Zip Line Challenge

My spousal unit, who actually writes this blog, is an author and illustrator of books for kids. She ran across this website for aspiring engineers, and thought it would be interesting to some of my readers. DiscoverE (formerly the National Engineers Week Foundation) helps to unite, mobilize, and support engineering and technology volunteer communities. They hope to increase the collaborative footprint in K-12 education and celebrate with the public as it discovers the value of engineering education and careers.

zipline

I was especially intrigued by their Zip Line Challenge for kids. It’s actually a model that challenges kids to transport a ping-pong ball down a zip line from start to finish in 4 seconds or less. The activity discusses many of the considerations when designing and building a zip line. I’ve uploaded the PDF so you can download it from here, or you can get it from the website listed above. There are a lot of other creative engineering related activities there, all free to download and use in your classroom, home, summer camp, whatever.

Check it out: zip-line-challenge_091316

One of these years I hope to finish my zip line. All is ready, but now the brush has grown up so much I have to hire a tree climber to clear the 420 foot long pathway.

ZipLanding

View from the zip line tower to the landing 420 feet down the hill.

Thanks for stopping by! Be sure to check out our bridge book if you’re thinking about a DIY suspension bridge. Here is the link: Building a Small Cable Suspension Bridge with the Cable Locking System.

And if you’re curious about Robin Koontz’s books, look her up on Amazon as well: Books by Robin Koontz

Images, diagrams, and text copyright 2013-2017 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Habitat for Pond Turtles: Turtle Sofas!

There’s a stream that runs through our property and into Wildcat Creek, close to where our bridge resides. Though the stream is officially nameless, we’ve always called it Phillips Creek, because it ran through the Phillip’s place; Belle’s Creek, because our neighbor’s dog loved to play in it; and Penn Creek, so named by the ODFW who showed up (without notice) to count fish one day. Whatever the name, the stream tended to cause flooding in the pasture in winter, so we put in a pond. How that was done is a blog for another day.

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At first the pond dried out in summer, but once the beavers noticed it, they routed more of Phillips Creek so that it flowed into the pond year-round. We installed a bigger culvert along with a fence to keep the beavers from clogging it up, and had ourselves a nice pond we called Buddy’s Lake, after our beloved Swamp Puppy, Buddy.

We had seen pond turtles in various wetland areas on our property, but were amazed at how fast they discovered Buddy’s Lake. They first appeared on a log that we’d left out, sunning themselves in the spring chill. When that log began to sink, as logs are often prone to do, we decide to make turtle sofas.

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Previously we milled up a few logs for various projects and had kept the sides for benches or whatever. So why not a turtle sofa? And to keep our sofas from sinking, we screwed on strips of rigid insulation we also had left over after building our house. The material isn’t toxic for the watershed.

turtlesofa11After launching the first sofa, we noticed that it tended to hang out close to the shore where a turtle might feel vulnerable to land animals, especially the two-legged variety.

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This turtle is game to try anything new!

So we tied an anchor to a rope attached to the sofa and tossed it out so the log would float more in the middle. We also roped the sofa to a tree on shore so we could haul it back in if need be. And, we added measuring sticks as a fun way to see how big the turtles were. A full grown pond turtle gets to be 6-7 inches long.

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Jeep, Buddy’s predecessor, wonders why we threw such a big stick for him to fetch.

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We added windjammers to a couple of sofas to help stabilize them. Probably not necessary unless you have beavers who like to knock them over and use for their dam.

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This is a turtle favorite, probably because of the moss that has grown on it. Without the foam underneath, this old log would have sunk by now.

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Six is not a crowd!

We’ve seen up to nine pond turtles at once on Buddy’s Lake. We’re happy that our turtle sofas are a preferred place for them to hang out. Or do whatever it is turtles do.

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Floating Mantel Shelf

cherry treesOur house has posts, beams, and siding made from Douglas fir milled on our property. I decided to employ another kind of wood for a fireplace mantel. Bitter cherry, also called Oregon cherry (Prunus emarginata) is a native tree that popped up in our woods when it was replanted in 1988. I wondered what the grain and color would look like when it was milled. It has an interesting bark, that much I knew.

So I picked a tree I liked and thinned the woods by one cherry tree. I parked it in the barn to dry for about five months, then had it milled to about a five foot 5-1/2″x7″ with bark edge on the 7″ width. mantle-sawmill

As control against splitting, I scored slices on one side in varying depths, the deepest being the middle cut over the tree center at about 1-1/2″ deep. Then I primed the sawn sides and left it to dry, standing up, for about 3 more months.

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I was hoping to preserve the bark, so cutting and fitting the corners was tricky. I sanded down the precautionary slices (which were on the bottom) and cut the pieces. I sanded, splined and glued it all together, then applied a clear finish. The bark is threatening to peel, but underneath looks pretty cool so I really don’t care.

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de-barked Oregon cherry

I used a bracket system to install the 35+ pound mantel. I hollowed out two slot holes at 9/16″ depth on the backside that corresponded with metal brackets that screwed to the wall studs.
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Metal straps, which were recessed so that the mantel would fit flush with the wall, were screwed across the hole slots. Taping their location on the mantel top,  I could line them up with the marked brackets.

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A bit of hammering with someone else holding on, and the mantel was up.

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I have 3″ metal posts that I had intended to install on either side, not for support just for looks, but for now we’re seeing if we like just having a floating mantel. Eventually there will be a wall sculpture underneath. I’m just waiting for my spousal unit to come up with something…
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Thanks for stopping by! Be sure to check out our bridge book if you’re thinking about a DIY suspension bridge. Here is the link: Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2016 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

Metal and Wood Computer Desk – DIY

Marvin-DeskLegsI’m not crazy about much of anything we can buy in today’s furniture market, at least in my price range. It’s all badly designed and sloppily made using cheap materials, including a lot of plastic. I feel that even a practical piece of furniture such as a computer desk can be well designed and interesting to look at. And it’s not all that difficult or expensive to make it yourself.

I bought a length of 1-1/2″ square metal tubing (wall thickness roughly 1/16″) and enough steel angle to build a nice, sturdy structure that could hold up a heavy wooden top. I cut and bent the angle steel so that it formed a three-sided structure, allowing for a chair to fit underneath.
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I made wooden feet from some ipe (that’s a hardwood) that I had. I cut out blocks, then cut a little off each of the four sides of each block so that they fit snugly inside the metal tubing, leaving about 1/2″ for a foot. A nice look and a way to protect the floor.

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For the top, I had several 2″ thick slabs of rough-sawn wood that I got from a local sawmill last summer. I knew the seller well and got a great price on some beautiful big leaf maple as well as Lebanon cedar he’d cut down in someone’s yard. The slabs had been drying for about ten months and looked good. I decided to use the cedar for this project.

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The tricky part was picking out the part of the cedar I wanted to use for the table. It wouldn’t be deep enough so a second piece would have to be glued to the first and they’d want to match or at least, go well together.

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finishtable-2A lot of cutting and sanding later, I had pieces that worked. I splined and glued the pieces, removed the bark, then finished with clear Sitkens stain, one of my favorite finish products. I also added holes for the computer cords, etc.

finishtable

I added more angle steel to hold a shelf for the keyboard, and my new computer desk was ready to use.

MarvinOfficeYou won’t find this at Ikea, or anywhere else for that matter. It’s not a design everyone will love, but suits me. That’s the beauty of building your own stuff.

I didn’t include a lot of detailed instructions here, as most of it is self-explanatory. Please ask questions if you have any about this project or any others included on this blog.

And thanks for stopping by! Be sure to check out our bridge book if you’re thinking about a DIY suspension bridge. Here is the link: Building a Small Cable Suspension Bridge with the Cable Locking System

Images, diagrams, and text copyright 2016 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

 

Wildlife Shelters

Birdhouse I’ve built a lot of bird houses over the years, following one basic design and using cedar when I have it, and only varying the size a bit. The box is easy to make and installs with a screw on the inside back and one into the bottom of the back. I hinge the front with a bent nail or other metal device, making the house simple to hang as well as clean out in the winter. I have these all around the garden and on posts throughout the pasture. Cavity dwelling birds are for the most part insect eaters. Nice to have around in the summertime!

nestboxThis is an illustration from my spousal unit’s book The Complete Backyard Nature Activity Book which has a few other designs for houses and feeders as well.

I’ve also built a number of houses for our duck pond and have had wood ducks, hooded mergansers, and the occasional screech owl make use of them. A wooden hinge on the back of the box attaches to a rope or cable around the tree (run inside hose or plastic pipe). I loosen the rope/cable up every few years as the tree grows.

These larger boxes are pre-loaded with wood chips as ducks and owls don’t bring in nesting material other than their own feathers. I also add a piece of hardware cloth to the entry so the little ducklings can climb out easily.

I built a larger, deeper box especially for the flying squirrels that kept trying to live inside the roof vents of my old house. I blocked entry to their caves, then I figured I owed them an alternative. It SquirrelBoxStuffworked well, both for flying squirrels, Douglas squirrels, and chipmunks. A honeybee swarm also took it over the year I was selling the house. I let my bee-keeping neighbor take it away and when he convinced the bees to move into one of his structures, I got the box back and hung it at our new place.

We’ve had fun knocking first then sticking a camera inside a box to snap a photo. We like to see if it’s being or has been used, and several times we’ve found someone at home. Here are a few photos for your amusement. If you have questions just give me a shout. Meanwhile let’s do what we can to enhance what’s left of the wild areas so these critters can keep on keepin’ on.

Pictured: Hooded merganser, box interior with eggs, wood duck hen and baby, wood duck hen about to bite the camera, tree swallow babies, screech owl and baby.

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duckies

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SwallowBebes OwlsMarch

Images, diagrams, and text copyright 2016 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.

DIY Radiant Floor Heating System

This is about installing radiant floor heating in a slab floor system. While it was done as a new house was being built, in my last house I poured a concrete floor on top of a wood framed floor system and could have put radiant heat in that as well.

Pex-Plan

I obtained a design for the entire system from Supply House where I bought all the parts. They will provide, free, a layout according to your specs and also give you a list of parts you’ll need for the heating system. You can also download a free program from Uponor and also read more information than I will include here.

I opted for a single pump, single zone system for our 980 square foot little house, but opted to have each room a separate system zone that could be controlled by shutting down the water supply. For larger spaces, they would recommend more than one zone with a pump and thermostat for each.

First step was to install a vapor barrier and then insulate. I used extra (rigid) insulation – R15 – to encourage the heat to go up, not down into the dirt.

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Next I added 6×6 welded wire fabric (WWF) aka concrete reinforcement wire and used that to tie down the pipe. I bought a 1,000 foot roll of 1/2” pex pipe. You can get smaller rolls, but no way did I want any connections under the concrete floor. The pipe is very unwieldy especially in a coil that long, so I built a big spool for it and added dolly wheels so it could follow me around as I unwound pipe. The same contraption came in handy later when I wired the house.

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I used zip-ties to tie down the pex pipe. Here are a few photos of the process. We took a lot more photos so we could remember exactly where all those pipes fell. I did not want to be nailing down a plate for a closet and poking a hole in my heating system.

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Then I installed concrete doobies and tied down rebar, just standard practice for a concrete floor.

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I also tied all the pipes together and pressurized them. I wanted to make sure there were no leaks before that 4 inch thick concrete was poured on top of them.

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After the floor was poured, I moved on to building the house. Since I worked pretty much alone and at my own pace, it was a couple of years before it was time to set up the heating system. I built a large utility core with plenty of room for two water heaters as the one designated for the floor would be set low, and space for me to get in and make adjustments. The option for an instant-flow water heater was there, but I didn’t want to spend that kind of money. I just got a standard 40 gallon hot water heater for a couple hundred dollars.

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The heating system consists of a thermostat which is wired into a relay transfer switch. I located the thermostat in the living room, which in our house is a central location. Since I was building the house from scratch, I could easily run the wire in the walls and over to the utility core. The relay tells the system when to start up. A pump kicks on and water runs from the water heater and into the floors. Water from the floors runs back into the water heater. If you can see the numbers on the gauges in the photo, the water going out is about 100 degrees and the water coming back is about 80 degrees.

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The first issue once everything is connected up is getting the air out. If you troubleshoot a radiant floor system by googling, “air in the lines” comes up as the #1 issue. I futzed with it until the air was gone. The second issue was the size of the pump. I trusted the supply house to provide me with a pump adequate for the system they designed, but that didn’t happen. The pump has to be strong enough to deal with the resistance in over 900 feet of 1/2” pipe. You can determine the needs by calculating the feet of head, which I did and the pump came up short. I ordered two sizes up and the system is now working beautifully. The pump doesn’t kick on very often and the house stays evenly heated, ranging from 69-72. I use a Cen-Tech infrared thermometer to see what’s going on.

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Meanwhile, the pets have figured out where the supply pipes are and love to lay down on the nice warm floor.

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With me doing all the work, the total cost including everything involved was about $1,700. We haven’t got an electric bill yet, but considering that the house is so warm and the water heater is well insulated, plus the water going back in is almost as hot as it needs to be anyway, we suspect we’re not using very much energy for this system. It is a wonder that at least in Oregon, there are no Energy Credits for putting in this efficient system. I hope to change their minds about that.

Happy winter!

 

 

Lichen and Moss, Green but not always Mean

What’s that green stuff? People, including house inspectors, don’t like to see anything green on house siding, decking or roofing. As we learned last year, even the FHA has a hissy fit over the color green, and will demand eradication, cleaning and painting, even if the green stuff is not damaging anything.
lichen-HouseIn our case, our 35-year-old house’s cedar siding had a few areas with tiny little hairy lichens happily blowing in the breeze along with a few patches of algae. There were no signs of damage after three and a half decades.

But even though the FHA regulations clearly stated that cedar siding was exempt from the rules regarding wood siding, we still had to provide the funds to pressure-wash and stain the house before we could sell it.

The deed was done and the sale went through. We just hope they were careful, as pressure-washing can be much harder on cedar siding than any amount of lichen.

Lichens are a “plantlike” hybrid of fungus and algae that grow all over the world. The self-sufficient stuff can flourish anywhere as long as it gets a little bit of moisture on occasion. It doesn’t retain much of that moisture and it doesn’t take root, making it easy to remove and control. Lichens don’t bother trees and shrubs unless their growth blocks light to the leaves. But people freak out about lichens anyway.

Moss, on the other hand, is a real plant, and even though anything green growing on a roof is often called moss, this is the real bad guy. Mosses are generally found in shady, wet places. That’s why we see mosses in the woods, especially in wetter climates such as western Oregon. We also see them on roofs, decks, and other structures where debris and water can collect and provide a foothold for it to grow and spread. Mosses break down whatever they attach to, providing a surface cover and moist soil environment for other plants. It’s great stuff, but not if it’s chomping on your house or your bridge!
MossyBridge

This is one of our small trail bridges, in sad need of a good cleaning. It is obviously located deep in the woods, and is victim to leaves, fir needles, vines, sticks, and of course, moss.

My spousal unit came up with an easy way to clean the leaves and other debris that collect on all our bridges. A long-handled squeegee for washing windows makes quick work of the task. But alas, this bridge decking has been adopted by moss mostly because of our neglect. For now, we plan to carefully chip the rest of the green stuff away with a knife, as the decking appears to be secure enough for another year or two anyway.

The under-structure is pressure-treated and so far oblivious to the spongy, green, wood sucking plant. Lichen would have been welcome!

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Thanks for stopping by! Be sure to check out our bridge book. It includes some cool ideas that apply to other projects, like how to put a really tall post into a deep hole when you aren’t that tall. Amazon has the book on sale for about $13.00 right now. Here is the link: Building a Small Cable Suspension Bridge with the Cable Locking System
Images, diagrams, and text copyright 2015 by Marvin Denmark unless otherwise noted. Please do not copy and post my content anywhere without my permission. Thank you.