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Monthly Archives: December 2015
Shoot Boards for Handheld and Table Saws
I live in a small home, and I have to do my woodworking in the garage. Since I have two cars that "live" in the garage, I do not have sufficient room for a full-size table saw (Figure 1).
The biggest challenges I face have to do with cutting large sheets of plywood (4' x 8'). Without the space for a table saw, I had to begin looking for alternative approaches that I could setup and teardown in my garage. Continue reading
Posted in Construction Comments Off on Shoot Boards for Handheld and Table Saws
Output Voltage Control Circuit Design
While I am in management, I still get an occasional circuit design question – I really like these questions because the get me away from some of the monotonous aspects of management (i.e. budgeting). This morning a power supply designer stopped by and wanted to discuss an issue he was having with fixing an issue with an old design. I immediately dropped my budgeting activity and leaped into action. Continue reading
Posted in Electronics Comments Off on Output Voltage Control Circuit Design
After a discussion on the annual time shift of the winter solstice, our lunch time topic changed to the topic of tides. During this discussion, I mentioned that tides have a period of about 12 hours and 25 minutes (Figure 1). I will show you how to compute this period in this post. Continue reading
Posted in Astronomy Comments Off on Tidal Timing
A Little Solstice Math
We just went through the winter solstice of 2015, which in Minnesota is a subject of celebration. This means that we will now start to see more daylight.
The time of the winter solstice varies each year. It occurs on either 21-Dec or 22-December. One of the engineers in my group asked how the time of the winter solstice moves year-over-year. My response was that it moves forward ~six hours each year until a leap year happens, which resets the cycle. Continue reading
Stairway Rise Angles
Quote of the Day History is a tool used by politicians to justify their intentions. — Ted Koppel I was reading this month's Journal of Light Construction (JLC) when I saw an article on building safe stairways per the International … Continue reading
Posted in Construction 2 Comments
Incorrectly Computed Discount Followed By Markup
A few years ago, I hired a tile installer to tile a bathroom I was remodeling. He was a talkative guy, and he casually mentioned that he had chosen not to make any money on his material – he would make his money on labor alone. He said that most of the tile shops he works with give him a 15% discount on material, which he passes on to his customers. Other contractors markup their material charge by 15% to bring the cost back to retail price – this statement bothered me because the markup should be larger than the discount. The math did not seem right to me at the time, but I did not raise any questions because I wanted my bathroom done. I did not think much about this math error at the time until I saw an article in the Journal of Light Construction (JLC) telling contractors that this is a math error that is costing them money. As I read the article, I realized that this is exactly the same error I heard my tile contractor make. Continue reading
Posted in Construction, Financial Comments Off on Incorrectly Computed Discount Followed By Markup
Building an MST3K Tom Servo Replica
In this post, I will provide some photographs I took during our Tom Servo build effort. These photographs do not constitute detailed instructions on how to build the unit, but you will see the general idea. Continue reading
Posted in Humor Comments Off on Building an MST3K Tom Servo Replica
Selecting a Thermal Magnetic Circuit Breaker
I have an application that requires a thermal magnetic circuit breaker that will provide a given level of protection at an elevated temperature. Most thermal magnetic circuit breakers have a current rating that is specific to a stated temperature, usually room temperature (~23 °C). In my case, I need a circuit breaker with a 15 A break current at 50 °C Continue reading
Posted in Electronics Comments Off on Selecting a Thermal Magnetic Circuit Breaker
Those Thrifty German Immigrants ... Combine Repurposed as a Gravedigger
I am the son and grandson of German farmers. Their farms were almost magical to me because of all the belts and pulleys used to drive everything – it would have been an OSHA nightmare. I was always impressed with the self-sufficiency of these farms. For example, the Biegert farm in Hanover, Minnesota had a small sawmill that was powered using a tractor's PTO. Many farm buildings in that small community were built using wood from local trees cut by that mill. In fact, my family still has an affection for woodworking using butternut because that was a wood our father often milled on the farm Continue reading
Posted in History of Science and Technology, Humor Comments Off on Those Thrifty German Immigrants ... Combine Repurposed as a Gravedigger
Yet More Gift Wrapping
My sister and I talk about these practical math problems all the time. Here is another good video that covers gift wrapping with a mathematical slant. Continue reading
Posted in General Mathematics Comments Off on Yet More Gift Wrapping