fastcam recognizes circles as polygons

Yeison Jahir Riveros Ortiz shared this question 7 months ago
Need Answer

fastcam recognizes curves as small connecting lines, therefore the cut is not smooth in circles and curves. Thanks for the help

I work with the Corel Draw program for the vectorization of images and cutting patterns in CNC Plasma, in the design range the curves look good, just like when I export to DXF, I review in AUTOCAD and the splines look good and with the curvature, when I insert it into fastcam to generate the g code, the circles and curves look polygonal

Comments (1)

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Are you working with FastCAM7 or FastCAM8?


In FastCAM8 there is selection of coarse / standard / fine conversion of splines.

In FastCAM7 it is just one fixed level of conversion.


As you have AutoCAD, you can also investigate the AutoCAD feature to explode and break the spline object into lines + arcs.

regards

Jackson

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Trabajo con fastcam 7, cuando hago los diseños en autocad se ven bien las curvaturas pero cuando solo voy al fastnet de fascam para generar el código me salen las curvas representadas por muchas rectas. gracias por la atención me estoy iniciando en el corte por plasma cnc.
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That is the limitation in FastCAM7 support for polylines.

As suggested, you will need to use AUTOCAD to EXPLODE these polylines first.

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Please send through the DXF file in question from the above image and we will check it here.

In FastCAM 7 you do have the option to perform a CAD Compress as well, which will then take all short line movements and compress them into longer lines or arcs where possible.

https://response.fastcam.com/knowledge-base/article/how-to-use-cad-compress

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How can I send the file, when I click attach I get an error "wrong dxf file" Thank you, I will follow the instructions on the page.

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Perform the steps it says to compress DXF and reduce the number of entities but it does not provide a solution. What it does is lengthen the lines and they are not crossed, only polygons are formed with fewer sides and longer lengths.
It will be learning how to use autocad to see if I solve the problem

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You can try attaching a ZIP file of the DXF, or if that fails, please email the file to fastcam@fastcam.com.au.

If after compression the drawing is still 'jagged' in appearance then perhaps your compress values were too large. We can assist with this if we can get a copy of the file.

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En autocad cambio las polilineas a curvas y pues el diseño se ve bien ya cuando lo paso al fastnet7 de fastcam ya el diseño no queda co las curvas suaves si no con muchas lineas pequeñas. ademas en autucad salen poco nodos y cuando los paso para el anidado me genera muchos a una linea o curva y eso afecta demasiado a la calida del corte y tambien no se que posprocesador utiliza fastnet, tampoco sale para actualizar a la version 8. que precios se tiene para la version 8 y si en realida me corrigue ese error

Files: P.rar
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I have checked through the 2 files provided and using FastCAM v7 and the CAD Compress function I can reduce the total number of entities by a factor of around 80% and still maintain the original shape without much deviation.

For example the file - "patron faltante.dxf" starts off with 6649 Entities.

After I preform a CAD Compress using 10mm and the Line Length and 0.1mm as the deviation, I end up with 999 Entities and the Shape of the drawing is still the same.

Here is the same section as you had posted above, after I had done my compress.


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Your end goal is to produce NC Code for the cutting machine, but you need to remember that the cutting machine can only use Straight Line and simple Arc commands. The machines cannot handle or understand Splines.

That us why when we read n a spline we initially convert it to short straight lines segments. From there you can perform a compress which will (where possible) convert them into longer straight lines or Arcs. That way you can then output code for the machine.

For the other file - "panel libelulas.dxf" I used Compress values of 4 for the Line Length and 0.1 for the deviation.

As this second drawing is a lot more detailed you still end up with a fair amount of entities, around 5000 but that is to be expected due to the detail of the drawing.

Please try the CAD Compress function in FastCAM with the settings I used and see the results.

I have also attached the compressed DXF files as well for your viewing.

FastCAM 8 and the behavior of reading/converting Splines works in the same way as v7. there is one new feature however that allows you to decide on the level of detail for the Spline conversion during the file-open, but other than that the method and steps are still the same.

The FastCAM 8 prices can be found here - https://secure.fastcam.com/solo/products/Product.aspx?ProductID=29800

FastCAM 8 can use the same Post Processor files that you current v7 uses, so there is no issue in upgrading at anytime.

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Here are the Compressed files.

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