Integration… It’s not just about that silly ‘S’

Many years ago, I got about a dozen 16×16 bi-color LED display panels that were a part of a broken segment on a marquis. Until now, they’ve been sitting in my spare parts cabinet just waiting for a project to come up. Nothing has and now space has become a premium, so it’s time to do something with them or get rid of them. Since I haven’t used them before and I don’t have a display driver, I don’t know how useful they will be or even if they will work.

When these panels came to me, they were mounted on a frame and had small FPC (flexible printed circuit) ribbon cables connecting each row in series. The backs are printed with two part numbers KLM-163-CAH and KLM-163-CAN which made tracking down a datasheet challenging. I found one on The panels are powered by 5VDC and take 5VDC TTL logic levels (making them 100% compatible with Arduino or any other 5V microcontroller).

In terms of basic operation, you have to select the line, write a serial string to indicate the LEDs to light, then flip an enable bit to lock in that sequence until you get done with the next line. The serial data is timed by an external clock so timing with the serial sequence isn’t important. In fact, I bit-bashed my way through the example code and it worked just fine. The display only shows one line at a time, so you have to be able to scan through the sequence pretty fast. The data sheet has a pretty clear timeline of the sequence of operations, so figuring out the timing shouldn’t hold you up. The only thing that I got hung up on (and still haven’t figured out) is an offset on line addressing, but I’ve worked around it with a 15 line offset.

I also put a bit in the code that allows the Arduino to accept a serial sequence (through the USB port) and it will display that sequence. I tested it using HyperTerminal and it showed the bit-wise ASCII codes for the keys I pressed (so that’s success, right?)

I plan on writing at least one more post about these displays, so look for that in the future.

Here is the Arduino code I used to drive the display:

#define SBaud 9600

#define OE 2 //Out Enable pin
#define Latch 3 //Latch pin
#define CLK 4 //Clock pin
#define GData 5 //Green data pin
#define RData 6 //Red data pin
#define Ad0 8 //Address bit 0 pin
#define Ad1 9 //Address bit 1 pin
#define Ad2 10 //Address bit 2 pin
#define Ad3 11 //Address bit 3 pin
#define Timer 0 //Delay Timer

#define RowMin 0 // Decimal min in row
#define RowMax 15 // Decimal max in row
#define ColMin 0 // Decimal min in col
#define ColMax 15 // Decimal max in col

#define SMax 32 // number of bytes to read from serial

word Display[] = {0×0000, 0x03C0, 0x0FF0, 0x1FB8, 0x3F1C, 0x3F8C, 0x7EC6, 0x7C46, 0x760E, 0x631E, 0x303C, 0x387C, 0x1CF8, 0x0FF0, 0x03C0, 0×0000};
int Di = 0;

int Row = 0;
int Col = 0;

void setup() {
pinMode(OE, OUTPUT);
pinMode(Latch, OUTPUT);
pinMode(CLK, OUTPUT);
pinMode(GData, OUTPUT);
pinMode(RData, OUTPUT);
pinMode(Ad0, OUTPUT);
pinMode(Ad1, OUTPUT);
pinMode(Ad2, OUTPUT);
pinMode(Ad3, OUTPUT);

//Start with all bits low
digitalWrite(OE, LOW);
digitalWrite(Latch, LOW);
digitalWrite(CLK, LOW);
digitalWrite(GData, LOW);
digitalWrite(RData, LOW);
digitalWrite(Ad0, LOW);
digitalWrite(Ad1, LOW);
digitalWrite(Ad2, LOW);
digitalWrite(Ad3, LOW);

//Start the serial monitor
Serial.begin(SBaud, SERIAL_8N1);
Serial.setTimeout(1); //stop checking the port if no data is available after 1 ms


void loop() {

//check the serial buffer for data, if there is some, use it
//otherwise continue putting data on the screen
if (Serial.available() > SMax) {
//when enough bytes are available to fill the screen, load them into the image buffer
for (Di = 0; Di <= SMax ; Di++){
if (Di%2 == 1) {
Display[Di/2] = word(highByte(Display[Di/2]) ,;
else {
Display[Di/2] = word( , lowByte(Display[Di/2]));
for (Di=0;Di<SMax;Di++){
if (Di%2==1){

// initialize enable to be high (disable)
// Step 1. Bring both Latch and Enable High to prepare for new data
digitalWrite(OE, HIGH);
digitalWrite(Latch, HIGH);

for (Row = RowMin; Row <= RowMax; Row++){

// Step 2. With Latch and Enable High, set the row address

// Step 3. Enable goes low to activate the display
digitalWrite(OE, LOW);


// Step 4. The bitwise data is written to red and green
for (Col = ColMin; Col <= ColMax; Col++){
writeBit(bitRead(Display[Row],Col), 0);

// Step 5. After the row is done, bring Enable High and
//Latch Low to set the data for that row
digitalWrite(CLK, LOW);
digitalWrite(OE, HIGH);
digitalWrite(Latch, LOW);
digitalWrite(Latch, HIGH);

void writeBit(boolean RVal, boolean GVal) {
digitalWrite(CLK, LOW);

if (RVal) {digitalWrite(RData, LOW);}
else {digitalWrite(RData, HIGH);}

if (GVal){digitalWrite(GData, LOW);}
else {digitalWrite(GData, HIGH);}

digitalWrite(CLK, HIGH);

void writeAddress(int RowNum) {
if (bitRead(RowNum,0)==1){ digitalWrite(Ad0, HIGH);}
else {digitalWrite(Ad0, LOW);}
if (bitRead(RowNum,1)==1){ digitalWrite(Ad1, HIGH);}
else {digitalWrite(Ad1, LOW);}
if (bitRead(RowNum,2)==1){ digitalWrite(Ad2, HIGH);}
else {digitalWrite(Ad2, LOW);}
if (bitRead(RowNum,3)==1){ digitalWrite(Ad3, HIGH);}
else {digitalWrite(Ad3, LOW);}

That was my project day!

If you liked this project, check out some of my others:

Instant Parade!

The ThrAxis – Our Scratch-Built CNC Mill

Give Aging Technology a Chance

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Featured Artist Nameplates

As engineers, my wife and I are constantly using our left brains, so we find it’s nice to quit analyzing and get creative. I’m building that these nameplates will add some sophistication to our little hallway amateur art gallery.

Between my dad’s and my sister’s photography, my wife’s paintings and drawings, and my wife’s best friend’s paintings, we have a very diverse little art gallery growing in our hallway. We’re very proud of the artists in our family and they deserve to be recognized for their work. I started thinking about this project as just simple aluminum plates with names stamped into them. While that concept would have been good enough to fit the function, the aesthetic just wasn’t what I wanted.

Featured Artist Nameplate

Featured Artist Nameplate

I used layers of material to make the nameplates 3-dimensional and used the textures and shapes of different kinds of materials to give them character. I used plain poplar for the base (closest to the wall), perforated stainless steel for the second layer, and of course the aluminum for the top layer. Thankfully, the aluminum polished up fairly well and makes the letters pop out, so they are pretty easy to read. I used simple washers to put spacing between the plates.

Stamping Jig

Stamping Jig

It took a while to get the lettering just right. At first, I tried stamping free-hand, but the smallest turn of the stamp or the smallest misalignment between letters ruined the whole plate. Ultimately, I made a jig out of spare aluminum plates and some angle shapes. Getting the spacing and alignment just right was the hardest part of the project. I also used hash marks on my workbench to get the spacing down.

That was my project day!

If you liked this project, check out some of my others:

Instant Parade!

Lukewarm Drill Press Bench

Set Your Creativity Adrift

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Lukewarm Drill Press Bench

Space is a premium in small workshops and there are many ways to overcome the limitation space has on tool sizing. One way to fit big tools like my drill press in my garage work space is to make them mobile so they’re available when needed and can be stored when they’re not.


Finished Drill Press Table

Finished Drill Press Table

This project has been in the back of my mind for quite a while. You see, I have a small bench-mounted drill press that is very useful and, for some projects, necessary. The problem with it is that in my garage workshop, I don’t have a bench to mount my bench-mounted drill press to. So, every time I use it, I have to pick it up off the ground and set it up on a small portable bench, then tear it all down again when I’m done. Even if I just built a bench for it, I don’t have any wall-space left, so the bench would have to sit in the middle of the workshop taking up valuable floor space that I will probably need for something else. It’s also to my advantage to design my workspace so it’s reconfigurable since my projects range from small-scale electronics and widgets smaller than a credit card to furniture-sized constructions. What that means for a drill press is that sometimes, I may only need to have the working space of the table (that’s the suspended platform below the spindle and chuck) and other times, I’ll need several feet of space on either side. The key to make all of these things possible without turning my garage into a logistical nightmare is to make the drill press bench mobile.

I’ve made a few workbenches before and the easiest and most economical materials I know are 2x4s and plywood. As long as you have some basic dimensions in mind, 2x4s and plywood make building a bench so easy I feel like it practically builds itself. In fact, this build was made even easier because it’s based on the plans for a drill press bench I had built previously. If you have the skills, I suggest you make a sketch of the final version of anything you build because you never know when you will want to rebuild it or use the design for something else. As for the mobility portion of this design, I knew the bench would have to lock into place when I went to use it. In the planning stages, I decided against using locking casters since there is quite a bit of movement you can get out of them even if they are locked. Instead, I opted to have wheels on one side so I could tilt the bench to wheel it into place, then tilt it upright to set it down. The original plan was to put a steel rod through some of the 2x4s, hold it in with cotter pins and buy some harbor freight wheels and hold them on with washers and more cotter pins. This plan didn’t pan out because to buy the materials for that idea would only be slightly less expensive to build it myself than to buy a dolly on sale. Honestly, buying the dolly feels a little like cheating, but in spite of what you might think while reading my blog, sometimes it’s just better to let someone else do the work.

Table with Dolly Attached

Table with Dolly Attached

One of the big parts of designing this table is that the drill press is top-heavy and so I can’t make the table too narrow otherwise it’s at risk of falling over. To overcome this risk, I performed a tilt analysis as part of my design. Using geometry, you make some educated guesses about where the center of gravity of the table plus drill press is, then make some more educated guesses about how far the table should tilt before it falls over, then make a footprint that matches those two conditions. Because this table is designed to tilt to move, I used a scant 10 degrees as the maximum tilt angle and assumed the CG was pretty high, justifying the 24″ base.

The build process is fairly straightforward. Measure and cut the 2x4s and plywood, then make like the Avengers and assemble. I used a circular saw to make the cuts, but a chop saw would work, too if you have one. One trick when cutting lengths of material down is to cut the pieces in order from longest to shortest. In this way, if you make a mistake, you can cut the mistaken piece into the smaller pieces and still minimize waste. During assembly, I try to predrill as much as is practical. In this case, the 3″ drywall screws work best when you predrill the lumber nearest the head of the screw with an 1/8″ hole. The pilot hole allows the screw to go through at the angle exactly how you want it to and the two boards will squeeze in tight as the screws are tightened to make a solid structure. Rather than constantly swap the 1/8″ drill bit for the phillips screw attachment in my cordless drill, I had my 120V corded drill set up with the screw attachment and the cordless set up with the drill bit. It went way faster that way, but the corded drill was severely overpowered and it made the bit skip in the screw head. In retrospect, I probably should have had those two reversed so the right tool was used for the right job. Primitive Pete strikes again!

I made a lot of missteps on this build. I started with the plan to build the square top and the shelf borders first, then secure them to each other with the legs and finish with the plywood tops. As I built, I changed my mind and decided that it would be best to try to build the whole table from one side to the other starting with two legs and one quarter of the square top and shelf borders. The idea was that when the top and shelf were 3/4 built, the plywood could be put in and clamped in place with the last quarter of the platform. Instead of being the elegant solution I thought it would be, it was a disaster. Finally, I reverted back to the original plan which ended up working much much better.

I finished the table with some gray paint that I randomly chose at the hardware store. I wanted to use a neutral color that wouldn’t be overly dark or light so marks would show. I didn’t go to the store with a plan and decided while there that the middle gray color the store had chosen for their display bases was just right. All the way home from the hardware store, I wondered if I had made the right choice, but the color has worked out pretty well, so far. If I find I don’t like it as time goes on, I can always repaint it. I also used some chrome corner caps to keep from bashing knees because the top of the table is at the perfect knee-bashing height.

I’ve mounted the drill press and I’m letting the table settle into the garage space, but I don’t think it is a huge success. I think I misjudged how large the top of the table needed to be and so it takes up a considerable amount of room. Much more room than I expected. I’m seriously considering cutting it down to be much closer to just the footprint of the drill press.


Since the original posting, I’ve reduced the size of this table from the original 27″ x 27″ to a much more modest 14″ x 19″. At that size, the dolly is just the right width and there’s just enough room underneath for my toolbox. I’ve used it a couple of times so far and I’m really happy with the height and how easy it is to move around.

That's Much Better!

That’s Much Better!

That was my project day!

If you liked this project, check out some of my others:

Wooden Time Machine

A Twist to Build a Dream On

Growing Projects One Dimension at a Time

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Hot Rod Red Robot Controller

I’ve always believed in working harder by working smarter. So when I do a task more than once, I take a minute to consider if I could make life easier for myself by making a tool, gadget, or program like this controller that will keep me moving forward instead of being stuck in the doldrums.

When I’m working with my PicAxe, Arduino, Raspberry Pi, or even just PLCs, I keep finding myself building the same kinds of prototype circuits over and over again. Circuits like switches, buttons, and potentiometers as voltage dividers or as current limiting devices come up all the time. I’m sure if you’re electronically-oriented, you have had the same happen with you. Instead of having these parts clutter up my solderless breadboard, I decided to make a controller that would house the devices that I could simply wire into my prototypes… and do it with style!

Since I’ve been building prototype circuits with these components for years and it’s mostly straight connections it didn’t take any effort at all to make the electrical plan. The real challenge of this project was planning out how the components I wanted would all fit on a single panel. On one extreme, I could make it a big, obnoxious contraption with everything I could possibly ever need, but completely unwieldy or on the other end of the spectrum, something so small and specific that it’s not useful. Aside from the use / aesthetic spectrum, I also have more than enough prototyping components, so one self-imposed limitation was that I didn’t want to go nuts buying all new stuff. That brought the challenge that I’d have to build the project around these two massive industrial joysticks that I have. If space is such a premium, then why two joysticks you ask? “To control robots”, I would answer.  In the end, the limiting factor for the every dimension of the panel was the size of the joysticks. I managed to fit two switches, two potentiometer / rotary selector switch knobs, and five push buttons in the space between.

Enclosure Base Complete with Unused Hinges

Enclosure Base Complete with Unused Hinges

The build started off as a box with feet and a hinged lid which the components would be mounted to. That was going to give me the flexibility to easily open the cover and make changes, if needed. The hurdle with that design is that the lid, being made from very thin aluminum, would need to be reinforced so it didn’t flex every time you touched it. Also, there are the pointy corners to consider. Every iteration of a supported lid that I came up with was either clunky or complicated or both, so I decided that a fixed lid was the way to go and I’d just have to deal with reaching through the controller to make changes. Between the easy-to-manage handy panel siding and the square material used for bracing and the legs, it took very little time to build the enclosed bottom of the controller. The hardest part was visualizing interacting with the controls and planning where to put them and how to plan for the possibility of changes in the future. For this project and any others you might have dealing with sheet metal and drilling holes, I recommend you buy a set of step drills. Not only do they make much larger holes than you can practically make with general purpose drill bits, but they will also debur the hole after they cut it.

Finished in Shiny Red

Finished in Shiny Red

After I had the enclosed base fitted with the aluminum plate, I test-fitted all of the parts to make absolutely sure everything fits and painted the whole thing with red automotive paint. It’s not by best paint job, but it gets the job done. I may repaint the base or the plate with a different color to give it some personality.

Going forward, this will be great for prototyping. If I need a joystick in a permanent build, though, I think I’ll go for the mini joysticks available from Parallax or others instead of using a joystick almost as large as the robots I build.

That was my project day!

If you liked this project, check out some of my others:

Instant Parade!

The ThrAxis – Our Scratch-Built CNC Mill

Give Aging Technology a Chance

Did you like It’s Project Day? You can subscribe to email notifications by clicking ‘Follow’ in the side bar on the right, or leave a comment below.

Set your Creativity Adrift

If you like the beach like I do, here’s a way to literally bring a piece of it home… and not look like a packrat. Also, you can make a nice decorative piece for your mantle, coffee table, or end table.

Like many newly-married couples, my wife and I are working on dressing up our home. We’ve decided that the front room should reflect the lifestyle we admire and enjoy (and secretly wish we had); beach houses. We really enjoyed seeing driftwood sailboats and decided that they were a décor element we wanted to include in our living room. There are innumerable variations of driftwood sailboats all over the internet, interior design magazines, and in high-end beach décor stores. In those stores, they charge as much as $35 each for a large one. Obviously, I’m not going to pay so much for a decorative bauble, so I decided I’d give making some a shot before I shelled out so much cash. I also couldn’t make only one because a single boat would be a show-piece, so every flaw I didn’t cover (and couldn’t because I’m using raw natural materials) would be obvious, but several boats would be a collection and the flaws on one piece aren’t so obvious.

I based my design on the basic and most common features of the sailboats I’ve seen: Driftwood hull, simple mast, and cotton cloth sails. My designs started with some driftwood I had collected from the beach (just waiting for the right project). Rather than make a boat design and then try to make the driftwood fit the design, I figured it would be much easier to make the driftwood look like a boat if I used the features of the wood to imply boat-like features. Allowing the shape of the driftwood guide the design of the sailboats is a very straightforward concept, but if you, my reader, aren’t familiar with planning out projects before just going for it, then this might be an important detail that gets overlooked. Driftwood for the hull will probably be the hardest material to get, but it’s also the cheapest if you live on the coast. Finding some wasn’t so hard for me because I had a small collection I made while beach camping last year. I decided that, for simplicity, the masts would all be the same diameter across the three boats, but the position and angle would distinguish them from each other. I also didn’t want the design to be too complicated, so I gave them all triangle sails with holes reinforced with eyelets and held up by small screw eyes with craft string rigging.

Sanding Facets in the End of the Mast

Sanding Facets in the End of the Mast

The build process was actually pretty straightforward. I started by cutting and preparing all three mast-dowels. I sanded the tip of the mast that you’d see in such a way that it looks roughly faceted with the intention that it would make the wood match the driftwood better. Next, I drilled the holes in the tops of each driftwood hull for the mast and the pilot holes for the screw eyes. The masts were then glued into place with Elmer’s wood glue and after it dried, I used the mast as a handle to help me sand the bottoms of the driftwood flat so they would sit upright on a table. It took a few tries to make them sit upright well enough, but save yourself some time and don’t worry if they don’t sit perfectly, the angle will change when you add the weight of the rigging string, screw eyes, and sail. Putting one screw eye at each end of the boat, on the tip of the mast, and at the base of the mast finishes the boat.

Masts and Screw Eyes In Driftwood

Masts and Screw Eyes In Driftwood

I made the mistake of trying to trace the outline of the sails directly to the cloth by laying the boat on top of the cloth and marking the corners. If you try something similar, I recommend you trace the shape of the boat on a scrap of paper, make the sail shape there, and use the paper as a stencil for the cloth. Also, the lack of stitching in the sail means that as soon as you start cutting the cloth, you’ll need to be very wary of unravelling, so try to handle the cloth as little as possible. Immediately after cutting the cloth, I set it down on some scrap paper and laid a small bead of fabric glue around their perimeters to keep the edges from fraying. After the fabric glue dried, I cut slits in the cloth, cutting between threads to (you guessed it) keep the unravelling to a minimum. Seat the eyelets and you’re done. I had to tie and untie the rigging without the sails many, many times before I could figure out what looked right, so don’t give up until you get it just right. After you get the whole thing assembled, don’t forget to sand the bottom a little more so the boats sit upright. Honestly, you can’t forget because the boats will probably fall over.

Making Sails

Making Sails

I had a lot of ideas about how to assemble the hull, rigging, and sails, so rather than try to figure out which version was the very best and make all three identical and boring, I made each one unique. For example, one boat has no sails. On another, the sail is secured to the mast by the screw eyes instead of by the rigging. The third has the rigging sandwiched between the sail and mast unlike it’s counterpart which has the rigging in front. Also, on one I decided to set the mast at an angle in the assembly stage, just to make it different.

None of These Boats is Quite Like the Other

None of These Boats is Quite Like the Other

So, in summary, you get some driftwood, pop a hole in it, then glue a stick in the hole, drape some cloth on it, and you’re done! The fun of this project is figuring out how YOU want to make it.

That was my project day, how was yours?

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Wooden Time Machine

I don’t know how to start this introduction, but the punchline is: If you don’t want to go broke buying picture frames made from reclaimed wood that is probably just chemically treated  new lumber, then spend between $10 and $20 and a couple hours making your own. I did and this is how I did it.

Very recently, I found that I needed a frame for an oddly sized poster. The image on the poster is an 1852 map of San Francisco. Since I’m not a fan of highly ornate antique styles (which I guess might have been appropriate for a wall-hanging object from the 1850′s), a rustic-styled frame was the clear choice since it would make the poster and frame seem like a “found” object. I looked into buying one, but the closest thing I could find to what I imagined were picture frames that looked like they were made from reclaimed wood, but they were so prohibitively expensive they would have cost several times as much as the poster. Since I’ve made a thing or two out of lumber, I knew I could make a frame. The trouble was, how would I get the lumber to look like I wanted? Thanks to the infinitely available information on the internet, I was able to easily find more than a dozen websites describing the process for “distressed” wood finishes and quite a few for “reclaimed wood” finishes. If you’re planning on doing a similar project, you should spend some time looking at the different ways that other people have done similar processes.

The website I used for reference described how to give boards an artificially aged look using three steps: paint the wood, roughly sand a majority of the paint away, then stain the exposed wood to make it look weathered. With this in mind, I bought a sample jar of paint in a light blue color that I chose to be close to the colors in the room. The sample jars of paint only came in flat which is fine because it doesn’t look shiny and new, but the paint will take the stain a little. I also chose a darker stain because I figured it would give the best contrast between the aged and worn and the ‘old’ paint. The stain I used is Minwax’s Jacobean which ended up being a little darker than I was expecting. Your mileage may vary, but I needed a little less than 16 feet of 1 x 2 lumber for my frame design. I chose a material at Home Depot called Trim board primarily because it’s not particularly expensive (20ft cost me ~$7) and also because a couple of the sides are pretty roughly cut. It’s so rough in fact, you’re likely to get a splinter just from looking at it. The roughness works to my advantage over a smoothly cut board because the paint will settle in the low points of the wood, making it easier to leave behind paint remnants when I sand in the second step. After the finish is complete, I’ll need nails and wood glue to hold the whole thing together. One trick I learned the hard way was if you’re going to use wood glue to hold parts together, do the surface finish first, assembly second. The glue chokes the wood grain which prevents the stain from taking hold and the finish will look like salt water dried on the glue joint.

Very Rough Lumber Sanded much smoother
Rough Lumber from the Hardware Store Much more suitable after some sanding

Even with a simple project like this, its best to work from a drawing or a sketch so you don’t get confused and cut the wrong board, so the very first thing I did before I put saw to wood was spend a little time making a post-it sketch. After cutting the boards to length, I spent some more time preparing the wood for the next steps. The little details that go into a project are surprisingly important to giving the finished product a believable appearance. For example, sharp edges and splinters make the boards look new, but breaking the edges and removing the splinters with rough grit sandpaper automatically makes them look older and more worn. As an added bonus, the splinters would have clogged my paint brush if they had stayed, so they must go. I know it must seem like a contradiction that I bought rough wood only to sand it, but I didn’t sand it completely smooth and if you saw how rough this wood is, you would understand completely. Even though I had more than enough paint 100% of the lumber many times over, I didn’t want to waste it (or my time), so I carefully picked which faces of the wood would be showing once the frame was assembled so I knew where the paint needed to go.


Full Paint Coverage Not Required

The next step is really easy: slop some paint on the boards and let them dry overnight. The next day, after the paint has completely dried, I used my orbital sander with fine grit sandpaper (the medium and coarse just take the paint away too fast) to work the paint and wood down until there were just remnants in the grain. If you take on a similar project, be careful to sand safely, but don’t be too careful in sanding uniformly because sloppiness will look like age and wear. I made sure to wipe, brush, and blow away the dust before I began staining to keep from cross-contaminating the stain in the can, but also I wanted the frame to look old, not dirty. There’s also one trick I remembered after I was done that I wish I had used here. Instead of just jumping straight into staining this very dry wood which soaks the stain up like a sponge: Spray some water over the boards and let it soak in, then wipe them off before getting started. The water will hinder the stain from setting in too quickly, making it easier to make the grain pop out like aged wood does without turning it all even and dark. I applied the stain, then immediately wiped it off. Because I didn’t do my trick with the water, it ended up a lot darker than I wanted, but the look grew on me. I found that the flat paint I used seemed to soak up some of the stain, but it makes even the paint look a little older, so maybe that’s a good thing, but it’s something to consider when picking your paint color. I let the stain dry out some before I started gluing parts together.

Paint mostly sanded

Painted and Sanded. Ready for Stain.

When I was ready to assemble, it went together in minutes. Just glue, and nail. Glue and nail. I used a sturdy, level table top to make sure the frame was flush as I assembled and a pneumatic brad nailer to fasten the pieces together. When the glue had dried, I attached a couple rings to the back to hang it on the wall and mounted the poster to the front with upholstery tacks that looked like hammered brass. The tacks fit the rustic look I was going for.  Then the most important step: hang and enjoy!

Picture Frame

Finished ‘Reclaimed Wood’ Picture Frame

That was my project day, how was yours?

Did you like It’s Project Day? You can subscribe to email notifications by clicking ‘Follow’ in the side bar on the right, or leave a comment below.

Build a Virtual Anything with Cardboard

What do you get when you combine two parts velcro, two parts magnet, two parts glass, and fold them into a little bit of cardboard? According to Google, that’s how you get a glimpse of the future… and the view is GREAT!

In June of 2014 at the Google I/O event, a team of three developers presented a simple DIY device that could transform your smartphone into a virtual reality headset which they simply called Cardboard. The presentation they gave (shown in the video below) demonstrates them using the cardboard hardware with a software development kit to build an app. The reality is, it takes a lot more than leftover shipping material to make your own Cardboard headset. The hardest part to source is the two biconvex lenses you’ll need to reduce eye strain. With the event long over and these lenses in high demand, you can find many versions of Cardboard as kits and they save you just enough headache to make it worth the extra cost. I got mine from DODOcase. The design is basically the same with perhaps a little less cardboard (the material) involved.

Google I/O 2014 – Cardboard: VR for Android

So, how did Google take a simple building material to make such an impressive device? I thought I’d never ask… The basic technology at work here is stereoscopic photography which is an optical trick that’s been around since before penny arcades. I remember being mesmerized by the picturesque landscapes of my View Master, which did basically the same thing. What happens is each eye is presented with one of a pair of pictures which are taken at roughly the same distance apart as your eyes. When you do that, your brain stitches the images together just like you were looking at it in person and PRESTO! you’re overlooking Niagara Falls from the comfort of your living room. Google then took that and added the accelerometer and gyro in your smartphone to allow you to move around within these virtual, stereoscopic pictures making them more immersive. They also use a magnetic field interacting with the hall effect sensor in the phone to give the ability to interact with the virtual space.


The DODOcase Cardboard VR Toolkit Assembled

There are lots of technologies that have been developed in the pursuit of letting people see in three dimensions. The one people my age can remember from childhood are the red / blue tinted 3D glasses. These work by taking one image that you can focus on and splitting the color information between each eye. A similar technique is used in 3D films where polarization is used to split an image instead of color. Active Shutter 3D glasses also split a single image into information for each eye by rapidly alternating blacking out light from each eye at the same rate that the image on the screen changes. The Cardboard technique is a little older and doesn’t bother trying to overlay one image on another. On the plus side, you can get really good 3D imaging results without much technology to figure out (which means lower cost, etc). On the negative side, however, this technique can lead to eye strain because not every pair of eyes is the same distance apart. To illustrate, lets say that your eyes are 1cm closer together than the average pair of eyes that Cardboard was designed for. Then lets say that the simulated image is a ball floating in air straight ahead of you, so the simulated image for an average person would have the image of the object just slightly off center toward your nose so that both eyes settle on the image and your line of sight is where the object would be if it were actually there. To your slightly narrow-set eyes, the image would appear closer to right in front of your eyes, making the object seem further away and distorts the 3D effect. Don’t misunderstand, eye strain of this sort plagues every 3D viewing technique, but it can be more pronounced when the actual image is closer to your face.


The Business-End of Cardboard

The head-tracking feature is a pretty exciting one, too. It works on the principle that in any cartesian coordinate system, movement can be described by 3 dimensions of translation and 3 dimensions of rotation. I’m guessing that the apps on the phone will not account for translation. I came to this conclusion from experience and also by imagining idiots like me holding the VR headset up to their faces while tripping over furniture. Using the information from the accelerometer to tell the phone which direction is down and the angular rate from the gyro (that’s how fast it’s turning), the phone can calculate about which direction you’re facing. There are apps that do this very well with very sophisticated integration and error correction algorithms and there are others that don’t do this well at all. One app that comes to mind will track your head if you move, but once you stop moving, the image slowly drifts back to dead center again. It’s possible that this was done deliberately to keep the viewer’s eyes up front, but I can only guess.

Obviously, I think this technology and implementation are awesome and I’d like to see more happen with it. Some things in particular are more stereoscopic videos on youtube and for NASA to convert it’s library of stereoscopic images from Mars to work on Cardboard. Perhaps the technology could even be extended to augmented reality.

That was my project day, how was yours?

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Salvage – It’s Not Just for Sinking Boats

What do you do when your beloved printer, scanner, blender, or remote controlled car breaks? I’m glad you asked because this weeks’ post is about salvage. I’m going to use my experience to help you quickly sift through the junk and help you find the good stuff.


( sal-vij )  – To rescue or save from fire, shipwreck, danger, etc.

In this sense of the word, I mean “to rescue the engineering from broken devices.” I know that seems a simple, but confusing turn-of-phrase, but I’ll break it down into two parts. First, I disassemble broken devices or more broadly, devices that people don’t want any more, so I’m not contributing to waste and I’m squeezing just a little more utility out of it than it would normally have. Second, I’m taking away from the device the engineering knowledge that I can glean from the arrangement of parts and the parts themselves to use in my own projects. From when I was a kid, I thought taking things apart was kind of a puzzle and still do. Since I’ve earned my degrees in engineering, I also look at each product I disassemble as a lesson in ‘continuing education’.

wpid-img_20140724_190319.jpgAmazing Little Peristaltic Pump Salvaged from an Inkjet Printer

You wouldn’t think about it just by looking, but a lot of engineering goes into the devices we use on a daily basis. Take a ‘simple’ motor for example, its an assembly of no fewer than 6 different materials brought together using additive (casting), subtractive (punching, machining, and polishing), and forming (sheet metal rolling, bending, and wire winding) methods which takes into account electricity, magnetism, thermodynamics, fluid dynamics, and mechanics. So why did the engineers that brought this product together select this motor? What are its special properties? Is it fast? Lots of torque? High voltage (low current)? What about the arrangement of the components? What decisions did the designers make to save money? What cleverness went into making the movement? What about specialty materials like the nichrome wire in toasters? I ask these questions almost reflexively when I take a look ‘under the hood’.

wpid-img_20140723_062032.jpgPrinter / Scanner Combo Destined for the Trash

To help illustrate the process I use to salvage, I’ll refer to a tear-down I did recently of a HP combination inkjet printer and scanner that had stopped printing, given to me by my friend Farzan.

Before I start taking a product apart, even before I bring it home, I try to figure out what parts I’m going in for. Lets face it, with places like Best Buy taking old electronics to recycle the e-waste, it’s far better for the environment to take it in than take it apart. (Maybe a peek inside the case before you take it in wouldn’t hurt) At the same time, also learn to recognize when something has no redeeming value and send it on its way. With the inkjet printer, I was sure from my experience stripping down other flatbed scanners that I’d find at least one stepper motor inside, a linear guide, and maybe a photogate or two. Knowing what you expect to find will inform how aggressively you can take the product apart. What I actually got out of the inkjet printer leads me to salvaging lesson number 1: When you salvage for parts, you don’t always get what you were expecting.

wpid-img_20140723_063139.jpg wpid-img_20140724_181056.jpg
DC Motor with Integrated Encoder
Strange USB Adapter and Wifi Card

I was really just blown away by how many interesting, useful things I was able to get out of this printer/scanner: 3 motors (1 with a linear drive belt and another with a built-in encoder), a fully enclosed dual-voltage 12V & 32V power supply (low current), screen with faceplate and bevel that I might be able to repurpose, peristaltic pump with bleed valve and drive gearing, wifi adapter card for experimentation (maybe), springs, rollers, USB cable adpater, button-cell battery holder, several photo gates, a pane of glass, and an SD card adapter. I already have two projects in mind using some of these components.

Always exercise caution when taking an unknown device apart. Since you didn’t design it, you have no way to know what’s in it. The watch-outs I’ve seen are: springs that are stretched or compressed, so they go flying when they slip, unknown lubricants that get everywhere, glass and other pointy / sharp things, and the occasional glass tube filled with a gas. Especially when taking apart flatbed scanners, take care with the lightbulb which I think has mercury in it, but is only marked with the “Do not throw away” symbol. As a mimimum, I recommend safety glasses, but gloves and a well-ventilated area might also be a good idea. So, salvaging lesson number 2: Safety first… even though it’s mentioned second.

wpid-img_20140724_180635.jpgAlways Check Under the Stickers for Those Last Few Screws

Disassembly seems pretty straightforward, but a lot of the ease I have comes from experience. Over the dozens of products I’ve disassembled, I’ve dealt with glues, screws, tabs, catches, springpins, retaining rings, and press-fits, so I know how to recognize how a thing is held together. If you want the product to go back together, start your disassembly process with some pictures and continue taking them throughout. Next, if you’re salvaging for parts, I recommend only taking one part off at a time, when you do that, you get a better understanding of how the parts went together. Start by removing the screws because they are always obvious, but look before you pull pieces apart. A lot of the times, screws are used with tabs or slots or other things that make it easy for the assembly line worker (or robot) to slap parts together, but not easier for you to take apart. On the printer, for example, there were some screws hidden under stickers and some removable components.

The first question I ask myself when I get a device open is “How does this thing work?” Seeing how the components are arranged and how they work together will help you understand the general operation of the device. This will help you figure out which parts you want to keep, find the parts you want, and help you understand the decisions that went into the design.

During this ‘inspection phase’ is where the whole thing becomes a fun puzzle for me. Did the designer make the same arrangement choices I would have? Did they choose the same kinds of parts I would have chosen? Why is that part black and the others white? Is there something special about that connector or this wire or the thickness of the plastic? In general, recognizing differences and figuring out why it’s different is the name of the game. I found a lot of interesting things inside the HP printer. It had a peristaltic pump I wasn’t expecting, included no stepper motors (I was shocked), had a fully-enclosed DC power supply inside the printer case (like Russian nesting dolls), and had a USB jumper that went from a mini B USB port on the board to the standard B port on the case. All of these things were very surprising. I was also in awe of the sophisticated mechanisms used to drive the printing process: I found that through a set of clutches and sliders, the two motors in the printer were able to control two discrete roller movements to draw up the one sheet of paper and keep it moving smoothly past the print head while in a completely different mode, drive the peristaltic pump to (I assume) clean the print heads when they are in the home position. Just remarkable! That makes lesson number 3: If all you get out of a disassembly is the knowledge of how things are put together, then you win.

wpid-img_20140723_062901.jpgNatural Environment of DC Motors

Once you’ve convinced yourself that a part is useful, make sure to take a picture of it in its ‘natural environment’ before diving in. This reference will be a huge help later when you try to build with it. Also, consider what components are upstream and downstream of it. I pulled several motors out of the printer and with those, I had to consider if there was a motor controller built into the circuit board for me to use or if the mechanical linkage on the shaft was useful. Finally, after you pull the component out, make sure you don’t have to save the mounting hardware. I’ve spent many, many hours trying to find the right screw to fit the thread pattern and length on the end-cap of many DC motors, so take some advice and save the mounting hardware. Lesson 4: Save the screws.

After you’ve learned all you need to learn and taken all there is to take, what happens to the left-overs? Depending on what was removed and how much is left, there are lots of options. Generally speaking, I want to consider the environment as much as possible, so my hierarchy for disposal is: reuse, recycle, and then toss if you have to. In the case of computers and peripherals like this printer, if you only take one or two things like a motor or something, you can still button it all back up and turn it in at places like Best Buy and they’ll recycle the e-waste. If all you have are a few body panels, it would be okay to recycle them or throw them out if necessary (that’s what would happen to them if they went to Best Buy anyway). Take care not to throw out anything hazardous like that mercury lamp I mentioned earlier or batteries, etc. For those, check with your waste management company to find out how to dispose of those properly.

That was my project day, how was yours?

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A Twist to Build a Dream On

Some projects, like this deburring/countersinking tool sit on the back-burner for a long time. Dusting them off to finish the job feels like sharing a meal with an old friend. This deburring tool is a handy way I came up with to reduce the amount of time I spend switching between drill bits and countersinking tools to make clean holes in my metal projects.

As many handymen, handywomen, and fabricators know, deburring drilled holes makes them look smooth and professional quality. One way to get a good deburr on a hole is to use a countersinking bit in your drill to just graze the lip of the hole. The problem is that it’s a pain to swap out the drill bit for the countersinking tool. However, there is some relief from the tools already available. There are general deburring tools, speed deburring tools, or manual-style deburring tools shown below. But why buy a tool when you can make one that’s better?

Outside ImageOutside ImageOutside Image

General Deburring Tool, Speed Deburring Tool, and Manual Tool

 This project started with a Yankee push drill. Basically, it’s a manually powered drill that turns the tip as you push down on the handle. The downward force is converted into twist by a mechanism with a steep-angled screw at its core. The chuck is designed to hold the small drill bits that come with the tool. Obviously, the small diameter tools won’t deburr anything very well, so I decided to swap it out for something more useful. I found this countersinking bit and quick-change chuck at Harbor Freight that would work out nicely.

IMG_2556Quick-Change Chuck found at Harbor Freight

IMG_2566Hand Sketch of the Internal Mechanism of a Yankee Drill

Before I disassembled the drill, I had to figure out how it worked so I wouldn’t compromise any critical features of the drill when I modified it.  I made a sketch of what I found, shown above. The modification was easily done by drilling out the rivet holding the chuck in place, then using a lot of leverage to remove the press-fit chuck. (this drill was very well-built).


Drill Press, Chuck, File for Roughing, Sand Paper for Finishing

The internal diameter of the yankee drill was 0.34″, but the Harbor Freight chuck was 0.43″, so I had to turn it down some. I reduced the diameter of the quick-change chuck using my drill-press and a file. The slowest my drill press can go is about 550rpm which was fortunately slow enough to keep the file and chuck from overheating. I used a spring-pin to fix the chuck to the yankee drill and voilà! a new tool is born!

Finished Yankee Deburring Tool

That was my project day, how was yours?

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Thinking Outside the Box Inside a Box

Sometimes the thing you need doesn’t exist in the world. However, you don’t have to use off-the-shelf things only in the way they were intended.  Don’t be afraid to turn them upside down, inside out, or just take it apart to see what else you can use from it. 

Clamshell box half openCryptex Box Half Open

Before we dive too deeply into this project, let me tell you a little bit about me. I find boxes fascinating. I suppose you could say I’m actually fascinated with treasure and the prospect that a box might hold treasure makes it mysterious and alluring and almost magical. And like Schrödinger’s cat, you don’t know what’s going on inside until you open the box and take a look. This is one of the reasons I love the cryptex from Dan Brown’s mystery novel The Da Vinci Code. In the book, the cryptex is a puzzle box, shaped like a cylinder that contains a scroll with a secret code. (so mysterious!) The movie adaptation of the Da Vinci Code was released to video in 2006 and with it was also released the special edition giftset which included a miniature, working cryptex replica. I got one of these, but was uncertain what to do with it once I had it. Unfortunately it just rolls right off of any table you put it on.

The idea for this project was to build a box that I could use to hold the cryptex to keep it clean, but the box also needed to have a shallow bottom so I could open it to display the cryptex when I wanted it out. Every box I looked at had the opposite; a deep bottom and a shallow top. The wooden project boxes from my local craft stores were the perfect size, but I wasn’t satisfied with having the cryptex out of the box for display. Instead, I chose to flip the box upside-down to use the lid as a cradle for display and split the (former) bottom in half to make two clamshell doors.

Project Box closedProject Box Open

Example of Craft Store Project Box

The conversion was really easy, but here are a few tips: on the second door, I had to install new hinges to match the existing ones and that meant cutting notches so they could be recessed. Make sure to cut the notches to the right depth! I used a box saw with a guide to cut the bottom of the box in half. This kept my cut straight and parallel to the sides of the box. Also, stain doesn’t work out with these premade boxes because the glue they use to hold the sides together creeps into the grain of the wood, so it won’t take stain. To finish the build, I glued small, cylindrical neodymium magnets in the walls of the two doors. This makes them snap together and hold fast without a visible catch.

Clamshell Box Fully OpenClamshell Cryptex Box Fully Opened

I thought that the painted look was not quite fitting with the brass and white look of the cryptex. Instead of that solution, I tried something new; I tried to stick paper to the walls of the box. There are a ton of textured papers in your local craft store in the scrapbooking section. I chose a red velvet material for the interior and rough gold for the exterior. the rough gold hides the creases and seams in the paper and the velvet gives the air of sophisticated opulence.

Gold PaperRed Velvet

Example of Gold Outer Paper and Red Velvet Interior Paper

To get the paper to fit perfectly, especially on the interior, I had to draw stencils of the shapes I wanted to cut from the scrapbooking paper with a much cheaper, easier to work with material. I used printer paper to make mock-ups of the shapes. I cut them out, then folded them to test fit the shape into the box. The trick here is to hide the edges of the paper in the creases in the corners. To do that, I made small flaps where two parts of the stencil would meet. The flaps had 45 degree corners to avoid wrinkling the paper in the corner. When I assembled the stencil in the box, I would tuck the flaps under the mating part and make the edge of the mating part lie perfectly inside the corner. This does two things: First, the flap completely covers the inside corner with the same uniform color as the rest of the paper material. Second, the edge of the mating part lies parallel with the inside corner and within it, so a casual observer will only see the crease of the inside corner and not the joining of two parts, making it appear seamless.

Stencil PatternExample of an Inside Stencil

There are other ways you can customize something from the shelf and make it into something that’s exactly what you need. These craft store project boxes are also really handy. I’ve used two or three of them in projects over the years and they really hold up in the workshop.

That was my project day, how was yours?

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