Author: Gerrit Coetzee

476 Articles

Learn How A Radial Engine Works Or Gawk At Amazing Wood Model

February 4, 2016 by 19 Comments

[Ian Jimmerson] has constructed a detailed model of a radial engine out of wood and MDF for an undisclosed reason. Rather than just delivering the wooden engine to wherever wood engines go, [Ian] decided to take the time to film himself disassembling and reassembling his engine, explaining in detail how it works as he goes. He starts by teaching about the cylinder numbering and the different possible cylinder configurations. It only gets better after that, and it’s worth watching the full 20 minutes of video. You’ll leave with a definite understanding of how radial engines work, and maybe build something neat with the knowledge.

Our only complaint is the lack of build photos or construction techniques. It’s a real feat to build something with this many moving parts that can run off an electric drill. Was a CNC involved, or was he one of those hardcore guys who manage to get precision parts with manual methods? Part 1 and 2 after the break.

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Super Detailed 3d Scans With Photogrammetry

February 3, 2016 by 25 Comments

Photogrammetry is a real word, and [shapespeare] built himself a nice setup to take high-res 3d scans using it. A good set of images for photogrammetry are: in sharp focus, well lit, precisely indexed, and have a uniform background. The background was handled by a 3d printed stand and some copier paper. To get even lighting he used four adjustable LED lamps from Ikea.

In order to precisely index the object, he built an indexing set-up with an Arduino and a stepper motor (housed in the, self proclaimed, most elegant of 3d printed enclosures). The Arduino rotates the platform a measured increment, and then using [Sebastian Setz]’s very neat IR camera control library, snaps a photo. This process repeats until multiple photos of the object have been taken.

Once the photos have been taken, they need to be run through a photogrammetry processor. [shapespeare] uses Agisoft Photoscan, but says Autodesk Memento and 123d Catch do pretty well too. After all this work it appears that [shapespeare] used his new powers to 3d print a giant decking screw. Cool.

A Vase Of Ice And Fire

February 2, 2016 by 9 Comments

When we first saw [Ginko Balboa]’s vase of ice and fire, we weren’t that impressed. Until we realized that the whole vase was a glass, copper, and solder circuit with LEDs sandwiched in between. The tutorial starts with [Ginko]’s technique for etching a custom board for the base circuit. It gets interesting with the construction of the LED circuit.

First a glass bottle was scored in a pattern and shattered, leaving a jigsaw puzzle. Two differently colored LED light strips were desoldered. Then, from the bottom up, the glass was taped around with an adhesive backed copper tape, and soldered together. Every now and then an LED was soldered between the carefully separated areas of the circuit. Some LEDs were soldered in one way, and some the other. This way the vase could be rotated on its base to select a different color. Once the outside of the vase with the LED circuit inside it was finished, another cut bottle was put in the center and soldered in a final position, making the assembly waterproof.

The final product is really interesting, and we’re scratching our head to figure out if there’s anything else this technique of circuit building could be used for. Ideas?

Joysix, Six Degree Of Freedom Mouse Made From Retractable Key Rings

February 2, 2016 by 24 Comments

[Nicolas Berger] submits his six degree of freedom mouse project. He hopes to do things like control a robot arm or fly an alien mothership.

We thought the construction was really neat; suspending a wooden ball in the middle of three retractable key rings. By moving the ball around you can control the motion of a cube displayed on the computer. We first thought this was done by encoders or potentiometers measuring the amount of string coming out of the key fobs. However, what’s actually happening is a little bit cleverer.

[Nicolas] has joined each string with its own 2 axis joystick from Adafruit. He had some issues with these at first because the potentiometers in the joysticks weren’t linear, but he replaced them with a different module and got the expected output. He takes the angle values from each string, and a Python program numerically translates the output from the mouse into something the computer likes. The code is available on his GitHub. A video of the completed mouse is after the break.

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Fully Printed CNC On An IKEA Table

February 2, 2016 by 15 Comments

It seems that many 3D printer owners just aren’t getting the same buzz they used to off their 3D printers, and are taking steps to procure heavier machines. And making them in their home laboratories with, you guessed it, their 3D printers.

Following the pattern, [Michael Reitter], designed a 3D printable CNC around a IKEA MALM table. In order to span the length of the table for his X axis, he came up with a very cool looking truss assembly. The linear rails rest on top of the truss, and a carriage with the Z axis rides on the assembly. The truss has enough space in the center of it to neatly house some of the wiring. The Y-xis mounts on the side of the table.

Overall the mechanical design looks pretty solid for what it is, with all the rails taking their moments in the right orientation. We also like the work-piece hold downs that slide along the edge of the table. It even has a vacuum attachment that comes in right at the milling bit.

We’re not certain how much plastic this build takes, but it looks to be a lot. Monetarily, it will probably weigh in at a bit more than some other options. As many in the 3D printing world are discovering, sometimes there’s no reason not to leverage more mature industrial processes for lower cost large gains in accuracy and strength. Though, it’s pretty clear that one of the design goals of this project was to see how much one can get away with just a 3D printer, and we certainly can’t deny the appealing aesthetic of this CNC.

Video of it in action after the break.

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Making Parametric Models In Fusion 360

February 2, 2016 by 51 Comments

We all know and love OpenSCAD for its sweet sweet parametrical goodness. However, it’s possible to get some of that same goodness out of Fusion 360. To do this we will be making a mathematical model of our object and then we’ll change variables to get different geometry. It’s simpler than it sounds.

Even if you don’t use Fusion 360 it’s good to have an idea of how different design tools work. This is web-based 3D Modeling software produced by Autodesk. One of the nice features is that it lets me share my models with others. I’ll do that in just a minute as I walk you through modeling a simple object. Another way to describe what we’re going to learn is: How to think when modeling in Fusion 360.

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Flip Your Desktop Over To Boot Linux

February 1, 2016 by 27 Comments

[Andy France] built his computer into a Windows XP box. (Yes, this is from the past.) He needed to run windows most of the time, but it was nice to boot into Linux every now and then. That’s where the problem lay. If he was running Linux on his Windows XP case mod, he’d get made fun of. The only solution was to make a Linux sleeve for his computer. He would slide the sleeve over the case whenever he ran Linux, and hide his shame from wandering eyes. Once his plan was fully formed, he went an extra step and modified the computer so that if the sleeve was on, it would automatically boot Linux, and if it was off it would boot Windows.

The Linux sleeve could only slide on if the computer was flipped upside down. So he needed to detect when it was in this state. To do this he wired a switch into one of the com ports of his computer, and attached it to the top of the case mod. He modified the assembly code in the MBR to read the state of the switch. When the Linux sleeve is on (and therefore the computer is flipped over) it boots Linux. When the sleeve is off, Windows. Neat. It would be cool to put a small computer in a cube and have it boot different operating systems with this trick. Or maybe a computer that boots into guest mode in one orientation, and the full system in another.

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