When The Right Tool Is Wrong

I’m a firm believer in using the right tool for the job. And one of the most fantastic things about open-source software tools is that nothing stops you from trying them all. For instance, I’ve been going back and forth between a couple, maybe three, CAD/CAM tools over the past few weeks. They each have their strengths and weaknesses, and so if I’m doing a simpler job, I use the simpler software, because it’s quicker and, well, simpler. But I’ve got to cut it out, at least for a while, and I’ll tell you why.

The first of the packages is FreeCAD, and it’s an extremely capable piece of CAD/CAM software. It can do everything, or so it seems. But it’s got a long shallow learning curve, and I’m only about halfway up. I’m at the stage where I should be hammering out simple “hello world” parts for practice. I say, I should be.

Fortunately/unfortunately, some Hackaday readers introduced me to KrabzCAM through the comments. It’s significantly less feature-full than FreeCAD, but it gets the job of turning your wife’s sketches of bunnies into Easter decorations done in a jiffy. For simple stuff like that, it’s a nice simple tool, and is the perfect fit for 2D CAM jobs. It’s got some other nice features, and it handles laser engraving nicely as well. And that’s the problem.

Doing the simple stuff with KrabzCAM means that when I do finally turn back to FreeCAD, I’m working on a more challenging project — using techniques that I’m not necessarily up to speed on. So I’ll put the time in, but find myself still stumbling over the introductory “hello world” stuff like navigation and project setup.

I know — #first-world-hacker-problems. “Poor Elliot has access to too many useful tools, with strengths that make them fit different jobs!” And honestly, I’m stoked to have so many good options — that wasn’t the case five years ago. But in this case, using the right tool for the job is wrong for me learning the other tool.

On reflection, this is related to the never-try-anything-new-because-your-current-tools-work-just-fine problem. And the solution to that one is to simply bite the bullet and stick it out with FreeCAD until I get proficient. But KrabzCAM works so well for those small 2D jobs…

A hacker’s life is hard.

Use Nodes To Code Loads Of G-code For 3D CNC Carving

Most CNC workflows start with a 3D model, which is then passed to CAM software to be converted into the G-code language that CNC machines love and understand. G-code, however, is simple enough that rudimentary coding skills are all you need to start writing your very own programmatic CNC tool paths. Any language that can output plain text is fully capable of enabling you to directly control powerful motors and rapidly spinning blades.

[siemenc] shows us how to use Grasshopper – a visual node-based programming system for Rhino 3D – to output G-code that makes some interesting patterns and shapes in wood when fed to a ShopBot. Though the Rhino software is a bit expensive and thus is not too widely available, [siemenc] walks through some background, theory, and procedures that could be useful and inspirational no matter what software or programming language you’re using to create your bespoke G-code.

For links to code and related blog posts, plus more lovely pictures of intricately carved plywood, check out [siemenc]’s personal site as well.

[via Bantam Tools]

4 Axis Delta Router Says Hello World


[Bart] stood upon the shoulders of the delta 3D printer giants and created this 4 axis delta router. The router was originally created for ORD Camp, an invite only hackers gathering. Each year he creates a new thing with one main purpose: to spark conversation. In his own words “Practicality and suitability are way down the list, so go ahead and snark away. If you do, you are missing the point.”

[Bart] did things a bit differently with his delta. For motors, he went with non captive steppers. “Non captive” means that rather than a shaft, the motor has a hollow threaded nut which rotates. A lead screw (usually with an acme thread) is passed through this nut. As the motor’s nut turns, the screw is pushed or pulled through the motor, creating a linear actuator. The only major downside is that a non captive stepper motor can’t be adjusted by hand. The screw doesn’t turn and neither do any external parts of the motor. For structure, the router uses MakerSlide and v-grove wheels. The spindle is a simple brushless hobby motor and 30 amp speed control. Rather than the outrunner motors we’ve seen lately, [Bart] wisely chose an inrunner motor normally used on R/C cars. Inrunners generally have less torque than their outrunner counterparts, but they make up for this in RPM. [Bart’s] motor is capable of 30,000 RPM, which is plenty for spindle duty. We think the motor bearings will probably need an upgrade, as the original motor bearings weren’t designed for side loads. For a controller, [Bart] utilized an  Azteeg X3 running Repetier.

The router made a great showing at camp, and [Bart] decided it needed a 4th axis. He sourced a rotary axis from eBay. To keep the software simple, he connected the rotary axis to the extruder outputs on his controller. He was then able to hack the mach3 wrapped rotary post processor to output extruder commands. The results look great. [Bart] says the system definitely needs a tailstock, and we agree. We’re looking forward to the next update on this machine!

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