DIY Lego Cabinet

Making a woorden Lego cabinet for all this minifigs is easy and cheap. You do need a laser cutter for this project.

Introduction

My sons have large Lego minifig collections but most of it is lying in a large box. The older son wanted a cabinet so he could display (part of) his collection better. These cabinets can be pricy as I found out so I decided to make one myself. I’ve done some laser cut projects recently, such as the Darth Vader Chest Box and the Valentine’s Heart, so I decided to use the same technique for the cabinet. Continue reading “DIY Lego Cabinet”

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.

 

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.

Homemade Darth Vader Voice Changer 2.0 (work in progress)

Introduction

The last couple of weeks I worked on a homemade voice modulator that is easy and cheap to built. First I’d like to mimic the Darth Vader Voice Changer, but with the press of a button it can be changed to robot or helium kind of voice effects. Last week I’ve steadily continued my work. The project has two main parts, the electronics and the case.

Electronic circuit

For the project I choose the HT8950A voice modulator from Holtek as the heart of the circuit. It is cheap, versatile and easy to work with. I previously had the voice modulator working. I only had to amplify the signal which seemed simple enough. Well, that turned out to be a bit more troublesome than expected. After connecting the LM386 to the circuit and powering it up an annoying hiss was introduced. After some experimenting I figured that the breadboard was to blame and decided to copy the circuit to another breadboard. Although on the new breadboard the hiss appeared somewhat reduced but it was still at an unacceptable level. Even when I removed the input signal from the LM386 the hiss continued. I connected the HT8950A with a audio-jack to an external amp. I wanted to make sure that the hiss was coming from the LM386. With the external amp the hiss was gone. The fact that I had hiss without an input signal indicated that the supplied voltage wasn’t clean.  To clean it up I placed a small capacitor (10nF) from pin 6 (V+) to ground and voila the hiss was gone (see schematics below). It took me some time but I’m almost ready to finish this circuit and solder it to perfboard.

Two (almost identical circuits) with the Holtek HT8950A voice modulator and the LM386 amplifier. Both circuits gave a hiss which was unacceptable. Eventually a simple 10uF capacitor from pin 6 to ground did the trick for me. 
Schematics of the Darth Vader voice changer. I was able to eliminate all the hiss and noise from the LM386.

Printing the case.

I decided previously to make a T-slot plywood case for the Voice Changer but I’m not satisfied with the result. First I made a beginners mistake with the tab width. It was chosen poorly resulting in fragile edges of the case. Also I discovered that a T-slot case is not the best choice for this project. The case needs to be sturdy and the T-slot isn’t. I’m afraid it will fall apart when in use. Therefore I’ll made a regular finger joint that will be glued together. This new case was much better. Gone are the fragile edges and I’m confident that glued together it will be very sturdy.

Laser cut case made out of plywood. I first used a T-slot type of case but made a beginners mistake with the tab width and positioning. As a consequence the edges become very fragile. The front of the case has engravings for the positioning of large controls of the voice changer. These controls on the front will we dummies just to mimic the look of a Darth Vader voice changer. The actual controls will be on the side of the box.
Laser cut case with regular finger joint. This attempt is much better.

Darth Vader voice changer 2.0: designing the case

The first voice changer that I made had a handmade 1/2″ thick plywood case. Making it was very time-consuming and it’s a bit heavy. I felt I could do better. This year I got interested in laser cutting but until now I only read about it. The laser cutter isn’t as widespread as the 3D-printer. The laser optics combined with the CNC bring a whole range of possibilities when compared to creating by hand. First of all you can design with a computer and then send your file to the laser cutter greatly increasing the precision of the case. Second I can make casings that I never thought were feasible, e.g. it is possible to curve the wood by cutting in certain patterns, make complex wood joints normally the territory of professional carpenters or create detailed engravings in just minutes, just to name a few.

In the area where I live there is a FabLab that provides me the possibility to use their laser cutters for a modest fee. I’ve already been there to test the equipment.
To create a case I started with an online tool called Makercase. It’s an easy to use tool that, once you’ve entered the parameters on length, width, thickness etc, provides you with an svg-file. The svg-file can be opened and changed in Inkscape, a free vector drawing program. Adobe Illustrator and Corel Draw are fine too but they are expensive and proprietary programs. Inkscape has a learning curve so I have spend the better part of the week to get acquainted with the program. I nevertheless made good progress and hopefully I’ll be able to have the case ready this week.

Image of the by Makecase generated svg-file. I choose the T-slot design and a thickness 1/4″. This is half the thickness that I used for the earlier version of the Darth Vader voice changer.

Plywood housing for the homemade surveillance camera

In the last two weeks I have built a Raspberry Pi surveillance camera. For the time being I used a crude housing made out of MDF. This was ok for testing purposes but now I wanted something more permanent. Something that I could attach to my window frame and that is able to pan and tilt to get the best angle at my backyard. I could buy of camera housing such as the ModMyPi Nwazet Pi Camera or buy a dummy camera and build the surveillance camera in it. However building it myself would be more fun. I decided on a housing made out of plywood since it is cheap, strong and durable.

The Raspberry Pi surveillance camera keeping an eye on my backyard.

The housing is rectangular box that nevertheless looks like a camera due to the round placeholder of the camera. I used 1/2 inch thick plywood for the body of the housing and 1/4 inch thick plywood for the lid and bottom plate. The camera module is placed between two pieces of plywood, that keep it in place. The two pieces are tight together with two machine screws. I used spacers to prevent the module from being squeezed when tightening the machine screws.

Housing of the surveillance camera
The front of the housing lifted showing the Raspbery Pi B mounted on the 1/4 inch plywood bottom.  
The camera module is easily removed from the front.

I left an opening in the camera housing to have easy access to the micro-USB connector and the SD-card.
the Raspberry Pi camera module between two pieces of 1/4 inch plywood kept together with two machine screws.

The camera housing is connected to a plywood frame that enables me to pan and tilt it. The frame is also made out of 1/2 inch thick plywood. The three pieces are glued together and two 1/4 inch machine screws (one on the top of the housing and one on the bottom) connect the frame with the housing. Two wing nuts are used to tighten the camera enabling the camera to pan. The frame is connected to the wall with cylindrical piece of wood (from a broom stick). Two pieces of plywood at the end of this pieces of wood enable the camera to tilt (see image below).

The finished surveillance camera. The mount will be fitted to our window frame. The camera can be panned and tilted to get the best view of my backyard.

With the housing and mount complete my Raspberry Pi surveillance camera is finished. Motion has been very stable on the Pi. I haven’t had a crash or malfunction in three weeks. And thanks to crontab the camera doesn’t need a lot of maintenance. Is there something left to be desired? Yes. The camera is not usable at night (I need the NoIr camera and IR lights for that) and I have false positives e.g. when it rains (the raindrops on the window are causing this) other than that I’m pleased with the result.

Homemade camera dolly

Finished camera dolly made out of Makeblock and plywood. The plywood is painted black with a regular (alkyd) spray paint.

I make a lot of video’s of our projects so I figured a camera dolly would be a nice addition. I could buy one of course but making one is a lot more fun. About a year ago I bought a Makeblock starter robot kit. The supplier that I bought it from was offering it with a nice discount at the time. The purpose of Makeblock is prototyping but I never used it, until now. Makeblock offers a versatile, sturdy and extensible platform for the camera that seemed very suitable for this project. Even better an Arduino Leonardo clone is included so programming it is not too difficult.

Makeblock claims they have an open source hardware and software platform. Makeblock uses an Arduino clone, called Baseshield, and Arduino is truly open source software platform. The Baseshield uses the RJ25 a 6 pin connector (known for their use in telephone lines) to interface with their sensors. Although this RJ25 is easy to use it is not so easy to connect a generic electronic component to it. This can be avoided by just replacing the  Baseshield with a regular Arduino (EDIT: something I haven’t done in this project). Furthermore Makeblock provides free downloadable CAD drawings of their mechanical parts such as the beams and gears.

I found an example of a Makeblock camera dolly in the internet but unfortunately no documentation was provided. I therfore had to improvise using the Makeblock components that I had. My Makeblock dolly also has four wheels and only a couple of beams are needed. It is very sturdy. It uses two 6V motors that came with the starter set. Each engine has a simple transmission to a wheel via a belt and a couple of gears. The combination of the gears reduces the speed of the motor.

I needed a solution to attach the camera to the Makeblock beams. I decided to make a plywood frame for the camera since I have a lot of plywood lying around. Plywood is cheap but strong enough for this application. With this plywood frame the camera is able to tilt up and down and rotate. With the bolt and nuts I can fix the camera in a desired position.

The plywood frame that serves as a mount for my Xacti camera. The frame is made out of 1/2″ thick plywood cut in strips of 1-1/4″ width. The frame is assembled with 1/4″ bolds and nuts.

The camera mounted on the frame. 

I had to place the camera a bit outside the frame to be able to open the display.

I could have used any other material to make a camera dolly than Makeblock but that would probably have taken considerably more time. On the other hand using wood or plastic is much cheaper. The aluminium mechanical parts are fairly expensive. Some Makeblock parts can easily be replaced by cheaper alternatives. For instance all screw are 4 mm screws which can be bought at the local hardware store. Same goes for shafts and nuts.

The dolly in action with the still unpainted frame.

All in all I’m happy with the result although the dolly still needs some work. First the dolly has a slight tendency to move to the left. I exchanged motors, gears and wheels from left to right but that didn’t made a difference. Also the dolly has no suspension at all which can lead to unstable video’s.

I added a YouTube video below to demonstrate the camera dolly.

Shoe rack finished

Over this weekend I finished the shoe rack for my wive. I decided to use a transparant high gloss varnish with excellent protection against scratches. This varnish “Rambo Jachtlak” is even suitable for boats so I figured it’s can withstand my wives shoe’s.  The price tag of the varnish is hefty but I figured that the rack deserved it. I applied it in two layers with a large rectangular brush. The varnish needs to dry 24 hours after each layer. Once dry my wive immediately filled the rack with shoes and is very pleased with the result. All in all a nice project though not without some mistakes. But as the proverb goes: by ignorance we mistake and by mistakes we learn.
More information on this project can be found on the links below:
http://homehack.nl/?p=29
http://homehack.nl/?p=24

My wive immediately filled the rack with shoes.
Two layers of lacquers were used for a satisfactory finish.

A closer look at the shoe rack. The strips prevent the shoes from sliding.