3D modelling

10 Articles

Ditch OpenSCAD For C++

January 3, 2017 by 64 Comments

There’s an old saying that a picture is worth a thousand words. If you’ve ever tried to build furniture or a toy with one of those instructions sheets that contains nothing but pictures, you might disagree. 3D design is much the same for a lot of people. You think you want to draw things graphically, but once you start doing complex things and making changes, parametric modeling is the way to go. Some CAD tools let you do both, but many 3D printer users wind up using OpenSCAD which is fully parametric.

If you’ve used OpenSCAD you know that it is like a simple programming language, but with some significant differences from what you normally use. It is a good bet that most Hackaday readers can program in at least one language. So why learn something new? A real programming language is likely to have features you won’t find readily in OpenSCAD that, in theory, ought to help with reuse and managing complex designs.

I considered OpenJSCAD. It is more or less OpenSCAD for JavaScript. However, JavaScript is a bit of a scripting language itself. Sure, it has objects and some other features, but I’m more comfortable with C++. I thought about using the OpenCSG library that OpenSCAD uses, but that exposes a lot of detail.

Instead, I turned to a project that uses C++ code to generate OpenSCAD output, OOML (the Object Oriented Mechanics Language)). OpenSCAD does the rendering, exporting, and other functions. Unfortunately, the project seems to have stalled a few years back and the primary web-based documentation for it seems to be absent. However, it is very usable and if you know how to find it, there is plenty of documentation available.

Why not OpenSCAD?

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Up Your CAD Game With Good Reference Photos

May 6, 2016 by 28 Comments

I’ve taken lots of reference photos for various projects. The first time, I remember suffering a lot and having to redo a model a few times before I got a picture that worked. Just like measuring parts badly, refining your reference photo skills will save you a lot of time and effort when trying to reproduce objects in CAD. Once you have a model of an object, it’s easy to design mating parts, to reproduce the original, or even for milling the original for precise alterations.

I’m adding some parts onto a cheap food dehydrator from the local import store. I’m not certain if my project will succeed, but it’s a good project to talk about taking reference photos. The object is white, indistinct, and awkward, which makes it a difficult object to take a good photo for reference use in a CAD program. I looked around for a decent tutorial on the subject, and only found one. Maybe my Google-fu wasn’t the best that day. Either way, It was mostly for taking good orthogonal shots, and not how to optimize the picture to get dimensions out of it later.

There are a few things to note when taking a reference photo. The first is the distortion and the setup of your equipment to combat it. The second is including reference scales and surfaces to assist in producing a final model from which geometry and dimensions can be accurately taken. The last is post-processing the picture to try to fight the distortion, and also to prepare it for use in cad and modeling software.

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Hackaday Links: October 18, 2015

October 18, 2015 by 9 Comments

We have our featured speakers lined up for the Hackaday Supercon, one of which is [Fran Blanche]. We’ve seen a lot of her work, from playing with pocket watches to not having the funding to build an Apollo Guidance Computer DSKY. In her spare time, she builds guitar pedals, and there’s a biopic of her in She Shreds magazine.

Halloween is coming, and that means dressing children up as pirates, fairies, characters from the latest Marvel and Disney movies, and electrolytic capacitors.

There’s a new movie on [Steve Jobs]. It’s called the Jobs S. It’s a major upgrade of the previous release, featuring a faster processor and more retinas. One more thing. Someone is trying to cash in on [Woz]’s work. This time it’s an auction for a complete Apple I that’s expected to go for $770,000 USD.

Hackaday community member [John McLear] is giving away the factory seconds of his original NFC ring (think jewelry). These still work but failed QA for small reasons and will be fun to hack around on. You pay shipping which starts at £60 for 50 rings. We’ve grabbed enough of them to include in the goody bags for the Hackaday Superconference. If you have an event coming up, getting everyone hacking on NFC is an interesting activity. If you don’t want 50+, [John] is also in the middle of a Kickstarter for an improved version.

Your 3D printed parts will rarely come out perfectly. There will always be some strings or scars from removing them from the bed. There’s a solution to these problems: use a hot air gun.

Everyone has a plumbus in their home, but how do they do it? First, they take the dinglebop, and smooth it out with a bunch of schleem. The schleem is then repurposed for later batches.