Grasshopper & CAD workflow

Hi all,
I am trying to develop an efficient workflow to create the base geometry of my projects (small furniture) parametrically in a CAD program (I am trying Alibre Atom atm, affordable yet functional enough for my needs and I just cannot get the flow with freecad) and do the embellishments in Rhino/grasshopper.

What is a good way to combine these workflows? Convert a 3d model to drawings and import them in Rhino (dwg)? Or do you import the whole model and work from there? Which format do you use? The parts of the assembly need to be laid down for laser cutting, how would you approach that in Rhino? Project them?

Thanks!

Hi Terribel, Can you post a small example of the incoming geometry and the eventual desired output? Thanks

I typically use STEP (or sometimes IGES) to move cad beween Rhino and other CAD programs.

Just bear in mind that you don’t need to explicitly work on the CAD you bring into Rhino from elsewhere. I typically export a STEP from a cad package into Rhino then create a surface in Rhino that approximates very closely the part of my geometry I want to work with. Do the stuff in Grasshopper, bake the geometry and export just that Rhino-created geometry as a STEP file and import it back into my CAD software and use it to cut or add etc. to the geometry.

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Hi,

I was out of town for a few days.
Sure. For example this piece:

This has been an ongoing topic. I created the geometry in full in GH as well (see this topic: Grasshopper - Workflow) but it is not a practical workflow for me (yet). As suggested in that topic, it might be a better approach to combine parametric CAD with RHino/GH. Hence my question. This is maybe too simple an example to bother making it parametric (takes 5 min probably to adapt in Rhino), but I would like to develop a consistent and fast approach for more complex projects, too. Say:

but with more complex geometric patterns.

I think it would come down to:

  1. design parametric 3D model in CAD
  2. flatten to 2D
  3. Add geometric patterns, embellishment,…in GH

to be defined what takes place in Alibre and what in Rhino/GH…
e.g I could create 2D drawings from the 3D model and import them in Rhino, but maybe it makes more sense to import the 3D model in Rhino and generate the 2D views from them using GH.

Just trying to work out an efficient workflow that allows rapid iteration of such more complex designs. The result is used for laser cutting/CNC milling.

There are possibly many ways to do this, was just wondering how others approach this…Thank you for your insights!

Hi,

(i’ll try to be brief)

Please forgive me for not sharing the code. It’s a pro-project.

I use 99% GH to design what to CNC/Laser/etc later. For the reasons you mentioned.

Once my GH model is defined, I can easily orient, move the parts to the cnc bed plane to optimize the least wood usage. Also it’s made to make it easiest to select the parts in the cam interface.

I use RhinoCAM and they ‘started’ making GH components (Very alpha)… So all this time investment to prep for the cnc using curve selections might hopefully be a thing of the past soon.

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Thanks for your answer.

I worked on a similar project not too long ago:

GH works like a charm for this kind of geometry. I see no reason to use a parametric CAD program for such projects.
Imho it is a different story for e.g furniture or technical stuff, which is at conception an assembly of several parts. The definition for the piece I posted earlier is very big, and mainly consists of selecting the right edges and repeating the same sequence of components with slightly different settings for each face. Seems to me that a parametric CAD package is better at that. Therefore, I am looking for inspiration on how to combine these two packages…

Hi, that’s interesting, thanks! Would you then add constraints to the imported geometry? which CAD package do you use?

Thanks!

I use creo (well, an older version when it was still pro/e wildfire). When I import the Rhino-created geometry back into creo I reference it to a co-ordinate system I can move around which then moves the geometry around, but it’s typically unnecessary as I’ve already correctly placed it in Rhino. Vast majority of the time this work is done near the end of the design with no critical part of the design dependent on (or referenced to) the Rhino-imported geometry. If I need to make change I do the work in Rhino and re-import into creo - haven’t found a way to seamlessly link the files between the two programs.

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This project I used input curves from rhino, and the rest I built in grasshopper:

I can quickly make variations of this design simply by changing input curves and changing a few parameters in grasshopper.



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I do also other non-sliced work with GH… I pickup the guitar shapes needed and now can vary any part to be cnc’ed…

Not the simplest program but it’s finally there… Took about 3-4 months to do in my spare time… 2 weeks time to model the body, head and bottom of the neck, frets. The neck interfaces took a lot lot longer. So in a typical CAD environment this might not fly compared to a skilled CAD user.

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