Links to stuff on this blog

Use the Site Index of Projects page link above for an easier way to find stuff on my blog that you might be looking for!

Sunday, November 27, 2011

Homemade Lab Jack (Part 1)

This is a rather ambitious project and by ambitious I mean it might not work. On many occasions I have needed to adjust the height of something, usually a camera, in very fine increments. A tripod works really good for that and I have one... but a lab jack would be much better so I decided to build one. Also a lab jack is a nice thing to have!
There are three industry standard approaches to designing a lab jack. One is THIS where there is a scissor lift that has to slide in a track relative to the platforms. One disadvantage is that it becomes less stable as the height grows. Another design is the Dual Pantograph like THIS that is a bit more stable but requires a lot more linkage's. A much more stable design uses three linkage hinge's in THIS type of configuration. With this one there are two opposing linkages and a third to add stability. This last configuration is what I decided to build.
Homemade Lab Jack

The above picture shows how much progress I have made at this point. Not much! You can see the opposing hinge systems and the location of where the third will be. The wood that I am using is Baltic Birch plywood, the same wood that I used in my clock. There is a 1/4-20 all thread bolt running through the hinges and that was the tricky part of this project.

Sunday, November 20, 2011

Wind Tunnel Smoke Generator

A couple of weeks ago I wrote about the details of my home made wind tunnel and I wanted to add some recent modifications I made to the smoke generator system. The smoke generator that I am using is a Halloween fog generator and I modified it by attaching a hose to the outlet (and rewired it!). There are some details about that in THIS post. I had a problem with that setup because the smoke (or fog if you want to call it that) coming out of the generator was hot and it melted the plastic tubing that I had attached to the generator. Check out the post above that I linked to for details. A second problem was that the smoke was being blasted right through the wind tunnel in bursts. I only had a few seconds to make an observation with smoke! Another problem that I had was the liquid that is used to make the fog was condensing in the tube that I attached to the output and that condensed liquid was filling the tube and creating back pressure. The tube was essentially being blocked by the condensed liquid, getting hot and finally burst. I decided that I wasn't going to run this smoke system any longer without addressing those issues (and cleaning up my garage).
Smoke Generator Accumulator Tank

What I came up with is shown in the picture above. I got a 3 gallon plastic paint bucket and attached a couple of barb fittings to the lid. On one of the barb fittings I ran some 3/8" fuel line hose from the smoke generator and on the other fitting the plastic hose feeds the wind tunnel. You can see the wind tunnel in the lower right corner of the above picture.

Saturday, November 12, 2011

Electric Bike Design

I wrote a post HERE in September about a electric bike that I designed, the E-Moto Monterey Electric Bike. There were a couple of pictures from the Las Vegas Interbike trade show that looked nice but didn't really highlight the unique features that this bike has. Below are some better shots of the finished product and some comparisons to the original CAD design that I did using SolidWorks.
Monterey Electric Bike (real photo!)
Monterey Electric Bike (CAD Model)
You can see some differences if you look really close between the CAD model design and the finished product. In case you can't see the differences I have more closeup pictures below!

Sunday, November 6, 2011

Wind Tunnel Details

I was sick with the flu this week so I didn't get very much done. I really wanted to do some more experiments with the Plasma Actuator that I wrote about a couple of weeks ago HERE but due to the illness and the cold spell we have had recently I stayed out of the garage. Because of several emails that I have received asking about the wind tunnel, I decided to write a little about the wind tunnel that I built and used for those tests. HERE is the original post that I wrote about building the wind tunnel that has most of the construction details. Below is a picture of the results that I got with the tunnel.
Airfoil Plasma Actuator in my Wind Tunnel
In order to see the airflow I added smoke (fog) to the airstream using a Gemmy Fog Machine. HERE is a link to their website for the model that I picked up at WalMart for about $25.00. The Fog Machine heats up and sprays a mist of glycol and water for about 60 seconds into a heating tube and the result is fog. As the mist is sprayed into the heating tube the tube cools down and the machine stops spraying until the tube can heat up again. I didn't like that so I took the Fog Machine apart and modified it so that it produces fog when I press the button and stops when I release the button. It's always fun to take apart brand new stuff!