Making a tiny audio system for our cooler (part 1)

I’m selecting components for the audio cooler that I’m going to build. The components need to be tiny to fit in the coolers lid

Introduction

For picknicks we use a small cooler and with the upcoming spring and summer it seems like a great idea to add an audio system to it. Most DIY coolers with audio that I found on the internet are huge. Not only do they have large speakers and amplifiers but they also have a huge lead battery hardly leaving any space for the picknick gear. I want a tiny, one speaker system that sounds nice but is lightweight and leaves plenty of room for the other stuff. I also wanted it nicely integrated in the cooler without too many wires. I therefore started to design and build one.

Choosing the audio components

I started this project by choosing a suitable battery. As stated above lead batteries are relatively large due to their low energy density. Lithium polymer batteries on the other hand have large energy density, four to five times higher than lead according to this source. Prices of polymer batteries are also very reasonable nowadays.

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Lead-acid battery (left) and polymer battery (right) side by side on the small cooler. The much bigger and heavier lead-acid battery has a capacity of 5000mAh (6V) while the lithium polymer battery has 1200mAh (3,7V). The lithium polymer with it’s four to five times larger energy density is therefore perfect for my small audio system.

Continue reading “Making a tiny audio system for our cooler (part 1)”

OpenELEC maintenance

How to update OpenELEC without loosing settings, getting YouTube to work again and creating an OpenELEC backup. Make screenshots in OpenELEC.

Introduction

last year I built a PC especially for OpenELEC. For those of you who don’t know, OpenELEC is a Linux based system with the sole purpose to run Kodi, the all-in-one solution to play all media you throw at it. Because of this sole purpose OpenELEC is very fast, especially on the Intel based system that I built, and very reliable. Over time however some maintenance of the system is necessary to keep the system up-to-date and fully functional. Continue reading “OpenELEC maintenance”

More designing and 3D printing

putting my 3D printer to use

Introduction

The last couple of weeks I’ve been busy mastering 3D modeling programs and bringing my creations to life with my Hephestos 3D printer. In this entry I’ll share some of my creations and how they were made. For 3D modeling I started with OpenSCAD in the beginning of this year and later started using FreeCAD. The reason for using FreeCAD is that with more complex design in OpenSCAD it is easy for me to get lost in a large script. Yes, the learning curve of FreeCAD is steep but eventually it’s easier for me to create more complex models in this program than in OpenSCAD. For simpler models I still like OpenSCAD better. Continue reading “More designing and 3D printing”

Case for a FM-radio (Velleman MK194)

Making good use of a 3d printer

I have a MK194 radio kit from Velleman and turned it into a radio someĀ  time ago. The radio looks pretty cool with all the electronic components visible but the wooden case was awful. I therefore decided to build a new case for it. Of course I want to use my Hephestos 2 printer from BQ to make this case.

First I designed a case in FreeCAD. I use FreeCAD for a couple of weeks now, together with OpenScad, but this is the first design with multiple parts that I create with it. After several iterations I finally decided to have a design consisting of three parts. A box, a support plate for the radio PCB and a lid. The radio fits into the support and the lid which are then screwed onto the box.

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Design for the radio case made with FreeCAD consisting of three parts (the red part just represents the MK194 PCB). I made a nice radius on the lid and the MK194 fits nicely between the support and the lid.

Continue reading “Case for a FM-radio (Velleman MK194)”

Blogger vs WordPress

Should I move my blog from Blogger to WordPress.

My sister asked me to create a website for her business. In all honesty, it’s been some time since I last made a website so I did some research before I started. I quickly found out that WordPress is now the dominating platform or content management system (CMS) as it is called. It’s also completely open source (GPL license) which is a big bonus for me. It therefore didn’t took me long to decide to use WordPress for the website.

While working with WordPress I was impressed by it’s the ease of use and the huge number of themes. Also the support on the internet is excellent. So I began asking myself if I should move my blog from Blogger to WordPress. Continue reading “Blogger vs WordPress”

What to make for Valentine’s day?

Looking for an idea for Valentine’s day. Look no further.

What to make for Valentine’s day? A bare perfboard with a Valentine’s chaser (basically a 555-chip, 4017 decade counter and a handful of leds) doesn’t look too impressive. That’s why I made this heart shaped wooden box with a laser cutter. Both printboard and battery fit nicely into the box. Three bolts, nuts and washers to finish the job.

The file for the laser cutter (.svg) can be found here.

And here is a 3d printer file (.stl) of a little dock for the heart.

 

Assembling a Hephestos 2 printer

Is this 3d printer a good choice for a beginner?

Introduction

While making my projects like the Darth Vader chest box 2.0 I use the local fablab a lot, especially the laser cutter and the 3D printer. It was a bit boring to wait for the 3D print to finish (laser cutting is typically much faster) with not much else to do at the fablab. I therefore decided to buy my own 3D printer. I choose for the BQ Hephestos 2, a sturdy Prusa i3 all metal printer that comes in a kit. Continue reading “Assembling a Hephestos 2 printer”

Darth Vader chest box finished

Most impressive. Obi Wan has taught you well.

The main features of the Darth Vader chest box are:

  • enclosure laser cut plywood (6mm)
  • easy control with four push buttons
  • DIY voice changer circuit with Holtek HT8950A
  • LM386 amplifier
  • build-in speaker
  • audio-in (3.5mm)

When I started the Darth Vader chest box early december 2015 I didn’t expect it would take me almost two months. Finally this week I finished it and I’m happy to say that it works great. For a couple of weeks it was almost finished but there always seemed to be some work to be done. A major problem was that I couldn’t get the 3D printed container for the audio-jack right. I tried it several times at my local fablab but it just didn’t fit. Finally I ordered the container from 3D Hubs and it had a perfect fit. Continue reading “Darth Vader chest box finished”

Expanding my electronics workbench with shelves

You can never have enough space

Last week I made a electronics workbench from scaffolding wood and galvanised steel. When working with electronics you need a lot of storage space. Therefore I wanted to make shelves, preferably in the same style as the workbench. I like the workbench but the price of the galvanised clamps was steep. Luckily I found an online supplier that offers the clamps for 1/3! of the price that I paid at my local hardware store. The total price of the shelves was $30 using some scaffolding wood that was left over from the bench.

I sanded the wood thoroughly carefully removing all splinters, drilled two 28mm holes for the steel pipes in each shelf. Next I applied three successive layers of oil to the wood. I cut the steel to the desired length and assembled the clamps. Each shelf is hold in place with 28mm lock rings. I fastened the whole construction to the concrete wall. Below is some imagery of the shelves and the workbench.

The now populated electronic workbench and much needed shelves.
Finished scaffolding wood, galvanised pipes, clamps and locker rings. Time to assemble the shelves.
Top shelf with the clamp and lock ring visible.
Detail of the bottom shelf. With the socket screws it’s very easy to adjust the construction.
Finished shelves fastened to the wall.

 

Homemade desk of scaffolding wood

Introduction

The desk that I used as an electronics workbench is rather small. Since my electronics hobby is expanding, as hobbies tend to do, the small size of the desk became a burden. It was time for a new one. While searching on the internet I found an L-shape desk from reclaimed scaffolding wood on Etsy. The L-shape desk will fit perfectly into the corner saving a lot of room. The desk is really nice but is also very expensive (about $1500). Looking at the image I thought it is not very difficult to make even with simple tools. I was able to build it for $300 with eight planks of scaffolding wood (8″ wide), three planks 2.5″ wide , 6 galvanised pipes one meter length (28mm thick), four T-clamps and four supports clamps. Here are some photo’s of the table and the building process.

Note: I later discovered that the clamps and pipes can be bought online for onethird! of the price that I paid at the hardware store cutting the material cost by half ($150).

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Scaffolding wood sawn and sanded.
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Cutting the pipes with a Dremel DSM-20.
Assembly with a 2" board screw
Assembly with a 2″ board screw
Using a an oil instead of a varnish. Applied with a towel to in three layers to darken and protect the wood.
Using a an oil instead of a varnish. Applied with a towel to in three layers to darken and protect the wood.
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L-shaped table placed in a corner of the room. I added some support to flatten the top of the table. I also flushed the screws with the surface.
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Installing my tools and parts on the table and below.