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Comment by lvh | Hacker News Reader

Something I really want is the ability to write code to produce exact curves exportable via STEP, so I can get them into Fusion 360, which is what most CNC (e.g. the Shopbot PRS Alpha) prefers to consume. Imprecise polyhedra approximations are fine if you're 3D printing, but subtractive methods like CNC routers can do orders of magnitude smaller features. Bumping up the precision is just kicking the can down the road, also, most CAM software will just roll over and die if you give it shapes with massive polycounts, while it'll trivially handle the BRep version of the underlying shape (which might be a simple set of splines for example).

So far OpenCASCADE is the most promising library I've found. And it's been around for a long while: I don't remember the last time I had to tell bindgen about the "DECOSF1" macro!

And of course AutoCAD, but this is a hobby and I don't feel like spending thousands :-)

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I have an issue with the third party CAM software we bought where it’s stuffing up the G-code in a way the OEM software doesn’t.

I create writing in Inkscape and save as DXF, then open in DraftSight, scale correctly, an other detail (outline, holes, etc).

Inkscape creates a DXF file with a whole lot of splines. The OEM CAM software is ok with this. The new third party app is creating overly complex G-code that causes our laser cutter to pause briefly at some of the end / beginning of the splines, which results in huge heat input and the stainless steel parts look terrible with small discolouration at the pauses.

I’m trying to find alternative methods of creating text, but I don’t know the space very well.

Maybe I need a different CAD or vector graphics app that can create letters with fewer objects?

AutoCAD has an explodetext command, but it creates completely useless outlines that look a mess. DraftSight’s same commsnd results in text outlines that are comprised of hundreds of small straight lines, also useless.

Any ideas?

Does the text retain its approximate shape if you use Inkscape's Simplify command to reduce the number of control points? And then does that actually affect the DXF output?

So, I've been sitting at my work computer for, what?, 4 years with QCAD and FreeCAD installed and have never thought to try either of these.

Going to give that a go today, just got to work at 05:40 so will let you know how I go later.

FYI, 05:40 is every hour.

Is this a reference to something? Not sure what you mean here.

Without a time zone the time of day is meaningless.

Have you tried cadquery [1]? It can do what you want and I think it's superiour to OpenSCAD in every way. It uses OpenCascade under the hood.

[1] https://github.com/CadQuery/cadquery

Just to add another tool to this discussion, I have had great success using Eyeshot by DevDept as a programmable CAD platform for .NET. Its closed source and a bit pricey but it was simpler and quicker to integrate with my commercial CAD/CAM product than OpenSCAD or an OpenCASCADE derivative and their support over the years has been responsive. They also include a STEP/IGES import export routine in their higher end offering. http://www.devdept.com

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