Importing a 3d Curve

[Adamx]

Hi, just wondering if anyone knows how to import a 3d curve and which file format to use, I have tried dxf but it seems it is only for 2d objects, IGS and STL seem to be only for 3d geometry. Thanks

[Dan Petre]

which cad/cam program are you using?

iges files work fine for 3d curves, i have used it a lot in mastercam.

alternatively you can create points along splines then export those points and recreate and filter the splines.

[pvogtcharlotte]

I have done this using Rhino for the CAD file, exporting to "Parasolid" file, then importing to MasterCAM. Actually, what I had to do was create a surface to designate the elevations, then create a contour in plan view. With these two objects I use Surface Finish "project" I have an example file if this will help you.
Paul

[Dan Petre]

I am having trouble understanding your problem.

Can you explain again?

You should not need Rhino at all if you use Mastercam. Please email me the files at dan dot petre at hotmail dot com.

[justgary]

Adamx -

What CAD program are you using?

I usually don't have any problem with 3D curves in an IGES file. They normally come over as lots of line and arc segments, so don't expect them to stay grouped like they are in your CAD program.

I still can't get a point (for example, a hole center) to transfer through an IGES file. I don't know which program has the problem, but I suspect it's TurboCAD.

Try loading the attached IGES file in your CAD program and SprutCAM. You should see a hexagonal solid with a hexagonal line (six segments) and a circle at the top. If you want to post a simple file (created with your CAD program), I'll try loading it in TurboCAD to see what it looks like.

Regards,

- Just Gary

[Adamx]

Thanks heaps for your responses, I am learning inventor at the moment but use 3ds max for most 3d work as I know it very well. I am actually trying to engrave on stainless steel dog tags but the tags have a slight concaveness to them. I decided to do a manual "digitize" of the surface and got a pretty accurate 3d result in Max (I know it's not the right program for the job, but Im not up to producing 3d splines in Inventor yet..).

I then created the text to be engraved and projected it onto the surface to produce to 3d splines that I wanted to export to Sprutcam so I could use the 3d curve milling operation . I can import the model as an stl file which only has the 3d faces but no splines.

Just gary, I imported your Hex head into Sprutcam and the curves imported ok, they lie on a 2d plane.

I just tried exporting from max to an iges file and it looks like the curves have come in accurately. I am going to try and use the 3d Curve milling operation in Sprutcam to engrave. I'm pretty new to Sprutcam too so I'm not sure how it will all work.

Thanks again

[justgary]

Adamx -

Someone posted here very recently about using the "Sew" function to tell SprutCAM to make a set of lines (your engraving) lie on a 3D surface. I didn't get a chance to try it yet, but it could well be the ticket to success for you.

Look back a few posts and you will find it. I don't remember them giving very many details, but maybe you can figure out how to use the function. If you do, please post back here with your results so we don't go off and reinvent your wheel.

Even if you don't try "Sew," please post your results anyway. I don't have SprutCAM open right now, so this is from memory... One of the operations (3D Curve Milling, Engraving, etc.) is exactly what you want, but as I recall the catch is that it has offset cutting enabled by default. Select your lines and make sure that you tell SprutCAM to follow the line, not cut next to it (this would be easier to explain if I had the program open, but I'm not at the right computer for that).

You'll figure it out in only a few 30-hour debugging sessions... If not, post back here and someone will help.

Regards,

- Just Gary

[Adamx]

I think the sew command is used for joining the faces of 3d objects to make them a single object (I printed out the manual and am wading my way through it).

The default for the 2d and 3d curve milling is compensation "on" the offset output is not set as default. I ended up giving some negative stock to move the lines within the text outline to try and keep the engraved text the same size as the font which worked pretty well (I used a 0.8mm ball mill). The main difference with the 2d and 3d curve milling seems to be on the parameter tab: for 3d you need to set the "bottom offset" to indicate the lowest point the tool will travel under your 3d curve. (I set this to 0.05mm for a good engrave cut)

After all this I found that the cutter I was using was not good for engraving stainless (what is? diamond?) so I ended up making the dog tags out of good old aluminum.. At least I now know how to engrave in 3d..