Friday, November 8, 2019

First Log Round Complete

The first round of logs for the cabin are in. For an added touch I cut a blind dovetail for the joints of the side logs to the front and back logs. This will provide a mechanical connection at these corners, although unnecessary, I think it will enhance the cabin.

First item of business was to layout and cut the socket for the dovetail. Using the framing square blade width (2") and tongue (1.5") for distance units. The dovetail female socket was 4" x 2"  and 3" long and 3" deep. This was cut and chipped out and then the mating dovetail cut to fit.

One down and three to go... The true test will be in the fit. Care was taken to chamfer the edges of the mating dovetail as the last thing I wanted to do was have to struggle with these if they hang up when assembled.

Well that worked out better than I planned!

 Now with the first round of logs cut and joined it is on to Round 2. Sizing the logs and then cutting the half dovetail joints so that the chinking joint is between 1.5" and 2" will be the next challenge.
So far so good.

Thursday, October 24, 2019

Beginnings of a log cabin

A 2x6 treated bottom plate has been layed out and leveled up. This will be the footprint for the 12 by 16 log cabin.

The first round of logs will sit directly on the bottom plate so these logs must be hewed flat on three sides. We're making timbers now!

The door frame has been located and secured in place. There are a number of good reasons for this. In building a log cabin having a door opening is a handy thing to have as it allows easy access to the inside of the cabin during construction. Otherwise you will need to climb over the logs with a ladder and this will become a real pain as the walls get higher. Also because I have a limited number of logs I will be framing in the windows as I go to save logs. The corner joints will support the logs but the ends where the log meets the door or window frame need support. You could just peg through the door frame into the log end but that would not allow for movement as the logs shrink in diameter. So I cut a 2" wide 2- 1/4" deep dado groove in the door posts. The end of each logs will have a 2" by 2" tongue cut into it. This tongue and groove joint will make the wall stable and allow for movement as the logs shrink and the wall height lowers. After the logs have dried then the ends will be pegged and chinking can be done.

Now if you have been following the construction you realize that doing this the "old school way" there is a lot more to the processes than most people think. Many problems to solve along the way. One of these being after you select the log you want out of the rack how do you get it out to work on?
Handyman, planks, blocking and a couple of can't hooks will do the trick.

And now it is ready to peal, layout and hew. Snap!
Now it is on to cutting and joining the first round of logs for the perimeter.

Saturday, October 12, 2019

Cabin #6 Planning

After having built 6 other small log cabins of various designs and joints. I decided to build a 12 by 16 half dovetail joint cabin and hewing the logs for it myself. And after completing the proof of concept that I could handle the hewing I drew up the cabin and made a model to see how it would look. Unique to this one will be the double front doors. As well as a half loft above with stairs.

The windows and doors will be framed with 6 x 6's. The side rails will have a 2" dado groove cut into  them to receive and hold the tongue that will be cut into the end of the logs. This will allow movement as the logs dry and settle. Height to the ceiling will be about 7 feet. Loft floor to ceiling peak will be about 6' - 6". Porch posts, rafters and floor joists will be made out of 6x6's.

The stairs to the loft will run against the wall and the loft will be open to about half of the cabin. Double windows on each end in the gables will allow for plenty of light. Roof boards will be covered with 2" of styrofoam insulation topped with a steel roof.

To try to get  a handle on how much the walls will shrink I cut a 2" thick slice from one of the green logs. I have measured and marked the diameter at three locations. The disc weighs 14.6 pounds green. I placed the slice in my house to dry out and shrink. This should happen over the next month or two and give me some idea as to how much the logs will shrink so I can better cut the vertical window and door post heights. Vertical posts for the porch will have screw adjusters drilled into the bottoms.

So here is the 2x6 treated bottom plate, squared and leveled. to build on. The finished cabin will be disassembled, transported to its new home and reassembled on a floating concrete slab. This winter I will be able to look out at the cabin building progress as I go inside to warm up and have a nice lunch or coffee :-)

Now it is back to work on those pesky half dovetails and figuring out the different depth cuts to make so as to maintain a 1" to 2" gap for chinking while keeping the walls level and plumb.

Saturday, September 28, 2019

What do you "See" ? Log Cabin #6?

So What would you say if someone asked you if you wanted 20+ pine trees?

If you are reading this you just might say yes! Also, if you are reading this, I am guessing that you are one of few individuals that can "see" the cabin in these logs. You can relate to and appreciate what pioneers did with these logs and what it took to transform them into shelter.

I said yes! Sure I'll take them. Come along for the next year or so, taking the path less traveled as I transform these fine logs into a log cabin just like the early pioneers did. One log at a time.

Sept. 26, 2019

After the logs were dropped off on my land they needed to be racked so they were up off the ground and could be looked over, selected and individually worked up. There are about 40 logs. I numbered them and did some rough calculations. Looks like about 600 linear feet of log. Building walls with no windows would make a 14 by 16 cabin ten logs high. Building walls with a door/s and windows cut in would allow for a larger cabin. Something to consider.

Although I have built 5 log cabins before I wanted to do a "proof of concept" to see if I was up to the task as the birthdays are piling up on me. So the first step was to peal a log (as seen in the top picture). This went well and only took one Alive and and about an hour.

Since I am going to make half dovetail notches for the cabin corners the logs will need to be hewn flat on two sides. Most logs will be hewn to a 6 inch thickness. To do this first lines need to be laid out and cuts made to depth so that the wood can be chipped off both sides using a broad ax.

Looking at log cabins that were built 150 years ago I am always in awe at the amount of work that goes into hewing logs like this.

The next step is to turn the log and work the sides down to the line with a smaller hand axe. Takes about an hour to an hour and a half to do a log like this.

Sure all this could be accomplished by taking the logs to a sawmill but, then I would not "see" what I am going to learn over the next year as I walk along, "the path less taken."

Tuesday, May 14, 2019

Active YAW 2.0 KidWind Challenge

Last week I posted my first design of a KidWind turbine YAW using a tail to achieve upwind passive yaw modified to make it a motor driven Active up wind YAW like the commercial grade units.

To the left is my improved 2.0 design. To the right you can see that the YAW with a tail required the tail to be attached to the 1 - 1/4" PVC pipe that rotated around the center 1" PVC pipe that the nacelle was attached to in last weeks post.

The key is this. Mounting the 32 tooth KidWind ring gear to a 1 - 1/4" center post and fixing it to the top of the pipe (turbine tower in the real world). This is trickier than it looks. Getting the pieces  concentric and getting enough thickness to hold threads for the set screws.

And the whole package (Nacelle in the real world) sits right on top of the tower just like this. Looks like a nice opportunity to bring in a new technology, fiberglass, and the design and construction of a shell to cover all this and protect it from the weather and birds! Maybe even some sponsor advertising!

So the top is pretty much the same with the limit switches and control vane that senses the direction of the wind. But, attached to the bottom side of this board are the relays and battery to power the system (seen in the picture above this one).

Another key to the design is that the plate that holds the drive motors is fastened to the 1" PVC that goes down inside the 1 -1/4" pipe (tower). The plate sits on and rotates on a thrust needle bearing. When the signal comes from the wind vane the motors turn the pinion gears either CW or CCW to turn the Nacelle and blades to point into the wind. Two motors also act as a brake when not powered.

As a bonus I put a piece of elastic on the bottom back to hold the Vernier GO Direct Energy Sensor and my 25 watt 30 ohm resistor is mounted also so it can be attached during a wind tunnel test.

So if the technology that runs your cars power windows can be adopted to the way wind turbines YAW to face the wind. And a KidWind team can work to design, build and solve all the problems that  present themselves during the process. I say KidWind is a great hands on learning that covers all the S.T.E.M. bases and more!

Thursday, May 9, 2019

To YAW or Not To YAW? That is the question.

Added to the 2019 National KidWind Challenge this year is a YAW component challenge. Turbines will be placed in the wind tunnel on a turntable. After the blades get up to speed the turntable will be rotated 90 degrees. This will simulate a "real world" change in wind direction experienced by all real wind turbines. To adjust to this "change" in wind direction the turbine will need to YAW (rotate) to keep the blades facing into the direction that the wind is coming from to keep them rotating and maintain energy output.

Sounds easy, right? Lets see...

There  are basically 3 different ways wind turbine are constructed to accomplish YAW. Two are passive (relatively simple) and one is active (very complex). There are pros and cons to each method and that gives KidWind teams something to think about and consider.

The first passive system is one that most people have seen and is the type used on old farm water pumping wind mills. They operate with a tail that is behind the tower and blades. The blades operate UP Wind of the tower and Nacelle. The tail acts like a weather vane and keeps the blades facing  directly into the wind if it is the correct size and shape.

The problem is to engineer the attachment of this tail so that it can rotate the Nacelle that holds the blades, gears and generator. Good problems to solve and many options to choose from.

The second passive system is the Off Set Pivot. The blades operate DOWN Wind of the tower and Nacelle. In this system the wind force on the blades causes the Off Set to Pivot and rotate so the blades are facing against the wind direction (down wind of the tower). Some wind force is blocked due to the tower and Nacelle getting in the way. This is referred to as tower shadow. No tail or system to mount the tail is needed. However some weight balancing needs to be done to reduce the load of the blades and Nacelle that will be placed on the Pivot bearing.

Lastly in this discussion is the Active - Motor Driven system. All utility grade wind turbines use a system like this. It is very complex, expensive and good at providing YAW for maximum energy output. This requires two sub-systems. One that can determine the direction the wind is coming from.  And another sub-system that can rotate the Nacelle and Blades (this is a VERY BIG job) and automatic communications between the two systems.

In my model, as a proof of concept I used the existing technology the runs your electric windows in your vehicle. At the bottom of the picture you have a wind vane between two micro switches. This determines which way the wind is coming from. If the wind is coming straight on the vane is in the middle and no switch is on. In the top part of the picture you have a large gear that can be rotated CW or CCW by the small gears driven by the three small DC motors when they receive a signal ( polarity + or - ) ( polarity - or + ) from the micro switches if pushed to the left of right (up or down in this picture) by the wind.

I will let the circuit drawing do the talking here on how it is wired to reverse the polarity and thus reverse the direction the motors turning the large yellow gear CW or CCW.

In my model I applied the Proof of Concept by fixing a ring gear to the stationary part of the tower mounted to the tower base. The green gear is glued to the white PVC and then set screwed to the 1" black pipe.

The wind direct "signal devise" (wind vane with two micro switches) is mounted to the top of the Nacelle behind the blades.

The circuitry, relays, battery and drive motors are mounted to a plate that is locked to the main
1 - 1/4" PVC pipe that slides over the 1" Black Pipe than the green gear is set screwed to so it cannot rotate. The 1 - 1/4" PVC rides on a thrust bearing and allows it to rotate. The small green gear on the left in the picture turns when it get a signal from the micro switch. Since the large green gear is fixed (set screwed) the motor and plate it is attached to rotates the 1 - 1/4" PVC, Nacelle and blades to keep the blades pointed facing the wind. YAW!

Everything you see here from the wooden plat up rotates around the green gear that is set screwed to the the 1" pipe screwed into the base.

Active YAW system model. It will be interesting to see what the different KidWind Teams come up with to solve this years YAW Challenge problem.  Plenty of good stuff to learn and apply. YAW'al!

Saturday, April 27, 2019

Safety, Tower Climbing and KidWind

What do Safety, Tower Climbing and KidWind all have in common? Well if you are on a KidWind Team at Darlington Middle School you learn a lot about the design, building and testing of model wind turbines to produce electricity. Then if the you are lucky you get to see and learn about climbing wind turbine towers, the equipment used and the attention to safety that everyone in the industry must consider and maintain. SAFETY is number one!

I learned about ENSA ( a Division of Mallory Safety and Supply) located in Mukwonago, WI at last years National Kid Wind Challenge in Chicago. There I met, director of operations,  Valerie Marquis and we talked about the KidWind program and what the kids were learning. Since safety in the wind power industry is their business I thought this would be a great opportunity to expand the learning for the KidWind Teams so we set up a demonstration/presentation in Darlington on my wind turbine tower next to the school.

I cannot say enough about the ENSA people and the work they did with the Darlington Middle School KidWind teams this past Friday, April 26, 2019 but I am going to try.

The weather was great! April Vollm and Rob Siegel from ENSA arrived early to look the tower over and rig the lines that they would use for the climbing demonstration and rescue of an injured climber from the tower. Students were told that this type of training is required by OSHA every two years, from people like April and Rob, for wind turbine climbers to be certified to work.

April met in Roger Zee's tech ed room (Roger is one of the three KidWind Team coaches in Darlington) with the KidWind Teams and some of Roger's students. The KidWind teams showed April the wind turbines they built to win the 2019 Wisconsin KidWind Challenge in Madison and have been improving (adding a yaw system) to compete in the National KidWind Challenge on May 21-23, 2019 in Huston, TX. April explained some of the work she does and how important SAFETY is to everyone. Especially in the wind energy industry.

From the classroom it was over to the workshop at my home and some "show and tell" about the equipment, how it works and how it is used. April is a natural at this, keeping the students engaged and encouraging them to ask questions and learn more about what they were hearing and seeing.

One of the main pieces of equipment April showed the students was the 50:1 ratio winch that she would be using to rescue Rob (playing the injured climber) in the demonstration. The girls could easily relate to the ratio as the wind turbines they built have a 1:32 ration gear train to drive their generators.

I cannot help but to imagine that some of the girls knowing the make-up of the gears for their 1:32 ratio and how they are assembled thinking how the 50:1 ratio and what type of gears are used in this piece of equipment. The design? The engineering? The application of something they learned in KidWind. Priceless!

It was time to get out and see all this equipment and training put to work, up close and personal. Rob and his helper had rigged the lines on the tower. After a "Buddy Check" (climbers always work in pairs) Rob climbed up the tower and prepared himself to be rescued. April continued to engage the students using the same terminology she does with actual turbine technicians training in the field (Buddy Check, PFP, Self Evacuation Kit, Limited Fall Arrest, Anchor Points, Helmet Ratings E and C, Connecting Devices and Cows Tail just to mention a few).

Now for more good stuff. The climb. April in the green helmet has climbed up the tower after assessing the situation, calling the rescue people and determined the course of action needed. She has placed herself above Rob and determined that he needs to be lowered safely down from where he is to the ground and waiting emergency personnel. Rob easily out weighs April by 100 pounds. She attaches the winch to the tower above Rob and make the necessary attachments.

After making the connections Rob is being lowered down safely to the ground for a successful rescue and treatment by EMT's. If this was an actual rescue in a wind turbine tower all the equipment and rigging would be left "as is" in the tower for the accident investigation crew. This is done for several reasons but one of the main reasons is to learn from the accident and make any necessary corrections to equipment or procedures to prevent it from ever happening again in the future. SAFETY really is number one in the wind energy industry.

And THANKS to ENSA and people like Rob and April these Darlington Middle School  KidWind Team members get it! They know, just like the people that run and service the Quilt Block wind farm that EDP Renewables operates in Darlington, WI.    SAFETY IS NUMBER ONE!

Join a KidWind Team and have some "serious fun" today!
Dick Anderson.  KidWind Advisor.  Darlington, WI  53530