House of Hacks

Thursday, December 18, 2014

How to quiet a shop vac


In this episode of House of Hacks, Harley shows how he changed a normal shop vac into a central vac system for the shop.

Associate Links

Measuring the efficiency of a centralized shop vac system

Alternate DIY blast gate videos

Background video about the design evolution of the switch

For a written transcript, go to How to quiet a shop vac

Music and sound effects under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at


[Vacuum getting stuck between equipment]

[Vacuum tipping over]

[Loud vacuum]

In this episode of the House of Hacks I'm going to show how I made my shop vac easier to use.


Hi makers, builders and do-it-yourselfers. Harley here.

In general I'm pretty bad at house cleaning. I tend to put off vacuuming and straightening up until it's unbearable. Around the workshop, this is exacerbated by the inconvenience of the shop vac. It has a tendency to tip over on its own cord. It's big and awkward in a cramped space. And it's uncomfortably loud.

I wanted a change based on some requirements: 1) minimal daily setup: it should basically always be ready to use and not take much to clean-up at the end of the day; 2) be convenient when using: I don't want to drag it all over the shop from one tool to another; 3) quiet: I want it to be really, really quiet; 4) inexpensive: I didn't want to spend a lot of money.

So to solve all these issues, I made it into a central vac system. At some point I'd like to get a real dust collection system, but right now that's outside both my money and space budgets.

Today I'll show: the box I built for the vacuum, the way I plumbed it in to the shop and how I turn it on and off. In a future episode I plan to show before and after measurements of both noise and vacuum efficiency and finally some future improvements I'd like to do.

Since noise was a big issue for me, I built this box to hold the vacuum and muffle its whine. In the junk pile from previous projects, I had some rigid insulation foam, softer foam rubber and some scrap 2x2. I figured this would work well as the main components.

I measured the shop vac dimensions, added a couple inches to each side for air circulation and the thickness of the foam.

This gave me the target outside dimensions. I went to the local home store and got two sheets of the cheapest 3/8" sheathing I could find. This is usually used under roofs and siding so it has a lot of visual imperfections, but it's good enough for this use and really cheap. When I got home I sliced up the sheathing and built the box by simply screwing it to the scrap 2x2. It's not pretty or square, but it does serve the purpose.

When I got the sheathing, I also picked up a piano hinge and some casters.

The casters I mounted on the bottom to make it easy to move around and of course I used the hinge for the door to give me easy access to the shop vac inside.

I mounted three spare electrical boxes in one corner on the inside. Two of the boxes go through holes to the back and the other points into the box. I'll get to the details of all that in a minute.

Next I cut up the foam and used spray adhesive to glue it to each of the sides.

Finally, I cut a hole in the side for the hose to run through and a hole in the top for the exhaust vent.

The electrical part has two components. A line voltage side and a low voltage side.

On the line voltage side, one of the boxes pointing to the outside has a male plug on it. This allows me to plug an extension cord into the box. This type of plug is convenient to use on projects like this but I couldn't find one at the normal places I typically get electrical parts. I ended up having to order this online. If you're looking for something like this, search for "flanged inlet receptacle". There's also an Amazon associate link in the description.

The box inside just has a normal duplex plug wired to the plug in the other box. The boxes are connected by a standard conduit connector. Combined, the two boxes provide a clean way to run power through the wall of the wooden box.

I plugged two things into the duplex outlet: a surplus low-voltage wall-wart power supply and this PowerSwitch Tail. The power supply provides low-voltage for the switch. The PowerSwitch Tail is basically a short extension cord with a relay built into it. When a low voltage is applied to these two connectors, it turns on the plug. This allows low voltage devices, like micro-controllers or other digital electronics to easily control line powered devices, like shop vacs.

I put another electrical box pointing to the outside for a remote switch. This is the low-voltage side. I installed a barrel style power connector in the electrical box pointing into the larger enclosure for the wall wart output to plug into.

On the outside of this box I installed a standard RJ-45 connector plate, like we used to use for those old-fashioned telephones. The connectors have four wires. The barrel power connector is attached to two of the connectors on the RJ-45 jack.

The other two lines of the RJ-45 run through the electrical box and go to the relay control connectors on the PowerSwitch Tail.

I then built a little switch box. It has an RJ-45 connector on the side and two switches: red and green. Inside it has a simple flip-flop circuit. Press the green button and the circuit turns on. Press the red button and the circuit turns off. A standard 4-conductor telephone cord connects the remote box on the side to the big box with the vacuum in it. I have a pretty long cord here that allows me to turn this on and off from anywhere in the shop. If you want more details of how this works, please leave a comment letting me know and I'll make another video about it. And if you're interested in the design evolution of this switch, there's a video on my second channel going into those details.

For plumbing, I used 2" black ABS drain pipe. This is pretty close to the diameter of the flexible hose that is standard on my vacuum. I ran a straight section across the ceiling with a couple sections running down in key areas in my workshop. I used sweeping connectors for smoother airflow and minimize places where dust can get caught. I held it all in place with perforated strapping tape and some screws. Most of the connections are just press fit. I didn't want to use cement in case I need to take it apart to clean it out, move it or do other sorts of maintenance. However, the sections that run down had a tendency to fall apart with just the friction fit so I put a short, self-taping screw in each one to hold them together. It's still pretty easy to remove the screw if I need to take them apart.

For the ports, I first looked at blast gates at the local wood working store. They were pretty expensive and not terribly well made. I really didn't think they were a very good value. I thought about making some blast gates of my own. I looked online and found some designs, but they were just more complicated to make than I wanted to deal with and I didn't have all the material I'd need in my scrap bin. So I made my own based on the design of the ports on the house's central vac system.

They're basically a hinged flap with a bit of foam to seal them and some magnets to hold them closed. They're epoxied to a standard plumbing fixture. The flex hose stays in with a press fit.

So that's pretty much it for the construction details. How well does it all work? I'll cover that in a future part 2 episode.

If you're interested in part 2 or other DIY type videos of this nature, click the Subscribe button and YouTube will let you know when they're released.

If you have any questions or comments, please leave them below. I'd love to hear from you.

Until next time, go make something. It doesn't have to be perfect, just have fun!

Wednesday, November 26, 2014

Bits of Binary: How to add binary numbers


Addition is probably one of the most common operations when using binary numbers. And it's really easy to do. We'll see how easy in this episode of Bits of Binary at the House of Hacks.

How to convert between decimal and binary.
Bits of binary playlist

For a written transcript, go to How to add binary numbers.

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Zap Beat" by Kevin MacLeod at


One plus one equals... huh? I'll talk about how this actually makes sense, today at the House of Hacks.


Hi Makers, Builders and Do-It-Yourselfers. Harley here.

In the last episode of Bits of Binary, I showed how to convert between decimal and binary numbers. In this episode in the series, we'll look at how to add binary numbers together.

Remember in grade school when you had to memorize this addition chart?

Well, OK, maybe you didn't have to memorize it, but I sure did.

This table is a matrix with the 10 numbers found in the decimal system, 0 through 9, on both the row and column headers. Each cell contains the sum of its row and column header. This gives us the sums for all the single digit combinations. 0+0=0 all the way up to 9+9=18. Multi-digit numbers can be added by simply thinking of them as multiple single digit combinations.

Well, binary has something similar, but much, much smaller. Since there are only two numbers in the binary system, 0 and 1, the table only has two rows and two columns. And it looks like this.

Or if you want to write it a slightly different way as equations, it looks like this.

Once you know this table, the process of adding in binary is exactly the same as adding in decimal. For example let's look at the decimal numbers: 321 + 181. Staring with the units: 1+1 = 2, 2+8 = 10 so write 0 and carry a 1, 1 + 3 = 4 + 1 = 5.

Similarly, in binary we'll look at 1011 + 10. Starting with the units on the right: 1 + 0 = 1, 1 + 1 = 10 so write 0 and carry a 1, 1 + 0 = 1, 1 + 0 = 1 again.

That's it. Addition is short and sweet. Thanks for watching this episode of Bits of Binary. In the next episode, we'll look at how to subtract binary numbers.

I've created a playlist over here that will be filled in as new episodes in this series are added.

Thanks to everyone who has subscribed to this channel and liked the videos.

Be sure to leave a comment if you have any thoughts or questions on this topic.

And until next time, go make something. It doesn't have to be perfect, just have fun!

Sunday, November 16, 2014

How to replace intermittent connectors


Sometimes plugs fail. Today at the House of Hacks we tear down a Better Life Devices BLD T250 transdermal stimulator to change the plugs from unreliable barrel connectors to more reliable 1/8" audio connectors. The general process can be used for any type of small device.

Referenced video: How to desolder electronics

For a written transcript, go to How to replace intermittent connectors.

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Dispersion Relation" by Kevin MacLeod at


This medical device is going to get an upgrade today at the House of Hacks.

My wife has chronic back issues and the other week had a big flair up. The chiropractor showed us a home electronic stimulation unit that he was willing to sell us at a very steep discount because he wasn't terribly impressed with their reliability. He said they worked fine as long as they worked but reported they had a tendency to develop intermittent faults and then fail altogether.

As I looked it over, before buying it, I noted the connectors on the side. A similar design used to be standard for photography flashes and is a well known failure point. I guessed that this was probably the problem but, if it wasn't, figured it would be easy enough to figure out what was.

So we went ahead and bought it, knowing I would probably have to fix it at some point.

Sure enough, after about two weeks of use it started working intermittently. In this episode, I'll show how I upgraded this with a more reliable solution.

At the local electronics store I got a couple 1/8" audio extension cords. The plan was to cut the ends off and put one end in the device coming out as a pigtail and splice the other end onto the wires for the pads.

But first I need to open the unit. I start by sliding this cover off, taking off the two knobs with a gentle pull, they're just press fit on, and removing the battery. It's a good idea to make sure the power is disconnected before doing any sort of repair on electric devices.

Next is to open it up. This took me a little bit to figure out as there are a couple hidden screws. The first one is under this label. Fortunately the label is made out of thick plastic and held down with some sticky but removable adhesive, so it peels off without too much trouble. Once off, a philips head screw is revealed.

There's another screw on the back under this belt clip. One side of this clip has a slot designed to slide a screw driver into. Lift up with a fair mount of pressure to pop off the clip. And there's the second screw.

Finally there are two plastic clips accessed through the battery cover. Pulling the two parts of the case apart at the bottom causes those clips to pop apart and the case finally separates.

The circuit board simply rests in place. To remove it, the LEDs may have to be slid out of the holes in the case before lifting the board out.

And that completes the disassembly.

These are the original cables with their problematic ends. They plug into these connectors on the board.

These will be replaced with the ends from this audio cable. I'll cut the ends off the cable and replace the connectors on the board with the female audio connector and splice on the male audio connector onto the end of the electrode cable. This will result in a much more reliable connection.

To remove the connectors, I'm just going to use a bit of desolder braid to remove the solder. Once the solder's removed, the connectors just drop out of the holes.

This is a cheap brand of audio cable that I've had about 50% failure rate with. So before doing anything to this cable, I'm testing it with a simple continuity check. I make sure I don't have any shorts between the tip and ring and that I do have continuity between the tip on both ends and the ring on both ends.

Now that the cable checks out, I'm just going to cut off the ends. Then using some wire strippers I'll carefully remove the insulation. With audio cables, the outside conductor is wrapped around the inside one. So after taking off the outside insulation, the wires first need to be gathered together and twisted. Then the insulation can be taken off the inside conductor.

And then the other end gets the same treatment.

With the connectors exposed and twisted together, now I'll tin the ends. This makes it much easier to solder when things are put together.

Now the wires just go in the holes the old connectors came out of. For this particular application, it doesn't matter which wire goes in which hole. For other types of devices, the outside ring should match up to the outside ring on the original.

A little solder finishes the connection and then the excess wire can be trimmed off.

That finishes the electrical side. Now a dab of hot glue makes a mechanical connection to act as a strain relief so there's no undue stress on the solder joint.

Now to modify the cables that plug into the device.

Cut off the original ends and split the two wires down the center. Expose the wire with some wire strippers, twist the wire together, add a bit of heat shrink tubing on the wires, add some tinning to the wires and solder the new ends onto the old wires.

Generally, I like to make a mechanical connection before soldering, but this particular wire was too brittle to bend well so I used the solder as both a mechanical and electrical connection.

Finally slide the heat shrink over the connectors and heat it up to shrink it around the connection. In total there were three pieces of heat shrink tubing for each cable: one for each of the wires and a larger one around the whole thing.

And now it's time to reassemble the device. This is just the opposite of taking it apart. Drop the circuit board into one side of the box, sliding the battery connectors into place. The other side goes back on top with the new connectors coming out of the original holes. The screws go back in. The label is replaced and then the knobs slide back onto the controls. Finally, the battery can be placed in. Before the clip goes back on, I'm going to test it. Yeah, nothing like testing it on yourself. As I turn up the intensity I can feel it working. Success!

A side effect of using these connectors is they act as a strain-relief, break-away connection. If the control unit somehow has forced applied to it, like it drops out of a pocket, it simply comes apart at the new connectors rather than putting a lot of force on the wire/connector/PCB system like the original connectors did.

Finally, I'm thinking about making a DIY version of this device. If you'd be interested in seeing a video about this, let me know in the comments.

Thanks for watching and until next time, go make something, it doesn't have to be perfect, just have fun!

Thursday, November 13, 2014

How to desolder electronics


Taking apart soldered connections is a handy skill for a maker. In this episode, we look at three techniques to do this.

For a written transcript, go to How to make desolder electronics

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Mining by Moonlight" by Kevin MacLeod at

Associate links

Paladin Tools 1700 Desoldering Tool With Standard Tip
Aven 17542 Desoldering Wick, 2.5mm Width, 5' Length


Today at the House of Hacks we're going to look at how to take apart electronics.

Hi Makers, Builders and Do-It-Yourselfers. Harley here. When working on electronics, a time will come when you have to take apart a solder joint. There are three main ways of doing this that we'll look at in this episode.

The first is to simply apply some heat and gently pull the connection apart. If you're just disassembling something without the need to put it back together and there's no mechanical connection, this works well. Like for scavenging these diodes and capacitors.

But this does leave a lot of solder on the connection so it may not work if you need to reassemble the joint. Also, if there's a mechanical connection, like wires that are twisted together, this may not work too well.

The other two ways physically remove most of the solder from the joint: the desolder pump, also known as a solder sucker, and solder wick or solder braid. Both these work well for connections that also have a mechanical component to them. Or electrical components with multiple points that all have to have their solder removed becoming apart. Like this LED sensor.

The desolder pump essentially vacuums up the liquid solder. There are a couple different designs, this one is spring activated, but they all basically work the same way. You push down the plunger, melt the solder, put the tip next to the connection and press the release button. This causes a vacuum in the tip and just pulls the solder right up.

Sometimes you have to do this a couple times to get all the solder out. Fancy solder stations may have a tip for the iron that has the suction mechanism built into it.

The desolder wick, or braid, works with capillary action on the melted solder. To use it, just put the braid over the connection and then heat it with the soldering iron. The braid will heat up, melting the solder and then capillary action will pull the solder up into the braid.

Depending on the size of the connection and the amount of solder on it, you may have to move to an unused spot on the braid a couple times to get all the solder out. It is a one time use tool. Once a spot of braid is full of solder, you trim it off and throw it away.

I originally learned with a solder sucker but recently started using the braid and I think it's becoming my preferred method of removing solder.

Thanks for watching and until next time, go make something. It doesn't have to be perfect, just have fun.

Monday, July 21, 2014

How to make a sewing table

Take a couple filing cabinets, some shelves made out of 2x8s and a 2x4 and end up with a new sewing table.

For a written transcript, go to How to make a sewing table

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Airport Lounge" and "Backed Vibes" by Kevin MacLeod at


[Harley] In this episode of the House of Hacks, I'm going to be making a table for my wife's new sewing machine from mostly recycled materials.

[Harley] Hi makers, builders and do-it-yourselfers. Harley here. My wife Diane is joining me today as a special guest.

[Diane] Hi. Harley recently got me a new sewing machine and serger.

[Harley] The new machine is designed for quilting and is much larger than the old one.

[Diane] So we had to make some changes to my sewing room for a new workflow.

[Harley] Part of these changes was to make a new table for her sewing machine.

[Harley] This project used mostly recycled items. My employer had a bunch of old stuff they were going to have a scrap company come in and haul off just to get them out of storage. They gave employees first crack at these items so I picked up a bunch of file cabinets designed for cubicles. We used two of them in this project for storage and support on one side.

[Diane] Almost 30 years ago I made some shelves out of 2x8s. They served their purpose well but no longer fit our needs, so we cut them up and used them as the top and one side. A couple 2x4s, bolts and washers were all we purchased. The total project cost was less than $16.

[Diane] Here are the highlights from that project.

[Highlight reel]

[Harley] I hope this project inspires you to use things in slightly different ways than they were originally intended to meet changing needs.

[Diane] Obviously if you need to build a sewing table, what you have available will probably be different from what we had, but perhaps you can find something appropriate to accomplish your task.

[Harley] Thanks for watching. If you enjoyed this overview, I'd appreciate knowing about it with a "like."

[Diane] If you have any thoughts or questions, Harley would love to hear them in the comments below.

[Harley] Until next time, go make something. it doesn't have to be perfect, just have fun!

Thursday, July 10, 2014

Bits of Binary: How to convert between binary and decimal

Learn how to convert from binary to decimal numbers and from decimal to binary numbers.

There's a written transcript for How to convert between binary and decimal.

There's also a playlist for all the Bits of Binary episodes.

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at


If you don't get this classic joke, by the end of this episode you should. Today I explain how to convert binary to decimal, and back again, here at the House of Hacks.

Hi Makers, Builders and Do-It-Yourselfers. Harley here.

In the last two episode of Bits of Binary, I introduced alternate number systems in general and the binary system in particular. Next I showed how you can use binary to count much higher than ten on just your fingers. I closed with the question "How high can you count in binary on both hands?" If you came up with the answer 1023, you really understand the basics.

In this episode in the series, I'm going to show how to convert from binary to decimal and from decimal to binary.

Last time, I explained how each column in a number is the base number raised to a power times the value of the column. That sounds more complicated than it is. In our familiar base 10, or decimal, system, the columns are 10^0, 10^1, 10^2 and so forth. This gives us columns that represent units, tens, hundreds and so on. To get a specific number, say 123, you simply multiply the number in the column by the column's value. Or (100 * 1) + (10 * 2) + (1 * 3). Applying this principal to binary, the columns are 2^0, 2^1, 2^2 and so forth. Giving us 1, 2, 4, 8 and on up.

So, let's convert from binary to decimal. What's the decimal value of the number 10101? Given that each column represents a power of two and each column can only have a value of 0 or 1, this means its value is (2^4 * 1) + (2^3 * 0) + (2^2 * 1) + (2^1 * 0) + (2^0 * 1). Removing the items multiplied by zero gives us (2^4 * 1) + (2^2 * 1) + (2^0 * 1). Evaluating the exponents gives us (16 * 1) + (4 * 1) + (1 * 1). And all this simplifies to 16 + 4 + 1 or 21 in decimal.

Now that we know the theory, let's look at some shortcuts. Instead of looking at the columns as 2 to a power, we can look at them with specific values. Starting with the units column, we know it's one. Each subsequent column is the current column times 2. This gives us 1, 1 * 2 is 2, 2 * 2 is 4, 4 * 2 is 8, 8 * 2 is 16 and so on. Next, all we need to do is write the binary number below the numbers: 10101. And then simply add the values of the columns with 1's in them. 16 + 4 + 1 = 21 decimal.

Binary to decimal is really pretty simple.

Next, let's convert from decimal to binary. This is slightly more complicated, but still not hard.

We need to start with a binary column value larger than our decimal number. So, we start at the right side with one and multiply by two until we have a number larger than what we want to convert. Then working from the left we apply this rule: if the value we want to convert is greater than or equal to the column value, then we set a one for that column and subtract the column's value, otherwise, we set a 0 for that column and continue. The result is then applied to the next column. And we apply the rule until we reach zero.

Let's try the earlier example of 21 decimal. First, find the columns. Start with 1 and double until we have a value greater than 21. Then start from the left and apply the rule. 21 is less than 32 so we write a 0 and move to the next column. 21 is greater than 16, so we write a one below the 16 and subtract 16 from 21 leaving us 5. Next column. Five is less than 8 so we write a zero below 8 and move on. Five is greater than 4 so we set a one below the four and subtract four from 5 leaving us 1. One is less than 2 so we set a zero below the 2 and move to the units. One is equal to one so we set a 1 in the units column, subtract 1 from one leaving us zero and we're done.

If we get to the end without reaching zero, we've done something wrong and need to recheck our work.

Looking at the binary value, we have 10101, which is what we saw in the previous example of binary to decimal, so it all works.

Let's try 24 decimal as another example. 24 is greater than 16, so we set a one below the 16, subtract 16 from 24 leaving us 8. 8 is equal to 8 so set a one below the 8 and subtract 8, leaving us 0. Since we know 0 is less than all the other columns, we can just set them to 0 and be done. This leaves us 11000 binary.

That's all there is to convert between binary and decimal.

I've created a playlist over here that contains all the episodes in this series so far and will be filled in as more are added.

Thanks for watching and if you learned something, I'd appreciate a thumbs up If you have any questions or comments, leave them below. I try to respond to all of them.

So until next time, go make something. It doesn't have to be perfect, just have fun!

Monday, May 5, 2014

How to drill holes for cam lock connectors

Discover the spacing and sizes of the holes in order to use cam lock connectors in your next project. Cam connectors provide a clean and secure, but easy to disassemble, joint for boards. In this video, I provide the drill bit sizes and hole spacing for commonly found cam locks.

For a written transcript, go to How to drill holes for cam lock connectors

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at


Want to learn how to drill the holes to use cam locks? I'll show how here today at the House of Hacks.


Hi Makers, Builders and Do-it-yourselfers. Harley here.

On a recent desk project I thought it'd be interesting to use cam locks for part of the assembly. It was in a couple areas where I didn't need huge amounts of strength and I wanted clean lines and easy disassembly. Cam locks seemed like a good solution.

If you're not familiar with them, cam lock connectors are a two part fastener that looks like this. They're used to connect two flat pieces together at a 90 degree angle. Things like the sides of book cases, or, in my case, a side support to a table top. There is a post that screws into the flat side of the first surface and slides into a hole on the end of the second surface. A cam lock slides into a hole in the surface of the second piece and locks onto the top of the post, pulling the joint together as the cam locks into place.

I have only seen them used in pre-cut furniture that's designed for home assembly, but I knew I could get them at my local home center. So I went down and picked some up. I did the next logical thing and searched around the internet to find out the hole pattern. Obviously I knew I needed several holes. I just didn't know the spacing and the sizes. Surprisingly, I didn't find anything on the internet. So I sat down to figure it out.

The home center had two types of posts: one had wood screw threads and the other had machine screw threads. I used the ones designed for wood. Both thread types came in only one size and it seemed about the same as all the other's I've seen in furniture kits. I don't know if the connectors come in different sizes or if there's pretty much only one standard. In any case, the bags for the ones I had were marked with "M6 x 45.5" for the connector bolts and "15mm x 16mm" for the cam connector. The details I present here are for these sizes.

All my bits are in imperial measurements, but the tolerances are close enough they worked just fine in spite of the metric hardware. I used a drill press for all my holes to help ensure straight holes and a good fit. If you don't use a drill press, do your best to get the holes as straight as possible.

For this project, three bits are needed: 3/16" and 5/16" in a twist or brad pointed bit and a 5/8" Forstner bit.

Use the 3/16" bit to drill holes for the posts to screw into. The depth isn't terribly important as long as it's deep enough for the post to screw in securely up to the shoulder of the thread. I found 7/16" deep worked well.

Before putting the posts into the hole, I transferred a mark to the other piece. It is fairly critical to get these holes correctly aligned as the post has to go into both of them. I didn't have any dowel centers small enough so I found a self-tapping screw in the surplus screw box with an outside thread diameter the same as my hole size. I cut it to a little over 1/2" long and set it in the hole, pointy side up. I used it to mark the center of the matching hole in the other wood. Then the post could be screwed in.

Next I drilled the holes in the end piece using the 5/16" bit. The holes need to be a bit over 1" deep. Again the depth isn't critical as long as it's long enough to go into the area where the third hole will be drilled.

Finally I drilled the hole in the side for the cam nut. Here I used the 5/8" Forstner bit. This hole is the most critical of the three. The center positioning needs to be pretty precise for the cam to engage properly. Its center is the same as the one on the edge and it's 1-5/16" from the edge. This puts the edge of the hole right underneath the top of the post. If it's too far from the edge, the cam won't engage and if it's too close to the edge the cam won't tighten against the wood.

Its depth will vary depending on the thickness of the material and where the post is relative to the surface. It needs to be about 4mm deeper than the distance the centerline of the post's hole is from the edge.

Once the holes are all drilled it's ready for assembly. The post is screwed into the first piece. Make sure to get it in straight and don't over tighten it, but get it snugged up to the shoulder. Now, the two parts just slide together. Finally, the cam is put in with the open side towards the top of the post and given a 180 degree turn with a screwdriver. If everything is done properly, it should lock down tight.

I'd recommend getting two pieces of scrap material to practice on. Once you've done it a time or two, it's easier to proceed with confidence on the main project pieces.

I'm pretty pleased with the way this worked. It took a bit to drill all the holes but it provides a nice clean joint that's secure and easy to take apart for storage or moving.

Thanks for watching and until next time, go make something. It doesn't have to be perfect, just have fun!

Tuesday, April 8, 2014

Bits of Binary: How to count in binary


For a written transcript, go to How to count in binary

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Feelin Good" and "Cold Funk" by Kevin MacLeod at


If you recognize this as the number 31, you can skip this video. But if you want to know how to count to 1023 on just your fingers, we'll find out in this episode of the House of Hacks.

Hi Makers, Builders and Do-It-Yourselfers. Harley here.

In the last episode of Bits of Binary, I talked a bit about different binary systems in general and binary numbers in particular. You can click here if you're interested in this introduction.

In this episode, I'll start with the basics of decimal numbers that you may already know. I'll then relate that to alternate number systems in general and then binary numbers specifically. Finally I'll wrap up with how to count in binary.

When we were young, we learned to count on our fingers: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

A couple years later we learned there's actually a special value that's no quantity: 0. And and with this new knowledge we found that 10 really isn't a number in the same way as the other nine are. It's a combination of 1 and this new non-value value. We found that at the core, we have 0 through 9 as our ten digits, not 1 to 10.

While were were still reeling from this new information, we learned you can count the groups of 0 through 9 and keep track of that in the "ten's column." So, now we could have 10 through 19 and 20 through 29 all the way up to 90 through 99. And then we could add a "hundreds column" for 100 through 199 and so forth. Numbers could actually be arbitrarily large by just adding another column.

This was mind blowing!

There were numbers incomprehensibly large to our young minds like "million" and "billion" with all kinds of crazy numbers of columns.

Then as we grew and got more sophisticated, we learned about something called exponents. These columns we were so comfortable with could now be represented by 10 raised to number of the column. So the "ten's column" was 10^1 and the "hundred's column" was 10^2. The "unit's column" took advantage of a weird property of exponents that said "anything raised to the power of 0 is 1."

It was explained any number could be split into its constituent parts by taking the digit in each column and multiplying it by the power of 10 for that column and adding the results together for the other columns. We found the simple columns we learned early in our education were just shorthand for much more heady concepts.

For example, the number 123 could be written (1 x 10^2) + (2 x 10^1) + (3 x 10^0).

If you're anything like me, this is about where the educational system stopped. There was no direct talk about this "5" being an abstract symbol for an underlying value. They did talk about it in an oblique way when they talked about other cultures having other number systems such as Roman numerals I, V, X, L and C. But that was about it. It was simply given that "5" meant "*****" this many things.

This was the decimal number system and how those of us now middle aged in the United States probably learned it.

If you had your young mind blown when you learned the ten's column was 10 raised to 1 and the hundred's column was 10 raised to 2, here's another mind blowing revelation...

The column base, the 10 so far, doesn't have to be limited to the number 10. It can be any anything!!

For example, this base could be 16 where you'd have the familiar zero and 15 other symbols. In this base, this many objects "**** **** **** ****" would be written as 10. Even though it looks like ten, it isn't. It's sixteen. And if you add one more "*", it'd be written 11 meaning seventeen.

Or the base could be 8 where you'd have zero and 7 other symbols. In this case the quantity seventeen would be represented by the series of digits 21. But in decimal, it'd still be represented by 17 and in base 16 it'd still be 11.

When dealing with multiple number systems at the same time, typically we put a subscript after the number to indicate the base for that number. So in the example of seventeen items, the previous bases would be written as 11(16), 21(8) and 17(10). This helps reduce confusion. But typically only one system is used at a time, and the base is left off, since it's implied by the context.

As you're trying to get your brain around all this, let's talk specifically about today's topic: binary. Its base is 2 so all we have is zero and one other digit: 1. That's it. 0 and 1, 1 and 0. Easy!

Let's look again at the columns we learned about when we learned about exponents. Just like in decimal where column one was 10 to the 0 and column two was 10 to the 1 and column three was 10 to the 2 and so on, in binary column one is 2 to the 0 and column two is 2 to the 1 and column three is 2 to the 2. That means the value of these columns if we multiply them by 1, are 1, 10 and 100 for decimal. And for binary they are 1, 2, 4, 8 and so forth.

Going back to our earlier example, in decimal, for each column's power of ten, you can multiply it by a number from 0 to 9, because your base is 10.

Binary however is much easier. For each column's power of two, you can only multiply it by either 0 or 1, because that's all the digits we have.

So, let's see what happens when we count from 0 to 10. For comparison, let's see both decimal and binary side by side. 0. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

See this pattern...

If we use a finger to indicate one and apply this pattern to our fingers...

zero, one, two, three, eight, nine, ten.

By continuing this pattern, on one hand we can count to the number 31. This is 16. Plus 8. Plus 4. Plus 2. Plus 1. That totals 31. So, how high can you count using both hands?

Thanks for watching this episode of Bits of Binary. In the next episode, we're going to look at how to convert back and forth between binary and the more familiar decimal numbers.

And I've created a playlist over here that will be filled in as more episodes in this series are added.

If you liked this, let me know by hitting the "like" button.

If you are already a subscriber, "thank you!" but if you aren't, be sure to "subscribe" so you don't miss future videos.

I'd love to hear from you in the comments below if you have any thoughts or questions on this topic.

Until next time, go make something. It doesn't have to be perfect, just have fun!

Friday, March 28, 2014

How to make artificial wind

For Arduino Day 2014, I show how I solved the problem of enjoying wind chimes when there's no wind. Using an Arduino of course.

For a written transcript, go to How to make artificial wind.

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at
Incidental: "Feelin Good" and "Cold Funk" by Kevin MacLeod at


Today at the House of Hacks, I'm going to try to make some artificial wind.

Hi Makers, Builders and Do-it-yourselfers. Harley here.

Over the years we've been give a couple wind chimes that are really nice. They're tuned to specific chords to be really full and resonating. They've got some beautiful wood on them and they're just too good to put outside in the weather and get all beat up. So we have them hanging here in the corner of the living room. During the summer they work really well. We open the house up and the breeze comes through, particularly the evening breeze, they fill the house with nice chimes. During the winter we close everything up and we just don't get to enjoy them. We've tried using an oscillating fan and haven't really been able to get this to succeed very well. The fan itself is very loud and makes a lot of noise. And we haven't been able to get it adjusted so that it has the right amount of turbulence to ring the chimes in a way that sounds pleasant, it's either not enough or too much.

I've had an idea floating around in the back of my mind for awhile to do this electronically. I thought this was a good time to try to do this. March 29th is Arduino Day. It's hard to believe that Arduino's been around for 10 years, but this is its 10 year anniversary--10 year birthday. I thought this would be a good opportunity to do a project that featured an Arduino and also solved a problem that I have. So let's go down to the workshop and see what we can dream up.

The idea I've had floating around in the back of my mind now for awhile is to take an Arduino, connect it to a servo motor and on the servo motor attach a pulley. To the pulley attach some monofilament thread and connect the other end of that to the wind chimes. So, when the pulley turns, it pulls back the wind chimes and then it releases them and they can swing. The Arduino gives us the ability to add some randomness in there to pull it back different amounts, to release it at different speeds, things of that nature, to give us some randomness and hopefully give us a nice pleasing sound that we have some control over.

I think what I want to do is have a total of 12 inches that it pulls on the monofilament thread. And I want to do that in a quarter turn of the pulley. That means the pulley circumference needs to be 48 inches. To get the radius to make the pulley we have the 48 equals 2 pi R. We need the radius so we divide 48 by the 2 pi. Well pi is pretty close to 3 for round numbers and that gives us 48 divided by 6 which gives us a radius of 8 inches.

So let's go build this.

A thin strip of scrap wood fills the need perfectly for an ad hoc 8 inch compass.

I mark the boundaries of the center based on the outside dimensions of the cardboard.

The center of the circle needs to be inside these bounds.

And now just draw the circle.

I cut the cardboard freehand around the marks. I needed 3 disks in total.

Since this is just a prototype, proof-of-concept, scrap cardboard and some hot glue make fast and cheap building materials.

Mark the direction of the corrugations so when the disks are glued together they can be rotated 90 degrees to each other. This will give them some strength.

Three circles, one slightly smaller than the others will make a rough pulley.

I've found hot glue is a great tool for fast construction.

Now I need to find the center. If I'd been thinking I could have placed the other side up and had the hole from the compass already marking the center for me.

A dab of glue attaches a small servo.

The servo is mounted in a hole cut to its size.

A couple weights holds the cardboard tight to the motor mounts while some glue is applied.

A spare piece of Romex wire will work as a mounting bracket for the Arduino.

The wire just slides into the corrugations of the cardboard.

And holds the Arduino in place.

The circuit is simple. The servo connects to the breadboard. To connect the servo to the Arduino, the yellow data wire goes to pin 9, the brown ground wire goes to ground and the red power wire goes to 5 volts.

And it's ready to test.

Load the example servo to sweep a 180 degree arc and upload it to the Arduino.

Fail!! It worked a couple times and then stopped. Something broke. I had to help it get unstuck on one side.

So I needed to swap motors. The first one I tried had a 1.6 kg/cm torque rating and plastic gears. The replacement is rated for 3 kg/cm and has metal gears. It's also quite a bit more expensive.

So I used screws to mount it instead of glue.

I still used glue for the pulley though.

And this works much better. No manual intervention required.

A dollop of hot glue holds the monofilament string in place.

Another piece of bent Romex wire acts as a guide for the string.

Load a slightly modified version of the sweep example.

And a real test…

Yay!! It works!!

For a hacked together prototype, I'm pretty pleased with the way this turned out.

If you're interested in seeing this prototype turned into a finished project, let me know down in the comments below what it is you find fascinating about this project, what you'd like to see in a follow-up video, that type of thing.

Until next time, go make something. It doesn't have to be perfect, just have fun!

And finally "Thank you" if you've already subscribed. You can configure YouTube to notify you when new episodes are available. If you aren't subscribed and you want to get those notifications, be sure to subscribe. It's free and contains zero calories. Finally, if you're interested in this series, go ahead and hit the "like" button, that'll let me know there's interest in this.

Thanks for watching and until next time, go make something. It doesn't have to be perfect, just have fun.

Tuesday, February 11, 2014

Bits of Binary: What is binary?

What do Morse code, Braille and binary numbers have in common? Find out in this introductory episode of the new Bits of Binary series.

Bits of Binary playlist

For a written transcript, see House of Hacks.

Music under Creative Commons License.
Intro/Exit: "Hot Swing" by Kevin MacLeod at

Photos in public domain:

What do Morse Code, Braille and binary numbers have in common? Let's find out today at the House of Hacks.

Hi Makers, Builders and Do-It-Yourselfers. Harley here.

As I think about different videos I want to do in the future, certain areas of knowledge seem to recur. They're somewhat foundational. I plan on doing a couple series on these foundational topics. But don't worry. I'm not going to do them exclusively. I'll intersperse them with my normal projects and other tutorials. This is the first episode in the first of these series. And now, to the topic at hand.

Morse code uses short signals called dits and long signals called dahs in various combinations to encode letters, numbers and other symbols. The dits and the dahs can be represented by long and short sounds, or blinking lights or any other method of indicating two states.

For example, this is the letter "A." And this is the letter "B." And here's "Hello world."

The interesting thing here is there are two things, a dit and a dah, in the context of silence to separate letters and words to communicate.

Braille uses a two by three grid containing various patters of raised to encode letters, numbers and other symbols.

For example, this is the letter "A." And here's the letter "B." And here's "Hello world."

Braille is used predominately to allow blind people to communicate in written form. Interestingly, it was adapted from a similar system used by the French military to communicate on the battlefield without using sound or light that might give away their position to the enemy. So, it doesn't have to be used exclusively by the vision impaired. But that's a bit of a historical side note.

The important thing for the purpose of this discussion is to note it uses either the presence or the absence of a raised dot. A bit of information, in the context of other bits of information, the two by three grid, to convey more information.

Binary number systems use just zero and one to represent numbers.

For example, this means one. And this means two. And this means ten.

Computers use either the presence or absence of a voltage to indicate either zero or one. And they build sequences of these up into numbers to represent symbols, numbers and letters.

So, what is binary?

Simply, binary is defined as something having two parts. Each of these systems we've talked about today use just two things, within a context, to encode information. Morse code uses sequences of dit and dah. Braille uses the absence or the presence of a dot within a grid. And binary numbers use zero and one within a sequence.

In future episodes in this series, I'll be discussing binary numbers in more depth. How to correlate them to the decimal system you're probably already familiar with and how to perform mathematical operations on them.

There's a playlist over here that will have new episodes added to it.

And finally "Thank you" if you've already subscribed. You can configure YouTube to notify you when new episodes are available. If you aren't subscribed and you want to get those notifications, be sure to subscribe. It's free and contains zero calories. Finally, if you're interested in this series, go ahead and hit the "like" button, that'll let me know there's interest in this.

Thanks for watching and until next time, go make something. It doesn't have to be perfect, just have fun.