Okuma Collision Avoidance System: Friendly STL files?

[danielm]

I'm looking for a program that will generate a more friendly .STL file that the OSP-P300MA CAS will accept.   Mastercam STL's seem to be not very compatible with the control for CAS.

I heard about a program called Space Claim...but havent tried it....

Has anyone come across this same problem?

 

Thanks in advance for any help.

DM

[mkd]

only tip i have is to export as Metric to scale correctly.

[YoDoug®]

I run into this on a daily basis. I export from Topsolid and get the invalid stl error about 50% of the time. We also have Creo here and find about the same issue. One thing that does help is having the STL-eCheck lite program from Okuma on your PC. You can check the files before you go to the machine. I think it is still a free program. There is also a version that comes with the 3DVM software that will heal bad solids. That works every time, but it is not free. 

[huskermcdoogle]

Does it happen to be related to having a hollow stl?  I have struggled with this with stock in the past with machine sim.  For some reason mastercam creates a hollow stl with stock model from time to time.

[Orvie]

There is a free utility called STL to CAS,, I think that's what it's called.

It allows you to convert, fix, orient, and reduce the number of triangles for easy import into CAS.

The P200 is limited to 3000 triangles, but the P300 can be up to 10,000 triangles.

Our machines shipped with the triangles set to zero, but this was fixed easily once I found the file that limits this.

It's been a while, but I'm pretty sure it was one of the few folders that started with the letter V.

[Colin Gilchrist]

The best software, for working with STL files, is a software called Magics RP, from a company in Belgium. It does cost a fair amount of money for a license though.

Autodesk has a free utility now, called Mesh Mixer. It does a decent job of repairing STL files.

You are probably using too fine a tolerance. The STL tolerance in Mastercam is a "chordal" tolerance. This means it is not so much an "accuracy" tolerance, as it is a 'step across the surface' distance value...

Also, if your model is a Solid, of the Machine, then you've got to "de-feature" the model.

If you have a 'surface' model, start by stitching that into a Solid body. Then, use the 'Find Features' Function  > Set to 'Remove' the feature. Remove any "holes" or other features on the Solid. Get the models down to the most primitive shape possible that you can. You want everything as simple as possible, before you try and convert it to a STL model.

You want to try and limit the amount of curved surfaces, as much as possible. When you export the STL model, the tolerance will effect the "curved" shapes the most. For something Round, that is in the Work Envelope of the machine, like a Spindle Nose, you should get very accurate results, using .04 inches (1mm) tolerance. That will give you fairly small facets on the model.

If a .040 output tolerance is to fine, try '.100', or even .250 for the STL tolerance.

When I say "de-feature", I'm talking about removing anything extra. Get rid of Chamfers and Fillets. Any unnecessary features like T-Slots. All you need to check for a Table Collision, is a rectangular block. The simplest of shapes. 6 sides, and can be represented accurately with 12 triangles. Now, add a center hole, with counterbore. And 100 threaded holes on the table, then output it with a .0005 STL tolerance, and of course it won't work with the CAS limit of 3K triangles...

Hey Orvie,

Do you happen to know if the 3K (and 10K) limits are "per model", or if they are "total # of triangles" allowed in the simulation? I thought it was a "total limit", shared amongst all the models being used, but I'm not 100% sure...

[Orvie]

20 hours ago, Colin Gilchrist said:

Do you happen to know if the 3K (and 10K) limits are "per model", or if they are "total # of triangles" allowed in the simulation? I thought it was a "total limit", shared amongst all the models being used, but I'm not 100% sure...

This number is per model.

While you can now get up to 10,000 triangles, It is much more stable to simplify things like tool locators, tailstocks, or anything that really doesn't need to be finely detailed.

[Watcher]

One thing we do with cylindrical surfaces for our WFL anti-collision systems is to extrude a polygon on their periphery like an hexagon or if necessary even more sides in order to reduce triangulation on cylindrical surfaces. It reduces triangles drastically without compromising the effectiveness of the anti-collision system.

[Brad Lisle]

Here is the STL Check-e incase anyone is looking for it. You need to output in metric (mm) and you need to have the model orientated as you want it to appear. Mastercam will typically do just fine, but you will need to adjust the output tolerance. You want as minimal triangulations as possible. As Colin stated try to dummy the model down as much as possible. Remember this is a primitive tool for simple verification only. If your model has a bunch of holes, threads, grooves, etc. that are irrelevant to the verification get rid of them. I typically try to keep them under 2000 triangles. Another issue people run into is trying to export an assembly. You can only have one model per import. The STL Check-e will verify the surfaces (triangles) and shells (models). There should be less than 3000 surfaces and only 1 shell with zero errors. Play with your export settings until you find one that works for your part. If all that fails, Space Claim works great at healing and reducing the surface count.

STLCheck-e.zip

[NOTW Programmer]

On 4/17/2018 at 9:16 PM, Brad Lisle said:

Here is the STL Check-e incase anyone is looking for it. You need to output in metric (mm) and you need to have the model orientated as you want it to appear. Mastercam will typically do just fine, but you will need to adjust the output tolerance. You want as minimal triangulations as possible. As Colin stated try to dummy the model down as much as possible. Remember this is a primitive tool for simple verification only. If your model has a bunch of holes, threads, grooves, etc. that are irrelevant to the verification get rid of them. I typically try to keep them under 2000 triangles. Another issue people run into is trying to export an assembly. You can only have one model per import. The STL Check-e will verify the surfaces (triangles) and shells (models). There should be less than 3000 surfaces and only 1 shell with zero errors. Play with your export settings until you find one that works for your part. If all that fails, Space Claim works great at healing and reducing the surface count.

STLCheck-e.zip

How do you export again? I see nothing in the menu, and save button just asks for a name.