STEP Files vs SAT Files Pros and Cons

[[Da...]]

I apologize if this topic has been covered already but I don't seem to have much luck with the search function on this forum. STEP vs SAT files, what are you guys using? Whats are the pro's and con's of each?

[[No...]]

We always use SAT/SAB if there's no NX model available. We never had any problems. On the other hand, we almost never use STEP, so I can't really compare both. One pro for SAT is that it's the genuine format of Calypso's CAD core.

[[Mi...]]

Our engineering dept. spits out step files so that's what we use. They use the .stp extension so Calypso has no problems but if I make changes to the file in Solidworks and save it I have to change the extension from .STEP to .stp Probably an easy fix but it doesn't cause any other issues so I just roll with it.

[[Ow...]]

I've been using ACIS (.sat) models for the last 14 years with very few problems and zero problems in the last 10 years.

[[Er...]]

Oh, intresting topic.

ACIS native format is always to prefer. Every conversion made is a potential source of error.
And ASIC is designed to be error free regardless of decimals. But it of corce depends on what CAD-core originally used
to create the model. ACIS is actually pretty remarkable 🙂

If I have a choise, I'll usually ask for a .sab-file. Why, they are smaller, and imports faster due to their binary format, .sat is in my case obsolete, since I don't care if it's readable text. I'm never going to read it anyway. The only benifit I can see with the .sat-format is if you control the kernel as it's incorprated in the same way it's in Calypso.

Then I can see the benifit of doing:

save_ent(model.sat,entity);

instead of:

save_ent(model.sab,entity);

Since the .sab would be a nightmare to debug.

How ever, converters are usually good, so in the end, it doesnt really make a difference.

[[Ri...]]

SAT/SAB - Native format used by Calypso (proprietary to Dassault - Catia/Solidworks). Comes standard.

STEP - Universal standard for 3d models. License has to be purchased to utilize.

If you have the option of one or the other, I'd go with SAT/SAB as it is native, there is no conversion, and no cost associated with it.

STEP is a good format, I have been using it for many years with no issues. Now IGES, that's a different topic.

[[Me...]]

Solidworks/Catia use Parasolid format.
AutoCAD/Inventor use ACIS format.
Calypso uses ACIS format.

Step files are clean and rarely give problems but are still a conversion from the native format.

Eric gives the best advice, IMO...

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I use ACIS on everything unless I'm getting errors in the model. This is usually due to compound curves and freeform geometry. Then I'll try step. And if that fails I'll use IGES, as it's really dirty but handles compound curves and freeform geometry in a pinch.

[[Ri...]]

https://en.wikipedia.org/wiki/ACIS

Autodesk can import ACIS, but they are always many revisions behind. Autodesk uses their own CAD kernel.

Parasolid is developed owned by NX (Siemens)

[[Am...]]

I have been using .sat and step files and haven't run into any issues with either. Engineering save them as step files but when I make the solids I use ACIS only because it is the native and there is a smaller chance something will go wrong. The other negative of using step files is you need to buy the add on to be able to use step files but if you already have it I don't think there is any problem using step I haven't run into any yet at least.

[[Da...]]

Thanks for all the great info! We have been using .SAT file format exclusively and the reason I brought this topic up is we have had a lot of issues withe features on the model such as bores, planes etc "solid filling" for lack of a better term. After we define a feature, apply the strategy, etc. etc. and then come back to make adjustments sometimes the bore will be solid filled and we can no longer see the strategy etc. and have to toggle views on/off to display the model properly again. This becomes very irritating, very fast.

I have seen this topic come up before but have yet to see or hear of a solution. I thought maybe using a different model format may be the answer, or perhaps one of the many software updates would have fixed it. Has anyone else had the same issue or know of a possible fix? What are we missing?

On the same note, the 2019 update seems to be very buggy overall even with all the current service packs and patches. It's really taking the fun out of programming with this software.

[[Th...]]

I'll preface this by saying neither of the applications I source CAD data from internally are native ACIS programs, but SAT files have been an absolute catastrophe for me. More often than not, files I import into Calypso have corrupted geometry that extends into infinity, and can't be fixed with the automatic healing function. At best, I can get stable SAT files out of Renishaw's special version of IronCAD, which only exports up to R24 of the kernel format, and only as long as I feed it a STEP file to start. I don't like having to base all my programs on a translated STEP file, but it's the only one that gives me usable models.

[[Me...]]

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I feel your pain.

Go to CAD/Settings/Geometry and uncheck the top 2-3 boxes. Show 2d geometry Features, 3d geometry features, and Show 3d features without CAD. The top 2 are always off for me. The 3rd depends on the program and what I want to see. Play around with them to find what works for you.

I have this set in a template I use for every program.

Robert

[[Ow...]]

Obviously, the software that creates the ACIS/.SAT file has a lot to do with it.
I've been using solidworks to create .sat files for 5 years with no problems. Because 90% of the models I use are created in solidworks by me personally, I know beyond the shadow of any doubt Calypso is not altering the model in any way.

[[Ga...]]

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I often get the same "solid filled" or random extraneous solid entities, sometimes I am able to remove them by going to CAD>Modify CAD Entities...>Hierarchy. Find the offending item on the entity list and right click/delete it. Then save/close and reopen the program. As I said, sometimes it works and sometimes it doesn't.