In Part 1 I did the cutouts for the two sides of the MiniMAME cabinet. This photo gives you a better idea of how the unit is going to look:

It stands about 24″ high, 19″ wide, and 16″ deep. It will handle a 20″ Dell 2001FP LCD monitor.

There is not enough depth for a CRT. I did this on purpose, since I knew I would be using an LCD and not a CRT. The original plans are designed for a CRT installation, so they are deeper. The original plans also have vertical space for a coin slot (they are quite a bit taller). I modified the plans to suit my specific purpose. However, I did leave enough space in the control area to handle a joystick.

Here is the front-view. You can see that three 18″ 2×4s are used as supports. They tie the two halves together.

It’s critical that those 2×4s are cut PERFECTLY straight, otherwise the unit won’t be square and level. This is a big reason why I got the miter saw. I suck at cutting straight lines. I first cut the pieces with my small circular saw (the 5 1/2″ trim saw) and nothing was straight. I would have been better using my 7 1/4″ saw, but I needed blades. Either way, my new miter saw is so much better at cutting the angles. It’s going to be put to good use on this, and other, projects.

Next up: Building out the front, top, and back “body” parts. Lots of MDF cutting. Get the vac and dust mask ready.

In the second photo you can see that the cabinet is sitting on a Black and Decker Workmate portable workbench. Evelyn picked this up at a local thrift store. I LOVE this folding portable workbench. It stores away when you don’t need it, and is perfect for cutting wood, setting up projects, and so on. It was a great find. And, luckily, it’s an older model, which means it’s all steel and wood–very little crappy plastic.

It’s inexpensive ($99) and it works. It’s already been put to good use on our Super Secret Kiosk project.

Well, it’s bulk pickup week in our neighborhood. This means that the streets are flooded with overloaded pickup trucks filled with peoples’ cast-offs. Grills, cabinets, snowboards (in Texas?), monitors, and all sorts of junk. I don’t know why the city even bothers sending a truck around, since ALL of the good stuff is picked pretty quickly. Maybe they should just announce a bulk pickup and let the junk guys do the rest. That would save the city some money.

Alas, there is a Single Sad Sentinel which is ignored by all of the junk guys. I give you, the neglected toilets:

There are toilets EVERYWHERE. It’s as if there was a big Digital Toilet Switchover and everyone got rid of their old thrones. Pretty sad. If only there were some way to re-use these things. I’ve seen people use them as planters, but they look pretty stupid that way. Ah, well. Another pile of porcelain for the landfill.

We are currently working on a couple of Big Super Secret Projects. One of them requires a computer kiosk-like setup. I quickly realized that the best design for this is an arcade game type cabinet. I didn’t need some full-size unit, since this is going to be table-top, but fortunately a group of people have already make smaller units.

Here is the template I started with (sorry for the blurry photo, I didn’t realize the camera was on manual focus):

This design is from the MiniMAME site. If you are interesting in making your own MAME cabinet, on the small (cute) scale, take a look. MiniMAME Site You can also find a lot of plans for full scale cabinets, if you you want to have your own home arcade.

MAME stands for Multiple Arcade Machine Emulator. When used in conjunction with images of the original arcade game’s ROM and disk data, MAME attempts to reproduce that game as faithfully as possible on a more modern general-purpose computer. MAME can currently emulate several thousand different classic arcade video games from the late 1970s through the modern era.

My cabinet is going to be dual use. First, I wanted something for my Super Secret Project. Second, I wanted it to be able to act as a MAME cabinet, in case Super Secret ending up being a Super Disaster. Always good to have a Plan B.

My cabinet will be using an LCD screen, so I didn’t need as much depth. It also didn’t need to be so tall, since I wanted the screen at eye level when sitting on a typical table.

I had a couple of sheets of pre-cut MDF sitting around. They were 25″ high and about 48″ long. There was my target height–make the cabinet the size of the materials on-hand. As luck would have it, that size is good for a 20″ or smaller LCD display (measuring about 18″ wide and 14″ tall).

Here is what I ended up with, drawn on the MDF:

Take advantage of factory cuts. In my design the bottom, back, and most of the top run along factory (or panel saw) cut edges. This means that those lines are perfectly straight. Save yourself time and use factory edges when you can. Or have the folks at Home Depot or Lowe’s cut the pieces on their panel saw. It will be far more accurate than you can get with most home tools.

The hardest cut, a plunge, is where the monitor opening will be. This is a very dangerous cut, since you have to plunge a circular saw blade right into the middle of the wood. As an added challenge, you need to do BOTH sheets at once. Otherwise you’ll never get them lined up. In the photo above you can see the three screws I used to lock the two sheets of 3/4″ MDF together so they won’t shift.

You need to use a circular saw for this process. A jigsaw is not going to give you an accurate enough line, since the tip of the blade wobbles slightly. I used my little 5 1/2″ battery powered trim saw. It’s underpowered for this job, but is a LOT easier to work with for this tricky, and short, cut.

To do this cut you first have to clamp a guide to the workpiece. This is what the saw will rest against as you plunge it into the wood. The clamp is 1″ from the line, because the base of my saw if 1″ from the blade (the trim saw has the blade on the LEFT–most full-sized saws have the blade on the RIGHT–measure your saw–it will be different from mine).

I used a spare piece of 1×2 36″ red oak as my guide, since it was the right size. You can use a piece of moulding, or anything else that has a little height and is straight. I have the guide clamped in two places, and the whole assembly clamped to my portable workbench.

Here you can see the cuts in progress. I did the tricky plunge first, then some of the corner work. I left the back corner for last, since it was an easy cut, and I wanted to take advantage of its screw (holding the two pieces of MDF together).

If you look carefully at the plunge cut (nearest the ruler), I screwed up a little bit. One part, where I plunged, is a bit thicker because my saw bound up in the cut. A little sanding will take care of it.

Since the blade is circular, you can not get into the corners. For this project you can’t overcut, so you need to get as close as you can, then finish up with a jigsaw or a handsaw. Since there was so little to cut, I used a handsaw. It gave me the control I wanted, and made quick work of the corner. Here’s what it looks like all cut out:

There were some saw marks where my little portable saw bound up, and some of the edges weren’t exactly right (because the original wood was not straight on one edge). I don’t have a power sander handy, so I went at it to old fashioned way: sandpaper and muscle. As you can see, it cleaned up pretty well:

After I did the hard part, I clamped everything together and did the final cut–the rear top corner piece. You need it clamped down, since you are cutting through the remaining screws holding the two pieces together.

Next up: Putting the sides together.

After our success with the Skill Share class we held, we started thinking about the next project. One idea we came up with is a Cigar Box Guitar. We figured it would be something that could be put together without a lot of hand tools, was pretty inexpensive, and would be a good “Austin vibe” project.

So, a couple of weeks ago I picked up some Red Oak from Home Depot so that I could start the project. Unfortunately, hardware (screws, bolts, etc) is MUCH more expensive at the big box home stores. A pack of 25 1/4-20 nuts is a couple of bucks at Home Depot — I could get a box of 100 for the same price at Grainger! So I placed an order for some of the hardware (eye bolts, nuts, washers).

If you are building projects I highly recommend that you get used to buying quantites from places like Grainger and McMaster-Carr. You’ll save a LOT of money in the long run. McMaster is very good, but I also like Grainger because they have retail locations where you can pick up your parts (on “will call”). We have a Grainger about 5 minutes away from us, and they offer free shipping for order over $50.

After my 10 pound box of eyebolts and washers and nuts arrived, I was able to start on the guitar. Here’s a shot of the head of the guitar, where the tuning is done:

There are six holes up there. Three for the eyebolts, washers, and wing nuts. Three more for where the strings are threaded. There is a small piece of 1/4″ square stock super glued to the neck of the guitar. This is called the “nut” and the strings will rest on it.

Here is a view from the underside, where you can see the eyebolts. The strings will be attached to them and the whole assembly twisted and tightened to tune.

So, you have eyebolt, nut, washer, then wood, then washer and wingnut. Make sure to use STRONG wood for the neck! Red oak is good. This piece is 36″ long.

Toward the bottom you have the bridge. There are six holes down here. Three are where the strings are threaded through, the other three will hold screws or bolts for fastening the ends of the strings. These are fixed points.

This is also the location of the bridge of the guitar, which is a piece of 1/2″ sqaure stock super glued to the neck.

I’ll be using #18 mason’s twine for the bass string, and #15 for the other two strings. (This will be a three string guitar.)

Next up: Finding a good cigar box that doesn’t cost an arm and a leg. For some reason, people are selling these boxes for stupid prices ($8-$10). You should be able to get one for about a buck or so. Evelyn is going to check out our local tobacconist and see if they are willing to part with some. I need one for this project, but probably 20 or so if we do this as a class project.

Here’s a little project that I worked on a couple of weeks ago. Its from a very early issue of Make magazine. There’s also an Instructables here: Mousebot Revisited

First you need to take apart your mouse. I have a bunch of old junk mice laying around. Make sure you get a mechanical “ball” mouse, and if it has a scroll wheel, even better. Get one that is symmetrical. Here is the mouse in pieces:

You have to then trim out the insides of excess plastic, so that you have room for a battery, motors, and the circuit. In this photo you can see that I used a Dremel to remove the mouse ball’s “cage”:

I drilled holes for the motor shafts, and carved out a space up front for a microswitch (the “bump” switch). The motors got mounted with hot glue, and are sitting on a piece of Komacel (you can use anything that’s the right thickness and strength).

Here are the “eyes” of the little robot. Two IR photosensors (you can use new, like I did, or scavenge from the mouse) and a green LED. I used solid wire to give them stiffness and then put heat shrink tubing to a nicer look.

Here’s the mouse wired up. The original design uses “dead bug” wiring — where you solder directly to the pins. This seems the easier route at first, but could lead to shorting of components in such a tight space. Next time I would use a protoboard. For this one, I had to carefully tape any wires that might touch.

Here is a close-up of the front. From right to left you have: bump switch, motors, circuit (LM 386, relay, transistor, capacitor, resistor), then the battery. On the “lid” (top) of the mouse I have mounted a power switch and the eye “stalks” along with the green power LED.

Here’s the outside view of the almost-done mouse robot. You can see the little power switch I used as the “tail” toward the left of the photo:

The little brain inside the robot (actually just an amplifier) compares the light levels from the two eye stalks. It then heads in the direction of the brightest light. If it runs into something, the bump sensor will reverse the robot for a few seconds, and then it starts hunting for light again. These types of robots are often called “photovores” because the “eat” light.

If you are in the market for tools, in particular power tools, now seems to be a good time to buy.

We’ve been looking for an inexpensive, but decent, miter saw for the shop. One project I’m working on in particular needs nice accurate cuts, and I couldn’t do them properly with my small circular saw. (As usual, I am vexed by simple tasks. I can make complicated plunge cuts in a big piece of lumber, but I can’t cut a 2×4 accurately if my life depended on it. Go figure.)

We went to Lowe’s yesterday to pick up more lumber and saw blades, and Evelyn spotted a good deal on a Skil miter saw — $99 for a 10″ model. It’s not the biggest, most powerful, saw out there. But it was a good deal for our small-scale (non-production) work. It was a breeze to set up, isn’t too heavy, and did exactly what I needed it to do. Horray!

Today I received an e-mail from Amazon with sales on routers, another device we’ve been needing for a while. I was able to pick up a small Milwaukee router, with fixed and plunge base, with a case, for $126 shipped. Again, it’s not a big powerful router, but it’s perfect for the work that we do.

We’ve been seeing quite a bit of this trend: Good introductory power tools at very reasonable prices. It’s actually kind of shocking, since we’re getting good deals on new power tools, while on the other hand our local thrift shops have gotten MORE expensive! Explain that to me.

Now I just need more bench space.

When Deb was visiting we went out west toward Hill Country. Tried to stop at a BBQ place in the tiny town of Bertram, but couldn’t find it (or it was closed). I knew of another place in Llano, further west, so we headed there. The place is called Cooper’s and shows up on the Texas Top 50 BBQ places and was recommended by our native Texan neighbors.

Here’s the outside pit area:

You start by going up to the pit have choosing what meat you would like:

It’s a good mix of Texas BBQ (beef) and some really good pork, too.

Going from the lower left, clockwise, you see: Pork sausages, beef ribs, chicken halves, more sausage, brisket, roast beef (and more brisket), pork loin, turkey, huge pork chops, and finally the pork ribs.

Mmm meat:

Above is a closeup of the chicken and beef. Below is the pork. Look at the size of those pork chops (the three toward the front).

What you do is point out what you’d like, and how much. The pit master takes a tray and starts piling meat on it.

You then take your tray inside and give it to the folks behind the counter. They then weigh it (it’s a per pound cost, between $8 and $10 a pound) and wrap it up for you. You can also pick out sides (corn, desserts, etc).

As you move down the line the checkout person gives you a big piece of kraft/waxed paper (that’s your plate) to eat off of. You then pay for your stuff, and head toward the pots of beans and onions and sauce. Once you’ve got all that, you find a place to sit on the long picnic benches. No personal tables here, just long benches with paper towels and loafs of cheap white bread. It’s time to meet your neighbors. We managed to find a spot at the end of one of the tables, sitting in a room of locals just enjoying their lunch.

We got the pork ribs, beef ribs, brisket, pork loin, and sausage. Brisket was very good, beef ribs were very beefy (which I like), and the pork was excellent. Some of the reviews had mentioned that the meat was dry, but we had no problems with ours. It was very juicy.

So there you are, sitting at an inside picnic table, with a room full of Texans, eating off a piece of paper, with a big pile of meat in front of you, a bowl of cowboy beans, and a Shiner Bock ready at hand. No cloth napkins. No waiter. No pretention. Just good honest food.

Oh man, this has to be my New Favorite Site Of The Week.

There, I Fixed It

It’s cool to see that people are making their own coat hanger DTV antenna. A couple of questions have come up, which I put in Comments, but wanted to also include on the main site:

Question: Does more “bow ties” mean more gain?

Answer: The more bow ties you add, the more gain you will get. I don’t have my antenna book handy, so I can’t say what the limit is, but increasing element count is a good way of getting weaker signals. If memory serves it’s a logarithmic function, so doubling elements won’t double gain.

Question: There are some stations that are still broadcasting in the VHF band. What do I do?

Answer: The length of the elements themselves determines the frequency they are best at picking up. If you still have some VHF, then you can try a couple of things:

• The simplest would be to scavenge some old “bunny ear” telescoping elements from an old TV and try hooking that in.
• You could also make a pair of bow ties that are the correct length for VHF, but they might be unwieldy. I’d play with the telescoping elements first.

The channels specifically mentioned (7 and 12) are in the VHF high band, which is a different range of frequencies than 2 through 6. You need an antenna that is good at picking up 174 Mhz to 210 Mhz (for those two channels).

Question: Is there a TV Frequency table out there?

Answer: This one looks pretty good. Television Frequency Table

When I have some time I’ll look more into the element lengths needed for the VHF channels.