[brtlatjgt]

Is anyone out there using Alibre and then importing files into Onecnc with success.

Note this post on Alibre forum:

"If someone has the knowledge and the time to explain the differences in solid modeling creation, I would really appreciate being taken to school on this subject.
I use OneCNC (in addition to Alibre) and have the ability to model (in OneCNC) in addition to its main function which is CAM. I run into problems when I import files, whether IGES or STEP, from Alibre to OneCNC.
Sometimes the toolpaths show a gap in some surface locations. Other times the projecting of a sketch to a solid or surface (in OneCNC) creates havic.
OneCNC will state that the model imported is the problem. That the precision or tolerance of the imported model is too loose (my words not theirs).
OneCNC prides themselves on creating very accurate and tight models. Their models are NERBs (I believe).
I would really like to utilize parts created in Alibre, imported into OneCNC, without recreating them. I need to assume that my solids that are created in Alibre were done correctly. I certainly did my best, using constraints and verifying that I have zero degrees of freedom.
Some questions are:
1. What does Alibre use to create solids (ACIS?)? What does this mean if ACIS?
2. Is there the ability to export solids from Alibre and set the tolerance or precision level?
3. Does tolerances or precision only refer to NERB surfaces and not Alibre solids?
4. Many OneCNC users utilize Solidworks and there doesn't appear to be importing issues with their solids. Are solids created in Alibre that different from Solidworks?
Any insight would be appreciated."


I just purchased Alibre myself and after I get the hang of drawing with it I want to finally purchase some Cam software. Onecnc was the one I thought I would like to purchase.

Your thoughts please.

[cncadmin]

Their is no exporting issues with onecnc, I just export the model as a IGES and onecnc converts it perfectly.

[CAM_MAN]

There are two different standards used for solid models, a parasolids kernel and an acis kernel. Try to export out an .xt or an .xb from Alibre and read it in to OneCNC. Also make sure that your model is "rebuilt" before saving and that you don't have any incomplete features.

[budgetcnc]

Alibre seems a bit hit and miss with the step although quite often good depending on the model. Be sure to rebuild your model or you will/could have problems we think thats where a problem can come from. Alibre iges we import all the time into OneCNC never have a problem. It must be Alibre because we never have problems with step from Solidworks or Inventor. Onecnc files import is very good we find.

[ChrisJ]

Hi Paul,

Curious which package from OneCNC are you using?

I have found that OneCNC will import both a STEP and a IGES model from Alibre without a problem (most cases). But if you try and manipulate the model in anyway, keep your fingers crossed. Manipulating the STEP file, you can forget about it, it will crash. Manipulating a IGES file, well so far it has a 50% hit rate, based on my experience.

One example of manipulating the model is this: "extracting the surfaces" and then re-merging them back to a solid. Something one should be able to perform without a problem.

I took some simple models created in OneCNC and exported into IGES and STEP. The STEP file crashes in Alibre. The IGES file imports into Alibre but has "Edge" errors, when performing a "check part" in Alibre.

Anyway.... I am still messing with the translations. Also have communicated with Greg Milliken, CEO and President of Alibre, to see where the problems ly if some improvements can be made.

Chris

[cncadmin]

I'm using OnecncXR.

[ChrisJ]

More specifically, assuming it is the mill package since it is the XR, is it Express, Advantage, Professional or Expert series?

I am using Expert and have the ability to manipulate the models that I import. In the Advantage and Express, you can not. This is where most of my importing problems occur, on the manipulation.

Chris

[cncadmin]

I have the expert series.

[ChrisJ]

Paul,

Could you do me a favor.

I just modeled a simple cube with a round fillet on 4 edges and chamfer edges on the opposite 4 edges.

I exported to IGES, imported into OneCNC. That works fine. Now, extract the solid into surfaces and then re-merge the surfaces back into a solid. When re-merging, it crashes on my system. Would like to know if you receive the same results.

BTW: I tried exporting that same model from Alibre in STEP and it came up with an error and would not complete the execution. Could you try exporting into one of the STEP options (203, 214) and see if it works?

Chris

[budgetcnc]

A tip on importing from Alibre that we use sometimes with step is export it again then import the export and it seems to tidy it up and works ok. So it mustn't be too much wrong. I would just get a file that you make in Alibre that wont re import its own file send the file to support that way they can sort it.

[ChrisJ]

If I understood you correctly, you are looking to improve the file in Alibre.

I am trying to do it the other way around. Taking a modeled Alibre file and porting it over into OneCNC without OneCNC locking up on me.

Chris

[cncadmin]

OK I did what you asked ( i think) and when I tried to import in as a stp into albire I got a file not imported due to errors.

[ChrisJ]

Actually the file is an Alibre part file. You can open it as a part.

If that works, and there should be no reason why it shouldn't, if you could then export as IGES and as STEP(s) for importing into OneCNC.

Once in OneCNC try to manipulate the file, such as extract surfaces and then remerging the surfaces back into solids.

Let me know if you have some success.

Thank you
Chris

[OneCNC]

Chris,

We received a copy of Alibre this morning and I set about looking at the issue. Thanks Alibre.

I opened the file and exported it as an IGES file. The file came in as individual surfaces, rather than a solid, and upon attempting to merge them they file caused an error in OneCNC .

I then checked various export settings in Alibre: Without really knowing the program I made a few changes that seemed to resolve the problem:

1. In File > Properties > Units : I changed precision to 6.
2. In Physical I changed accuracy to very high. And applied changes to system and current document.

I then re exported the model as an IGES and a STEP. The IGES model came in as individual surfaces that again would not merge. The STEP 203 and 214 imported as solids, could be disconnected (broken down into their individual surfaces) and then remerged to form a solid. I also removed an individual surface and recreated it using the bounding surfaces without error.

I further tested the STEP files using a boolean function and both worked fine in this test.

I would say at this point that the STEP files would be the better of the export options.

Attached are the STEP models for review.

OneCNC-USA

[ChrisJ]

Hhmmm....

I did download your two step files and also had success loading them, extracting into surfaces and then re-merging them. I was not so successful with a step file on my original post. I need to figure out why.

Regarding these two settings, I have to wonder if they affect the quality/precision of the export. The first one you indicate is described as a Display Unit Precision. The second is described under Physical where I believe the setting you pick will calculate the data at a higher precision, but only affects that calculation performed at that very moment.

That aside... Thank you for taking a look. I will continue to keep my fingers crossed when I try to translate.

Since it appears that Alibre does not store the data to as many decimal places as OneCNC, or does not export the data to as many decimal places as OneCNC is capable of importing, I can only hope that Alibre adds some export options in the future to close the gap on the export/import complications.

I tried translating the files the other way. I took a OneCNC file, exported into STEP/IGES/Rhino and tried importing into Alibre. None of them imported correctly into Alibre. The Rhino file imported no problem into Rhino (demonstation copy) though. Hhmmm... thought for Alibre.

I have passed some files on to Alibre. I can only hope they are able to determine what some of the (their?) issues are. I am trying not to point fingers. :tired: Only trying to point out possible areas of improvement.

Chris

[ChrisJ]

Here is the response I received from Alibre on the Units and Physical settings:

In response to your questions about unit settings and physical property calculations, the accuracy of the exported file will remain constant regardless of how you apply settings in Alibre Design. The decimal place settings and accuracy settings merely control the level of display for decimal place calculations related to dimensioning, physical property calculations, etc.


Chris