I am interested in 3d printing for a specific application in chocolatiering...I want to create stencils that fit inside mold cavities so that I can spray color in patterns inside the mold. How complicated is it to design the piece that you want the printer to print? I've never done cad/cam before.

Unfortunately, the answer to your question is "it depends". I do a fair amount of 3d printing but I have been a draftsman for 30+ years and I'm sure I take certain things for granted.

However, if all you want to do is make a "negative" of something that will then transfer onto the surface of the chocolate, that might be pretty easy. The quick way would be to make a flat 2D "sketch" of the image and then "extrude" it to the appropriate depth. Then you would save or export the file into an .stl file or something similar. The .stl file then gets processed by slicer software (Cura is a decent freeware, meshmixer is another but I don't have much experience with it). The slicer creates gcode that is used by the 3d printer to control x,y,z movement as well as flow rate and temperature of the printer.

"Sketch" and "extrude" are the generic terms for the basic functions [commands] that most 3d software use. Sketch is just 2d drawing, extrude adds the 3rd dimension.

If you want the negative to release from the mold, you'll need to add draft angles to the extruded image (slight sloping of vertical walls). For plastic injection molds, draft angles of a fractional degree allow the part to eject from the mold. You'll need to find out the appropriate draft angle for chocolate and adjust your mold. Otherwise, you'll either destroy the chocolate trying to remove the mold or have a "permanent" mold cast into the chocolate.

Your biggest problem will probably be getting the sides smooth enough so they will release since each layer of plastic will have a slight ridge to it.. I don't have experience with it but I have heard that some of the 3d plastics can be "smoothed" by wiping with acetone or some other types of solvents. You can also play with the 3d print speed and layer thickness to get a smoother surface.

Ken

Yes. What Ken said.

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Originally posted by ChicagoSigMan:
How complicated is it to design the piece that you want the printer to print? I've never done cad/cam before.

Can you draw it with pencil/paper?
Simple designs are pretty simple, complex designs are complex & complex designs that have to interact with complex parts are a fucking nightmare - and probably won't come out printed on a cheap-ish printer anyway. small details get lost on tiny objects. Think how sloppy a hot-glue gun is - that's about what you are working with.

If you are just wanting a mask to make some lines/polka dots/stars/etc on the mold before pouring chocolate in, it may not be too bad, depending on the mold shape. I've traced, then scanned an object, then 'extruded' in a CAD program as KenS said to get a design that would fit around an odd shape.

You also need to worry about food safe plastics. Some PLA & nylon are food safe, but I wouldn't necessarily trust an unknown printer. My $400 3d printer has had some really cheap chinese filament run through it. I wouldn't trust running food safe stuff through it now.

There are also chocolate printers.

quote:

Your biggest problem will probably be getting the sides smooth enough so they will release since each layer of plastic will have a slight ridge to it..

this also presents some issues with cleaning, due to the very small grooves in the finished product. There are some printing filaments that are rated as food safe but most are not certified.