All Aboard!

Sat, 1 Mar 2008 14:44:17 -0600

Another project has begun at the Rusty Nail Workshop. Older Son and Younger Son want to help build a model railroad. We are thinking of HO scale, which gives a realistic train setup without using too much space. We don’t have much to start with, other than an idea to use a 4’ x 8’ sheet of plywood.

We spent some time sketching out track layouts. Mine looks like an oval with a few extra lines. I figure I can spend more time on the scenery than the actual track. It includes an iron ore mine, a city, a mountain, a beach, and even a lighthouse. Tying all of these items together in a realistic layout will be difficult.

Of course, Older Son decided he had to have his own layout. His is much more detailed than mine, but then again, he is 8 years old. If his building skills are anything like his drawing skills, we will be fine.

As usual, we will take any advice from our readers. You can write to us at:

A Doll’s House

Tue, 25 Dec 2007 12:48:10 -0600

About a year ago, I realized my daughter would need to have a doll house when she turned four. She doesn’t know she needs one, but I do. While on a vacation in Duluth, Minnesota, I happened to come across a small store called Teeny Weeny Miniature Cottage in Canal Park. The owner was nice, and offered numerous tips on building a doll house. She eventually recommended a kit, and I purchased the Bellingham Farm doll house (BL 455) which is no longer being offered.

The doll house is described this way: This beautiful, large farm house kit is the perfect doll house for anyone with an eye for authentic styling. The wrap around porch is just like the real thing. An ox-eye window is characteristic of early American architecture. There is a beautiful fireplace mantle with ornate detail to recall the style of grandma's house. Comes with working windows and doors, brickwork, stairs, rails, porch posts and shingles. It has 3 stories, 8 rooms, and 1 staircase. It is made from 3/8" MDF board.

The doll house came with very detailed (and funny) instructions. They walk you through the construction, step by step. I now have the walls assembled, part of the roof, and the flooring. The house stands fairly tall, about three feet high. It gets heavy after adding the walls and the roof. The 3/8” MDF is nice to work with, but there are some signs of a dull cutting blade when the doors and windows were stamped out. Nothing a little wood filler can’t fix.

Well, the wood filler worked with mixed results. The filler does not work well around door and window cutouts, but works well to smooth over damaged siding. I’m hoping the window and door trim will cover the bad stamp cutting done at the factory.

When trying to find a color scheme, I came across the Sherwin-Williams house color selector web site. This site allows you to select a house that approximates the house you will be painting, and then test color samples to see how they would work. The test house I used to select a color is shown on the right. It’s called the Victorian 1 on their web site. I chose a Plum Brown color for the main house color, white for the trip work, and a color called Beguiling Mauve for the house accents. It should look something like the sample house on the right.

I picked up the paint, and started to paint the real dollhouse this weekend. It looks like the main part of the house will need two coats of paint. The first coat soaked into the wood pretty well, and some of the wood color can be seen through the thin areas of paint.

I’ll start on the porch and railings while the main house color dries. Now I’m off to the store to pick up a few more tools.

I’ll update this project as I continue to build this house. Please be patient, it may take me a few years, although I must be finished by the time my daughter turns four.

Remote Temperature Sensor & Energy Monitor

Thu, 11 Oct 2007 20:42:46 -0500

Like any good project, this one started with a need. I have a home which has a radiant floor heating system. I’ve never had a heating system of this type, and as such, I tried to learn everything possible about the system. My only concern was the operation of the system when I wasn’t at home. Clearly I needed a way to monitor the performance of the system without actually being on site.

My first attempt started with a couple of temperature sensors located in a few rooms to monitor room temps. Here’s where the problem suddenly became difficult. Because I try to minimize energy consumption, I wanted a way to operate the temperature sensors without a computer running 24/7. Even with the most efficient computer, I’m still out $2,000 for the computer, plus the continuous cost of 10+ watts of power. One example of a computer that can run under 10 watts is a Sony Vaio UX-390, but this is certainly not a web server. I thought I could use an existing 802.11-g network in my house, and send the temperature data directly from the sensor to a remote computer. Unfortunately, the only thing even remotely close to this was a temperature sensor from G2 Microsystems or Point Six. Both are in the hundreds of dollars of cost per sensor! Ouch. I tried searching the internet numerous times for ethernet based temperature sensors, wireless temperature sensors, and even home monitoring temperature sensors - all without any luck. Clearly I needed something else.

Further research led me to a web site named Our Cool House. Phil, the owner of this site, has designed and built a device called a Web Energy Logger (WEL). This device, which includes its own built-in web server (albeit not wireless - yet), costs about $350 and can monitor tens, if not over a hundred, sensors. They can be temperature sensors, current sensors, and many others. Although the device is a little expensive, it is apparent that Phil has put a lot of time into the design and software used by this device. It functions both as a web server as well as a data logging device (but the data is stored at www.welserver.com. The device uses a communication bus called 1-wire, which was original developed by Dallas Semiconductor for low-speed data signaling and power of a single wire. The 1-wire name is a misnomer, the sensors actually use two wires, but only one wire carries the data and power for each sensor, the other wire is ground.

First, I needed to design my 1-wire network for the WEL to monitor. I started by creating a list of locations where I wanted to monitor the temperature. My list looked a little like the following:

Heat (Air) Exchanger
Fresh Air In
Stale Air In
Stale Air Out
Fresh Air Out

Water Heater
House Hot Water
House Cold Water
Radiant Floor Heater Water

Room Temperature
Master Bedroom
Living Room
Kitchen
Bedroom #1
Bedroom #2
Family Room

Miscellaneous Temperature
Outside
Attic
Floor Slab
Garage

I purchased 18 temperature sensors (DS18B20-PAR) and I plan to solder them up myself. Although they have three leads, only two of them will be used. I also purchased several current sensors to monitor whether a motor or heater is running. I plan to use my home’s existing telephone wiring, which all comes to a connection point in my garage. I’ll disconnect the couple of circuits I’m actually using for phones, and the rest of the wiring will then become a central hub for my 1-wire network.

My favorite part about the WEL device is the ability to overlay my temperature sensor readings on top of an image that I supply. I immediately thought of Google’s SketchUp software, which is free. This allowed me to create a three dimensional view of my house. I will overlay my sensor readings on top of this image with the tools provided on the WEL site.

All 18 of the temperature sensors arrived and I started to construct my sensor network. After installing about three temperature sensors, I wished I had opted for the pre-soldered sensors from www.welserver.com. This would have saved a considerable amount of time and frustration attempting to solder tiny connections, while making sure everything had enough heat shrink tubing over them to prevent short circuits.

I tried to wire everything in a star configuration (one main twisted pair cable with multiple lines running outward from one central point), which was recommended when I purchased the WEL device. Some sensors didn’t work well in this configuration, so there are a few branches on the main leg of my star network.

I connected to my router tonight, and began testing and updating individual sensors. Oddly enough, everything seems to be working. No need to configure the WEL IP address or any other network configuration! The sensors came online one at a time, just after I plugged them in. Temperature data and run-time data began flowing immediately. I couldn’t have asked for a better installation.

I went to the WEL web site, and began to specify how I wanted my log file to look, and how I wanted my data displayed on my personal image (see house layout above). I have some serious configuration to do here, but once I place everything, it should be fairly permanent.

I fully expect to add more sensors in the future, now that I’m getting some good data. This really surpassed my expectations! Installation was a breeze, especially since I used the yellow/black wires from my already-installed telephone jacks. The red/green wires supply my phone server, and neither is interrupted by the other. I have to give this project a 10 out of a possible 10 point scale. Way to go Phil, this is a great device! It is obvious a lot of time and effort went into this product.

Update: My device has been working well now for several months. I have found a couple of issues that Phil has been working hard to fix. First, if you live in a very cold climate, like Minnesota, you will have scaling problems on the graphs when it gets down to -15 degrees or below. Second, it appears that the longest history recorded is only about 12.5 weeks. Thus, if you plan to record temperatures over a year, you may have to keep the data yourself.

The WEL server web site now has location information for the WEL devices installed world-wide. It is kind of fun to see everyone who has purchased these and how they have put them to work. Check our ours in northern Minnesota. Phil has also graciously added an alert function, to indicate things like a low temperature alarm. Only one alarm is allowed, but hopefully he will increase this in the future.

Overall, the problems are minor ones and the pluses are major - I’m still very impressed. You can’t find a better internet based temperature monitor for your money. This one just works.