CMM to 3D CAD Communication - IGIS and DXF files

[KosmoQA]

Hello.
After many frustrating searches on the internet, I still can not seem to find the answer that I am looking for, so hopefully someone here can help.

We have a CMM. We also have 3D CAD software. We can send a 3D model from the CAD, in iges format, to the CMM and it will recognize it and we can then use it to write an inspection program (although the need for this has never come up). What we do have a need for, which we have as of yet been unable to do, is to measure a part (by touch probing or by scanning), saving the model as an iges file, and sending this model to the CAD software. We are able to send the model, and the CAD software is able to open it, but that's about where all progress stops. Basically, the model is not useable. All that we seem to have is a picture that can not be modified, sectioned, and even sometimes, measured.

I have seen all over the internet advertisements for software that can interpret and perform all kinds of things with these models, but I can't seem to find anyone associated with the softwares who actually knows how to use their own product. After speaking with the manufacturer of our CMM, I have come to find out that they, too, aren't all that knowledgeable on this type of application (yet their salesman only knew how to say that it can do all of this when we were in the process of purchasing it).

So, to make a long story even longer, basically I am looking for anyone who might have experience with this who can tell me what softwares are best for this type of application. We have customers who have parts that do not have drawings for them and need the parts to be "reverse-engineered". The ideal way to pursue this (at least in our minds) is to measure the parts on the CMM (scanning unknown shapes and features when needed) and send the 3D model of this inspection which was created by the CMM to the CAD software so that features can be analyzed and hopefully identified and dimensioned.

Can anyone offer any suggestions? :

 

[Ady12]

Re: CMM to CAD Communication

I know that the FARO software has this capability. I have breifly experimented however due to a complete lack of intrest in the capability within the wall of my company I have not pursued it any further.

Software is called CAM 2 Measure. Hope this helps.

 

[trainer]

Re: CMM to CAD Communication

Hi KosmoQA
What you are doing is called reverse engineering by taking points around your object and you need to save not as an igis file but as a DXF file.
Depending on your software you may need to take these points as ordernary single points for the file to pick up the shape.
You may be able to do it from creating a surface point or using the create profile feature.
You will have to experiment with all three to find the one that works with your software.

Good luck.

 

[EtobiLad - 2009]

So, to make a long story even longer, basically I am looking for anyone who might have experience with this who can tell me what softwares are best for this type of application. We have customers who have parts that do not have drawings for them and need the parts to be "reverse-engineered". The ideal way to pursue this (at least in our minds) is to measure the parts on the CMM (scanning unknown shapes and features when needed) and send the 3D model of this inspection which was created by the CMM to the CAD software so that features can be analyzed and hopefully identified and dimensioned.

Can anyone offer any suggestions? :

Kosmo
We do have a similar case wherein we RE the parts (automotive components) and get the point cloud created by the inspection software (our case PCDMIS). Then this probed or scanned part is converted to IGES (note no surfaces on this), then sent over to our advance engineering to analyse the points and develop the 3D solid model (using UG or CATIA).
I do not think you can directly develop from CMM using point cloud and instantly converted to 3D solid CAD format within the same environment or a software at this time to do this one step process without the separate analysis as I describe above. Unfortunately we pickup the points (there are lots, you know it) and do the long process.

 

[KosmoQA]

EtobiLab
Forgive me if I sound ignorant, but what is UG?

 

[EtobiLad - 2009]

EtobiLab
what is UG?

No problem, UG is short for Unigraphics a 3D CAD software.
We are all here to learn, glad I could help..

 

[jon_dav_uk]

Hi Kosmo

We do this kind of stuff fairly regular when reverse engineering steam turbine blades. For large complex freeform parts (i.e. 3D blade aerofoils) I would normally use a Metris LC50 laser which we have fitted to a Brown and Sharpe CMM to capture the point data. If the part is small or not so complex I will simply use the CMM softare (PC Dmis) and scan the part ensuring I get enough data so that I can create the CAD model later.

Once the data has been collected on the CMM, it needs to be transferred into a CAD package and then filtered / converted into a 3D model. The data collected by the CMM is basically point data X, Y, Z, I, J, K known as a point cloud as mentioned already by EtobiLad If we have used the laser I transfer the data into Imageware which is a CAD package with a built in point handler. I have transferred point clouds of well over 17,000,000 points in ASCII format into this software no problem. I would use this software to create all of the freeform surfaces. For geometric features I would filter the data in Imageware to a manageable size and then transfer this filtered data into ProE Wildfire where I will create all of the geometric features. I would then bring everything together in ProE and finalize the model. To verify the model against the original part for accuracy of both model creation and data capture I would then write an inspection program in PC Dmis using the model I have created and measure the original part and compare the results.

Typically the accuracy and tolerance of your parts will dictate the methods and hardware you will need. Ignoring what is said by the manufacturers of the various bits of kit out there I work to the following on the equipment I have

Metris LC50 - Accurate to 10um
SP25M Scanning Head - Accurate to 6um

Hope this helps any more questions feel free to ask

Good Luck
Jon

 

[KosmoQA]

Hi Kosmo

We do this kind of stuff fairly regular when reverse engineering steam turbine blades. For large complex freeform parts (i.e. 3D blade aerofoils) I would normally use a Metris LC50 laser which we have fitted to a Brown and Sharpe CMM to capture the point data. If the part is small or not so complex I will simply use the CMM softare (PC Dmis) and scan the part ensuring I get enough data so that I can create the CAD model later.

Once the data has been collected on the CMM, it needs to be transferred into a CAD package and then filtered / converted into a 3D model. The data collected by the CMM is basically point data X, Y, Z, I, J, K known as a point cloud as mentioned already by EtobiLad If we have used the laser I transfer the data into Imageware which is a CAD package with a built in point handler. I have transferred point clouds of well over 17,000,000 points in ASCII format into this software no problem. I would use this software to create all of the freeform surfaces. For geometric features I would filter the data in Imageware to a manageable size and then transfer this filtered data into ProE Wildfire where I will create all of the geometric features. I would then bring everything together in ProE and finalize the model. To verify the model against the original part for accuracy of both model creation and data capture I would then write an inspection program in PC Dmis using the model I have created and measure the original part and compare the results.

Typically the accuracy and tolerance of your parts will dictate the methods and hardware you will need. Ignoring what is said by the manufacturers of the various bits of kit out there I work to the following on the equipment I have

Metris LC50 - Accurate to 10um
SP25M Scanning Head - Accurate to 6um

Hope this helps any more questions feel free to ask

Good Luck
Jon

Thanks Jon, that helps tremendously! It just so happens that we are capturing our data with an SP25M, so it's good to be able to compare apples to apples.