Be Happy

Back in Caracas and back at SAIME trying to solve my visa mess. No progress yet, but made progress on Benjamin's VE passport. Took a few pics this afternoon. My favorite is this one. Saw this statue while riding in a taxi. It is of Gen. Francico Miranda and his base is saying, "Be Happy" and "Infinite Love". Nice message from the generalissimo. 

Be Happy!

My Bamboo Skewer Box Kite

I haven't built anything creative in quite a while. I used to be famous at my school for my creations. I've built all sorts of stuff from everyday, low-cost materials. Probably the most sophisticated thing I've built is my wind tunnel which really works and is very precise.

Wednesday at school we are having our "Spring Fling" and I am on the kite making team, so I worked with the elementary students on making simple kites.

Back in kite mode got me thinking...

Box kites: Then...I remember my brother having a box kite and I always thought it was cool. I first tried to build one from scratch about 30 years ago, but it didn't work out too well.

Now...On the Fausto Trail on El Morro is a frame to an old box kite that somehow ended up there. Who knows how long its been there, but each time I ride past it, I look at it noting its construction. It is very strong for being around as long as it has, so I've tried to duplicate the design using bamboo skewers used for kabobs.

The prototype...
Yesterday I built a box kite from drinking straws just to see if I could. I built it in about 45 minutes and it worked okay until the drinking straws started bending from the gusts of wind. I decided I could use the same dimensions and build one out of sturdier bamboo skewers. Here's how I did it:

1. I cut off the pointy ends of 12 skewers so each stick is 26 cm.

2. To make the long sticks, I overlapped them about 2 cm for a length of about 50 cm. They were glued and lashed together with cotton string.

3. The cross pieces are also 26 cm, so they cross at 13 cm. I made a little notch at 13 cm then glued and lashed them together with the cotton string, and lathered on more white glue.

4. The long sticks were notched at 6.5 cm from each end and the crossed pieces were glued onto the long pieces. The glue was allow to dry, then reinforced with a paper/white glue gussets.

5. The cross pieces make little triangle with legs each 13 cm long. The string which wraps around the frame for stiffness and strength creates a hypotenuse of 18.5 cm on each side. The perimeter around the frame is about 74 cm. The string should be cut at 1 m in length so you can tie it off.

6. The perimeter coincidentally was the was right sized for the little grocery bag I was using without having to cut and retape together. The width of the plastic is 13 cm. I just slipped the plastic over the frame for a snug fit. I used stick glue to glue the plastic on to the frame and string guys. I just eyeballed the width and it seemed right.

7. The bridal is about 75 cm in length tied to two corners; one top, one bottom.

Total weight is probably about 25 grams. I need to confirm that tomorrow.

Anyway...it flys!

Brahma Power

Daniel and I were commuting back to El Tigre on Sunday afternoon when we came upon this ranch truck. I liked the Brahma bull on the rear panel. Had to grab the camera! Click on the pic to get a closer look.

Carrying the Fire

I was checking out my friend Vulture's (a.k.a. Eurotrash Wade...at least what I call him) blogsite which had a link which led me to his flickr.com site. Like the Nathan pic, I really like this pic as well. This is a great father/son pic. Keenan is brazing up his bicycle in Wade's Vulture Cycles shop while his dad, Yod, is looking on. I first knew Yod from several years back when he was part of the famous Team Mutant in Flagstaff, Arizona. I was at Yod's wedding in Oak Creek (a few miles N of Sedona). Keenan was born and it appears that he has now grown into a fledgling Mutant rider himself. Its great seeing the positive influence of a father on his son. Great pic!

photo credit: Vulture Cycles

My Wind Tunnel (updated)

Science Fair is on Friday. My students are frantically finishing up their projects. Most of my science plans have been put on hold until next week.

I have a 7th grade student who is really interested in airplanes and flight. This gives me an opportunity to dust off my classroom wind tunnel and let this particular student gather some data on various wing designs for his science fair project.

I built my first classroom wind tunnel in 2003, the 100th anniversary of the Wright brother's flight at Kitty Hawk. A travel version model of the first generation wind tunnel was presented at the 2005 NSTA national convention in Dallas, TX. It was there I met Bill Nye, the Science Guy, and I was able to give him a private presentation of some of my projects. He liked what he saw. He liked the idea and the design. He encouraged me to build a second generation.

This wind tunnel was built around late 2005 or 2006 by me and one of my high school students. This second generation wind tunnel has a couple neat features like the external lever system and separate test chamber. The main body and test chamber is made from sheets of polystyrene, but unlike the first tunnel, the suspension system, as mentioned above, is external and made from balsa wood. The models inside are attached to the suspension via PVC plastic drinking straws.

It works pretty good but of course there is always room for improvement. Right now it only measures lift, and I still want to build a system to measure the drag force on the model. I've made prototype models of a drag system that I think will work pretty well, but just need to get around making it from balsa.

Some day I'll get around to making a 3rd generation.