- Build all files to
theoreticalsunless you are confident in your modeling
skills. Poor surface development from incorporating fillets and radiuses are the main cause for gaps when attempting to stitch files.
- When creating files (parts that will be assembled) remember to include design clearances. If you create your files line for line they will not fit together. For items that will require painting about .010-.012” per side should be sufficient. If pieces will be assembled with light sanding only approximately .005-.008” design clearance will be required.
- When creating part geometry small details will be filled during painting. Design these areas to allow for paint buildup to maintain the desired finished appearance. In other words, make them deeper.
- Same folder/file naming conventions as rapid prototyping.
- All extra geometry must be removed (double surfaces, construction
geometry and curves unless they are cut lines)
- Organize file – All surface data must reside on one or more layers, cut
lines must be on one separate layer (no surface data).
- Many files contain blanked entities that are not required, delete all of this geometry to reduce file size thus reducing tool path generation
time Makesure the scale of your file is correct!
File structure/name conventions – example for submitting CNC.IGES
Create Folder: student’s first and last name – Trans/Prod/ID/ etc.
Create IGES file: John-Doe-car,cellphone,boat,ect..IGES
Saving an IGES File in Alias for CNC Machining
- MAKE SURE MODEL IS SCALED CORRECTLY
- Select all
- File – Export – Active as (click square icon) – File formats –
- Set output units to whatever units you built the model in (i.e. if
you built model in inches, set to inches etc.)
- Click next, save where you want it.
Saving an IGES File in Rhino for CNC Machining
- Set file tolerances prior to building model
- Set file tolerances under the UNITS settings:
- Absolute .001 units
- Relative .01 percentage
- Angle .1 degree
- Select object
- Save as – IGES (*.igs)
- IGES Export Options – Detailed controls
- Set IGES type to – Mastercam
- Double Check IGES tolerance is set to .001
- Click OK
Finishing of CNC Machined Files
- For parts produced from the CNC machine – light cleanup and
sanding will need to be performed before any primer is applied.
- Files milled using 20lb. foam will require at least two coats of
primer before painting.