Portmanteau Spewing PunBot

December 26, 2018 by Brian McEvoy 9 Comments

When Python was created, [Guido van Rossum] knew that one day it would be fully realized and take its final form. Clearly, that day has arrived since there now exists a way to send a word query and receive a lengthy list of potential portmanteaus. Some may regard this as merely quaint, but it will be the most important thing to happen in binary until the singularity.

Perhaps we are overpromising a smidge, but it may be fun to spend an afternoon getting your own whimsicalibrated pun resource churning out some eye-roll-worthy word combos. The steps are broken up neatly and explained at a high level with links for more in-depth explanations so a novice can slog through it, but a whiz can wrap it up while the boss is looking the other way.

We truly live in the future, but we may continue writing our own brand of artisanal puns which are number one in someone’s book.

Young Entrepreneurs Learn What Really Goes Into Making A Product

December 15, 2018 by Donald Papp 7 Comments

Just to be clear, the primary goal of the Papas Inventeurs (Inventor Dads) was to have the kids make something, have fun, and learn. In that light, they enjoyed a huge success. Four children designed, made, and sold laser-cut napkin rings from a booth at the Ottawa Maker Faire as a fun learning process (English translation, original link in French.) [pepelepoisson] documented the entire thing from beginning to end with plenty of photos. Things started at proof of concept, then design brainstorming, prototyping, manufacture, booth design, and finally sales. While adults were involved, every step was done by the kids themselves.

It all began when the kids were taken to a local fab lab at the École Polytechnique and made some laser-cut napkin holders from plywood for personal use. Later, they decided to design, manufacture, and sell them at the Ottawa Maker Faire. Money for the plywood came from piggy banks, 23 different designs made the cut, and a total of 103 rings were made. A display board and signs made from reclaimed materials rounded out the whole set.

In the end, about 20% of people who visited and showed interest made a purchase, and 60 of the 103 pieces were sold for a profit of $126. Of course, the whole process also involved about 100 hours of combined work between the kids and parents and use of a laser cutter, so it’s not exactly a recipe for easy wealth. But it was an incredibly enriching experience, at least figuratively, for everyone involved.

Possibly the biggest takeaway was the way manufacturing involved much more than just pressing “GO” on a laser cutter. Some pieces needed sanding after laser cutting, and each piece got two coats of varnish. If you missed it, [Bob Baddeley] showed how labor, and not materials, ends up being the most expensive part of a product.

Build Your Own Anechoic Chamber

December 14, 2018 by Bryan Cockfield 16 Comments

For professional-level sound recording, you’ll need professional-level equipment. Microphones and mixing gear are the obvious necessities, as well as a good computer with the right software on it. But once you have those things covered, you’ll also need a place to record. Without a good acoustic space, you’ll have all kinds of reflections and artefacts in your sound recordings, and if you can’t rent a studio you can always build your anechoic chamber.

While it is possible to carpet the walls of a room or randomly glue egg crate foam to your walls, [Tech Ingredients] tests some homemade panels of various shapes, sizes, and materials against commercially available solutions. To do this he uses a special enclosed speaker pointed at the material, and a microphone to measure the sound reflections. The tests show promising results for the homemade acoustic-absorbing panels, at a fraction of the cost of ready-made panels.

From there, we are shown how to make and assemble these panels in order to get the best performance from them. When dealing with acoustics, even the glue used to hold everything together can change the properties of the materials. We also see a few other cost saving methods in construction that can help when building the panels themselves as well. And, while this build focuses on acoustic anechoic chambers, don’t forget that there are anechoic chambers for electromagnetic radiation that use the same principles as well.

Thanks to [jafinch78] for the tip!

Continue reading “Build Your Own Anechoic Chamber” →

A Lecture By A Fun Guy

December 14, 2018 by Brian McEvoy 9 Comments

Many people hear “fungus” and think of mushrooms. This is akin to hearing “trees” and thinking of apples. Fungus makes up 2% of earth’s total biomass or 10% of the non-plant biomass, and ranges from the deadly to the delicious. This lecture by [Justin Atkin] of [The Thought Emporium] is slightly shorter than a college class period but is like a whole semester’s worth of tidbits, and the lab section is about growing something (potentially) edible rather than a mere demonstration. The video can also be found below the break.

Let’s start with the lab where we learn to grow fungus in a mason jar on purpose for a change. The ingredient list is simple.

2 parts vermiculite
1 part brown rice flour
1 part water
Spore syringe

Combine, sterilize, cool, inoculate, and wait. We get distracted when cool things are happening so shopping around for these items was definitely hampered by listening to the lecture portion of the video.

Continue reading “A Lecture By A Fun Guy” →

Lessons Learned From A 1-Day RTL-SDR Enclosure Project

December 14, 2018 by Donald Papp 9 Comments

[ByTechLab] needed an enclosure for his R820T2 based RTL-SDR, which sports an SMA connector. Resolving to design and 3D print one in less than a day, he learned a few things about practical design for 3D printing and shared them online along with his CAD files.

The RTL-SDR is a family of economical software defined radio receivers, and [ByTechLab]’s’ enclosure (CAD files available on GrabCAD and STL on Thingiverse) is specific to his model. However, the lessons he learned are applicable to enclosure design in general, and a few of them specifically apply to 3D printing.

He started by making a basic model of the PCB and being sure to include all large components. With that, he could model the right voids inside the enclosure to ensure a minimum of wasted space. The PCB lacks any sort of mounting holes, so the model was also useful to choose where to place some tabs to hold the PCB in place. That took care of the enclosure design, but it also pays to be mindful of the manufacturing method so as to play to its strengths. For FDM 3D printing, that means most curved shapes and rounded edges are trivial. It also means that the biggest favor you can do yourself is to design parts so that they can be printed in a stable orientation without any supports.

This may be nothing that an experienced 3D printer and modeler doesn’t already know, but everyone is a novice at some point and learning from others’ experiences can be a real timesaver. For the more experienced, we covered a somewhat more in-depth guide to practical 3D printed enclosure design.

[ByTechLab]’s desire for a custom enclosure was partly because RTL-SDR devices come in many shapes and sizes, as you can see in this review of 19 different units (of which only 14 actually worked.)

Generating Power With Wind, Water, And Solar

December 9, 2018 by Al Williams 22 Comments

It is three weeks after the apocalypse. No zombies yet. But you do need to charge your cell phone. How do you quickly make a wind turbine? If you’ve read this project, you might reach for a few empty water bottles. This educational project might not charge your phone without some extra work, but it does illustrate how to use water bottles to make a workable air scoop for turning a crank and possibly generating electricity.

That takes care of the wind and water aspects, but how did we get solar? According to the post — and we agree it is technically true — wind power is a form of solar power since the wind is driven by temperature differences created by the sun. Technically true!

Continue reading “Generating Power With Wind, Water, And Solar” →

Your BOM Is Not Your COGS

December 6, 2018 by Bob Baddeley 83 Comments

“The prototype was $12 in parts, so I’ll sell it for $15.” That is your recipe for disaster, and why so many Kickstarter projects fail. The Bill of Materials (BOM) is just a subset of the Cost of Goods Sold (COGS), and if you aren’t selling your product for more than your COGS, you will lose money and go out of business.

We’ve all been there; we throw together a project using parts we have laying around, and in our writeup we list the major components and their price. We ignore all the little bits of wire and screws and hot glue and time, and we aren’t shipping it, so there’s no packaging to consider. Someone asks how much it cost, and you throw out a ballpark number. They say “hey, that’s pretty reasonable” and now you’re imagining making it in volume and selling it for slightly higher than your BOM. Stop right there. Here’s how pricing really works, and how to avoid sinking time into an untenable business.

Continue reading “Your BOM Is Not Your COGS” →