Friday, January 22, 2010

A little joint-replacement surgery for my Laptop

In hindsight, the display hinges on my Dell D600 laptop have been a little flimsy for awhile. We really noticed a problem a couple weeks ago when one of the hinges was bulging up under the plastic cover. After a closer look and a little research, I determined the hinges were partially broken, and weren't far from totally breaking and letting the screen flop open.

I wasn't too happy that my hinges had broken, but I have to remember it's lasted almost 6 years now without any major issues. As it turns out, this is a fairly common problem, and replacement hinges were easy to find on eBay for less than $10 with free shipping. Since I used to repair laptops in college, I wasn't afraid to open up mine to do the repair myself, and Dell has a nice service manual available online. Overall it wasn't too difficult, just a lot of small screws to keep track of and some rubber bumpers to remove. My new precision screwdriver set came in very handy for the job.

Here's a photo of the damage to the left hinge, broken in two places, as shown next to the new hinge. The right hinge was only broken in one place, but still broken. The new hinges are installed and are working great. I like fixing things :-)

Wednesday, January 20, 2010

Building my magnetic stir plate

Back in November I went out to learn more about brewing beer. Among the demonstrations, one guy showed us a magnetic stirrer he made using a computer fan and a magnet. He was using it to stir up a yeast culture. In theory, this helps the yeast grow and thrive more than just letting them sit. Since starting a healthy yeast culture is an important step in making wine and mead, I thought I could use something like this for myself. Plus, I love a good workbench project.

The principle is very simple: place a magnetic stir bar (a small plastic coated magnet) in a container, and then place a spinning magnet underneath the container. This will spin the stir bar, and thus stir the mixture. I started researching, and ordered some small stir bars. I tried using some salvaged hard drive magnets, but I didn't like the results after my initial testing. After that I bought some smaller stir bars from eBay, and it turns out the seller of those stir bars runs the website stirstarters.com, whom I must give much of the credit for the design and my inspiration. While he sells his own stir plates, he also understands the DIY culture, and provides details about his design including a schematic for the speed control. With this information, I set out to make my own with one major difference: I didn't want to have to keep track of another AC adapter. I just wanted to run AC wall current right into the device for simplicity.

To get power to my stir plate, I would need an AC adapter to convert 120V AC to 12V DC, and it needed to be small enough to fit inside my project. What I found was a wall adapter that converted to a cigarette lighter plug like the one in your car. These are often sold as cell phone accessories, and with some searching I was able to find them very cheap online. I removed the "car plug" and the prongs that go into the wall, and replaced them with wires to connect into my project. This gave me 12 volts DC for powering the stir plate.

To actually get the AC power into the box, I salvaged an AC inlet plug and power cord from an old computer power supply. The plug mounted nicely onto the project box, and looks pretty nice I think. I also used a molex plug and wires to carry the 12 volts DC out of the AC adapter.

The speed control circuit was fairly simple to build, with the exception of the voltage regulator which I put on backwards the first time due to a poor diagram on the package. Thankfully it didn't cause any damage, just a confused engineer. I was able to find all the parts I needed at the local Radio Shack, except for the potentiometer, which had an uncommon resistance value, so I ordered that and the project box from Jameco. Had I not already bought my parts from Radio Shack, I would have gotten everything at Jameco. They have good selection and good prices. I mounted all of it on a proto circuit board to keep things relatively tidy, and added a power indicator LED to the circuit because I had some laying around... and LEDs are just fun.

The stirrer itself is made up of an old computer fan I pulled from an old project, a plumbing adapter from Home Depot which happened to be the perfect height, and some super strong button magnets from Ax-Man Surplus. This whole assembly is held together with epoxy, and thanks to some careful planning and assembly, is pretty well balanced when it spins.

The completed stir plate works quite well. I can just plug it in, turn on the power switch, and adjust the speed. I haven't tried it out yet on a yeast culture, dissolving some bentonite, or anything else yet... but it can stir water like a champ! I tested it out on a 1-gallon jug and got a little vortex, so this looks like it will be a useful tool to have on hand.

Tuesday, January 19, 2010

Happy Birthday to my new Nephew Toby James

Happy Birthday to my new Nephew, Toby James. He was born January 19th, 2010 and weighed 7lbs 11oz. We were able to visit him later that evening. He was very alert and very cute! My sister and her husband and their new son Toby (and big brother Sammy) all seem to be doing well.

Welcome to the family!

Thursday, January 14, 2010

Kitchen Creative: My First Fondant Cake

This past Sunday was our son's baptism, and we needed a cake. Being that I enjoy opportunities to be creative, and enjoy making fancy deserts, I wanted to make & decorate the cake. Years ago, I worked for a joint franchise of Subway and TCBY. When we added the TCBY counter, I wanted to learn a bit about cake decorating since we would be selling custom cakes. He paid for me to take classes at Michael's, which was fun. So... this was a chance to try it again.

As I researched and thought of ideas, I started to read up on Fondant, and found lots of how-to videos online with tips on technique. Fondant is basically a cake frosting with a dough-like consistency. It's typically rolled out flat, and then draped over a cake to give it a smooth texture, and is often used on high-end "3D" sculpted cakes. I found a recipe on AllRecipes.com that seemed simple, so I decided I would give it a try.

I decided to make a two-layer 9 by 13 cake (although in hindsight one layer would have sufficed). I cut some cake off of the top layer and used it to sculpt a small turtle, like the ones his nursery is decorated with. I then used canned frosting to stick everything together, and frosted the outside so the fondant would stick.

I made up a batch of about 3 lbs of fondant. This particular recipe seemed a bit greasy to me due to the use of shortening and corn syrup, so if I try this again I might try another recipe. I did add more powdered sugar to try to compensate though. The hardest part was doing the base of the cake, but perhaps if I had the proper supplies it would have been easier. Rolling out a sheet of fondant big enough to cover a 2-layer 9x13 cake and then transferring it to the cake was tough. A smaller round cake would have been easier to manage, but I was able to do it without too many tears or cracks.

I took the fondant that wasn't used on the cake and colored it with some food coloring gel to make blue and brown for the turtle. This worked rather well. I rolled out small sheets and draped them over the turtle and trimmed off the excess. I like how it turned out.

The final piece was lettering. I had plenty of blue fondant left over, so I rolled out a sheet and used a pizza cutter and knife to cut out lettering for the cake. It was very time consuming but it turned out well. To make sure they stayed in place I used some fondant thinned out with water as a kind of glue. The final result was put out on Sunday and everyone was impressed. Best of all it tasted good. I enjoyed a piece of turtle shell myself :-)