DWG changes resolution


#1

I have a drawing 15x15 cm which I exported to a dwg file. The CNC workshop imported it and strangely they see the dimension as 15x15 mm. Any ideas why this is happening?

Thanks in advance
Peter


#2

you can upload the original skp, but the issue is likey your not using…

Parallel Projection
Top View
Export 3D with unit set to cm

john


#3

Hi @john_drivenupthewall
I use the web based Shop version and couldn’t find Parallel Projection. When exporting, I selected 3D, but can’t set any units. By default Dimensions is ticked in the export dialog window.

thanks
Peter


#4

john


#5

Not sure if I had Perspective or Parallel Projection when I changed it to Top View, but the unit setting was already in cm and measurements were correct. Could the parallel projection cause the change from cm to mm?

Here is the STL for reference.Test (1).stl (84 Bytes)


#6

you may need to swap to mm for the export…

the CNC may read your cm as mm…

most 3D printers do and the web export may be aimed more to that market…

john


#7

ok, will try it and get back once I receive confirmation.


#8

if you post the dxf file here it’s easy for other to check the import units…

john


#9

I’m confused. Which are you exporting, dwg or stl? Stl is unitless; the writer and reader have to agree on what a value of 1 means. One cm or one mm? Dwg does contain units so it would be an error if the CNC isn’t reading what SketchUp set.


#10

I confused as well…

I missed the edit that added the STL file…

stl needs faces, and doesn’t need PP, but I have never used a CNC machine that doesn’t read dxf/dwg, so I assumed that was the format…

john


#11

Probably the CNC software is expecting a file that is in millimeters and you are exporting in centimeters. Try switching your modelling units to millimeters prior to exporting.

Your camera type or view has no effect to 3D model exports. Also, 3D export always uses the same units that you are currently using for modelling.


#12

in my experience it has a huge effect on the CNC operator who, more often than not, has no AC experience and perceives the file as unusable…

once set to PP the same file is accepted…

john


#13

-iirc- DXF/DWG coordinates are untiless too but dimension settings may contain the used unit… setting the destination application to the unit used by the creator prior importing should fix the issue… or simply scale afterwards by the known factor in the destination application.