Rhino5 file written from Rhino7 does not open in MasterCam

As per title, we’re using MasterCam (version 2020) in the model making 5-axis milling machine, and a Rhino5 file written from Rhino7 does not open in MasterCam. Opening this file in Rhino6 (or Rhino5) and saving it again in Rhino5 format solves this problem.

Is this a known issue? We’re using 7 SR4 at the moment.

Hi @menno,

I’m not a MasterCam user, but I’ve messed with .3DM file versioning a bit. R7 seems to put the right file version in the file; as far as I know the only thing that is R7-specific is the application name. So my guess is that MasterCam is looking for an application name of Rhinoceros 5.n or Rhinoceros 6.n (n being an integer) and doesn’t cater for Rhinoceros 7.n yet. Saving the file originating in R7 from R5 or R6 is overwriting the application name, making it acceptable.

You could test this hypothesis by using a hex editor to change the application name version from 7.4 to 5.0 - you will find it near the start of the file:

If that makes the file readable in MasterCam you can ask them to accept 7.n values (and maybe 8.n?) or restrict their checking to the Archive Version (the 50 value).


p.s. These properties should normally be accessed through RhinoCommon or OpenNurbs - the position in the file is not guaranteed to remain consistent.

Ok, cool that is something to try.