Originally shared by Marcus Wolschon
Does anyone know a program that can calculate a good 2-part mold parting-line for a given geometry?
For CNC-machining molds with a minimum of manual effort.
If not, I’ll have to write one on the next train ride.
@Miguel_Sanchez
Thanks. I already have an algorithm in my head that works for me.
Do the Berkeley guys (falsely) assume that the parting line on the left and right side of a 2D cross section must be at the same height?
I don’t injection mold hard plastics, so I have no need for a minimum draft angle. This simplifies things a LOT
I reckon the left and right cross-section heights would depend on the orientation of the part.
I’d do orientation manually before starting the program. I don’t consider that part of the task of finding a waterline.
Because orientation is also affected by what size of stock material you have, what cutter lengthes you have, …
I created the framework and can successfull load a large STL file, and display it’s content.
Now I need to implement the actual parting-line algorithm and have it create geometry for 2 blocks (upper+lower stock) that meed at this parting line. In a third step I can then implement a boolean operation to create closed polygon models for upper and lower (negative) mold and export these 2 into separate files for machining.
I have existing proof of concept code for simultanous 4,5 and 6 axis milling.
That code includes loading an ASCII STL, displaying 3 parallel projections and data structures for storing the polygon data.
It’s exactly what I need as a starting point for this simple, little tool.
Laserweb looks like something for laser cutting.
This however only makes sense on a 3 axis milling machine that can be used to mill the rest of the mold, alignment pins and holes for fasteners in a chained g-code operation.
@Marcus_Wolschon LaserWeb also has CNC features in v3 and the v4 in dev will be a MAJOR release for this matter (and all the others too). Please have a look dev posts from the last two month to have a taste of what’s coming and of the amazing dev crew at work. Eventualy talk to grand master +Peter van der Walt and/or CNC coding guru @Todd_Fleming to get deeper insights
If I integrated into a cad, I think the one I use (Geomagic via API) or FreeCAD would be a better choice.
@Marcus_Wolschon @FreeCAD please for a CAD integration 
A mold making workbench would be à great addition to the range !
But having it down the road in the CAM tool allows every one to use it’s CAD of choice
I had an other look at it. The CNC support of laser web is for 2.5D ENGRAVING. This calculation only makes sense for a CAD program (not a CAM) for 3D milling. Your suggestion doesn’t make sense. How would I even load a 3D geometry of the master and export the calculates geometries of the two blanks?
@Jeremie_Tarot you have to import the calculated blanks into a CAD, add registers and fasteners, subtract the master,… That can’t be done in a CAM. I know the FreeCAD code and the language used as well as the code structure. It would be make this a 2 month project instead of a single day. But after testing and documenting the algorithm, it’s easy to re-implement.
If there is an existing mold making workbench, I may add it at a later time. I’m also waiting for they CAM2 workbench to become complete and stable enough to add my 6 axis code as a ToolPathGenrator.
After New Year I’ll finish this standalone app. If it works, I’ll make it more user friendly and self-explanatory and add a proper documentation of the usage and algorithm.
ACK
