the same "fate" as PDES (Product Description Exchange Specification) underwent in the early-1990's. It is being "gutted" by the same groups opposed to the concept of a useful Neutral Data Format by the same claims of intellectual property that were allowed to destroy PDES. The idea that the mathematics behind (say) ellipse mathematics are, somehow, intellectual property of one "group" or another is total BS, but such "claims" are being enforced.

 

[bigseb]

By whom? Is it Autodesk again?

 

[Lew_Merrick]

Sebastian -- It is basically the "government supported" corporations that "lead" in the CAD/CAM field.

 

[JST]

The smaller players ought to get together and create an interchange between their own programs.

With time, it will become a required feature in any such program. Nobody is worried about Catia.... or a level or two down as with Autodesk That level of CAD has very little NEED to communicate to others. And apparently some do not even bother to adhere to the STEP standards.

But the smaller players would get a net benefit from the ability to interchange data without it becoming a dumb solid. That IS a big issue with a smaller market program, folks want the ability to move data between programs and not be tied into their own little world.

 

[DavidJ]

The smaller players ought to get together and create an interchange between their own programs.

Well Alibre tried that years ago - published their internal file spec and proposed it as an extension to STEP (which is what it is). The full details were available on the web site for ages, but then vanished.

I'm not saying it couldn't happen - just that experience shows it isn't very likely.