Thursday, October 31, 2013

the workshop job list

Once the workshop is functional, I have a long list of projects that I've been hoping to start working on.

Here is a tentative list for starters.

cider press
solar dehydrator- Appalachian State University design
solar dehydrator- Larisa Walk design
solar panel ground mount frame
root cellar trusses
sapling puller
log hauler
slow sand water filter
chicken pasture tractor
outdoor oven steel components

a bike power module- bike, gears, flywheel, and support frame. This will be the power supply for a collection of bike powered, farm scale devices.
apple grinder
water pump
grain thresher
grain mill

I have a couple other, far out ideas, but those I'll save for when I get through these.

Saturday, October 26, 2013

Solar concentrating

This post is in response to a call put out on a web blog I follow, asking for appropriate technologies for the energy constrained future. I am calling the generic concept descent engineering, and here is the idea I explored.

An  idea for Krampus:
Idea: high temperature processing
The problem: Maintaining an ability to make materials requiring high temperature processing when fossil fuels are no longer available and a high technology culture and infrastructure are no longer functional.

Two of the primary materials we currently use in our built infrastructure are cement and steel. Metallic tools and devices are also integral to a technic society. These are very energy intensive materials to make. The idea of using concentrated solar energy is explored in this paper, and a description of a proposed facility and associated technology  is described.  The scenario where this facility would be appropriate is a future in which a salvage economy would provide raw materials, and knowledge of metallurgy and related technologies have been preserved.

Current status of technology:
The linked article has a good overview of the general concepts involved, and links to information on the two largest facilities built to date. Solar heat concentration is scalable, so one decision to make is what size is needed for the most likely batch or process in mind, and reasonable to build with limited resources in a future energy constrained world.
The solar furnace at Odeillo, France ,  built in 1969, is currently the largest solar furnace  built, and did research for a number of years.
Another similar sized furnace was built in Uzbekistan in the 80’s, and is also no longer in service.
They both used modern technology for tracking and process control. Odeillo reaches temperatures of 6330 F, which is much more than needed to melt ferrous metals.
Overall facility description: A high temperature processing facility would be a large investment , with the main support structure for the parabolic concentrator being  on the order of 50 meters tall and 50 meters wide. While the future capacity need is uncertain, it is unlikely that very many would be justified.  The main components are the array field, the large parabolic concentrator, and the focal receiver. The engineering challenge is to design a solar furnace facility similar to the existing ones, but assemble and operate it in a technology and resource constrained world.
There are other high temperature applications this facility could be used for also, further justifying the effort to build it. For example, photochemical processing,
photo catalytic processing, and high temperature ceramics

Assumptions on design limitations:
The facility should be designed to enable replication of its constituent components.  Smelting and making steel structural members, heating limestone to make lime or cement, and melting sand to make new mirrors are all things that a solar furnace would be able to do.
Sizing the facility for reasonable production levels:  Sufficiently high temperature is only part of the sizing  question. Sufficient total heat available will define how much mass can be brought to smelting temperature, so maximum rate and total BTU collected in one day will govern the batch size.
Batch processing: Due to the high temperatures needed, it is not envisioned that a solar processor would store heat in some medium for long runs like CSP steam generation plants do now, rather the unit would need to be designed for single day batch runs. This implies batch limits based on the processing time and time to bring the mass up from ambient to processing temperatures. This will be the main variable for sizing the collector field and parabolic concentrator. The Odiello facility has a concentrator of 1800 square meters, and 63 heliostats.
Utilization of unused heat: For periods when insolation is not adequate for smelting or limestone calcination, it might still be collected and used for lower temperature activities and thermal heat storage. A facility like this would lend itself to the concept of collocated industry, where synergies in energy use and material streams are optimized. District heating schemes, common in Europe now, might also be a side benefit.
Location criteria: Locating a solar processing furnace would of course primarily driven by maximum solar insolation. A south facing slope of the site would help with efficient land use and mirror placement. Proximity to raw materials would be important also. Limestone deposits would be needed for making lime or cement, and steel or iron nearby would minimize transport costs. Mining the ruins of Las Vegas might well be a good first location.
Smelting steel: Steel is relatively straightforward to melt, but assuring the ability to obtain the desired metallurgy and mechanical properties would necessitate some ways to get the alloying mix right without modern instrumentation. Reference books explaining early steel works, which relied on visual indications, would need to be secured, studied, and the methods practiced. One advantage of solar heating for smelting scrap is that it does not introduce any impurities into the charge. This link shows that the knowledge to do alloys without modern instruments is available, but needs to be collected and the skills relearned.
example of “low tech” steel making

To effectively control alloy content, scrap and salvage would need to be categorized and then blended to get the intended mixture in the melt. This will require coordination with scrap and salvage businesses. 
Solar heating: A key engineering challenge will be figuring out how to direct the solar ray onto the mass with a high efficiency, while controlling and monitoring the melt. Also, a solar field geometry similar to Odiello will have the rays coming in to the focus area horizontally, but a crucible full of melting or molten steel will need to be oriented vertically, with continuous sides in order to contain the liquid.

Making lime and cement:  The need for cement and lime as building materials in a future energy decent era would be less than now, but there will be specific applications where it would still be worth the investment of energy.  Some buildings in this future might well revert to a long term sustainable design approach based on stone and lime, with high initial effort to build, but with a lifetime measured in centuries. Cement, and resultant concrete,  being a rather short lived material, may recede in use.
links on making cement and lime:
This last linked article is specifically about the design parameters and economics of making lime with a solar concentrator.

Allayed necessary technologies:
Making mirrors: A facility like this would need to be self replicating in some respects. One aspect would be making new mirrors for replacements or to build another facility. The following links show methods of making plate glass with relatively simple methods, as well as silvering the glass.
how to make plate glass
silvering glass to make mirrors
Tracking:  Without current electronic control systems, based on plc controlled stepper motors, sensors, and machined mechanical components, tracking would need to be done with simpler methods. Clockwork type mechanisms have been used in the past to aim small heliostats, so some design work would need to be done to make a large, strong actuator that could withstand transient wind loads and maintain adequate accuracy. It may well be that a combination of clockwork mechanism with some daily human adjustment would end up being the optimal way to solve “low tech” tracking.
Crucible melting ferrous metals

making refractory materials adequate to contain steel smelting is a challenge that needs research. Current crucible materials are based on very specific chemistry and processing, and I have not yet found a low tech alternative.

Sunday, August 11, 2013


The pole barn is essentially done. All I have left to do is finish a bit of drywall in the enclosed workroom my friend Barry and I built inside. Now to fill it up! We've already taken a trailer load of long term storage items up, and I'll be moving mowers, other stuff up to the barn and freeing up the garage for actually parking cars.
It has mows on each end, so we can store small bale straw or hay.

Any farm needs outbuildings, but they are not cheap, so one will be enough for quite a while. It's hard to find level ground on our farm close to the house, so that limits us as well. I will probably build a chicken coop along the lines of Harvey Ussery's concept in  a couple years.

We used local contractor to build it, as we don't live there yet, and even if we did, this would be at the limits of my skills to do, and couldn't do by myself anyway. We are getting to know the neighbors, who are all very nice, but enlisting them in a barn raising is a bit much just yet.

Photo taken in the last couple days the contractor was on site. Dirt work took only two days, the pole barn work took the better part of two weeks. Very small crew, so really it went pretty fast. We decided on two 12' sliders so one can drive through, making it easier to unload hay, or access stuff from either side if the main floor is blocked with stored equipment.

Barry framing in a window. Yes, I have a window from the workshop out in to the barn. It will be good for cross breeze in the summer, and it was a leftover window I had been hanging on to for a couple years, so might as well use it. Will have a double door into the workshop, for those bigger projects.


I made the ceiling joists extra strong, so it can handle hay storage above. 12" I joists on 16" centers, because of the 20' span. Got a lot of good help from the lumber yard that supplied the material. Made me glad I didn't go to Menards for a "cheaper" price. This lumber yard has pole barn designers, make their own trusses, and can actually supply dimensional lumber that is grade 1, or even select structural. And it was straight! No sorting though piles of bowed, twisted stuff at Menards.

Next year I will also add power, and set up the rain collection tanks.

Sunday, May 12, 2013

hedging bets

First section of hedge aka "living fence" got started this April. I did not have time or inclination to follow the instructions exactly, but we'll see what happens. I also haven't decided how elaborate to get with actual hedge laying. It is an art in many sections of Great Britain ( or is is England? I'm never sure what to call portions of that Island) but I gotta get the trees out of the ground first. I have found very little example, information, or sources for the recommended Hawthorne species here in the States, so this kind of an experiment.

Starting out with Osage Orange, also known as hedge apple. Wisconsin might be a bit far north from its native distribution, but who knows, it's getting warmer every year............

 Here are a couple shots of the process. After leaving the seed heads out all winter to go through their normal breakdown, I slurried them with some water, then dribbled the slurry in my tilled trench. Hard to see in the photo, but there are hundreds of seeds in this mush. So now after covering, we hope for a good stand of sprouts, and thin if necessary. We've had some good spring rains, so hopefully I will be able to post photos of new seedlings next post.

This is about 80 yards of planting. I have quite a stretch that I plan to hedge, so if results are good, I'll be asking friends and relative for more hedge apples this fall also.

Sunday, April 21, 2013

emergent behavior

Read an interesting article in Wired about emergent behavior. In essence, large groups of individuals, by following simple rules of behavior, can express group behavior which cannot be predicted by examination of individual behavior. It's kind of like the concept of tipping points in group dynamics, but can occur in very simple organisms.

The article did not discuss how the initial simple rules come to be, but I am thinking this is where evolutionary pressures and adaptation are played out on a group level. If this emergent group behavior was not in some way adaptive and successful, it would not continue.

So I got to thinking about humans, and whether you could really say we have emergent behaviors. We are a lot more complex than an ant, fish, or bird, but there do seem to be repeated patterns in history, especially when you get a lot of us crammed together. It's just that a lot of these behaviors ( and I am still not certain if they can be called emergent) seem really detrimental. War, genocide, mob rule, riots, why do these seem to be common reactions to environmental stresses? Is religion an emergent behavior? How many people amass in a tribe or group before thoughts of immanence and the transcendent occur?

Not sure this will ever get answered, as we have so many ways of transmitting information besides direct face to face presence, and there are a relative few individuals that have larger, more outsized influence than the majority.

I may have to read some E.O. Wilson, other social theorists and see if this has been thought about.

And, some emergent behavior of another kind:

These little guys (cabbage)  popped up several days ago, and most of the other seeds are now up.

Friday, March 22, 2013

snow melt

Having a slow spring / late winter is good as far as I'm concerned. We need the precip, and I'm not as tempted to start my tomatoes too early. Hopefully we will get a "normal" spring, with no freak early hot spell, followed by a killing frost like last spring. Next trip up we will scout the Mark Shepard installed swales, see how the water collection has done. There is one stretch that may need some work, he was trying to compromise between following the contour elevation and still leave a uniform crop alley, so we are sloped a bit too much. Hopefully just some shovel work. Next trip I'll also start digging the holes for this spring's fruit and nut tree order, as long as the ground has thawed.

Had a nice visit with the neighbors last trip, they are very busy with their small dairy operation, and the yogurt they make is the best. The latest addition to the heard is named Patsy. (All the cows are named for country western female singers) The girls have ordered like 40 chicks to arrive shortly, and they plan to give them all names.

I don't think we'll be naming our chickens.

Saturday, February 23, 2013

joist tables

Well, getting closer to pole barn time. We'll selected the contractor, have had the dirt mover come out to measure the site for his quote, so now I turn toward figuring out the workshop I plan to build myself. this will be a 20' x 32' section of the barn. With 14' eave height, I plan to make an 8' ceiling, and use the space between the ceiling and the lower truss chords as storage. Meaning- the ceiling is actually a floor, and needs to hold some amount of weight. I've never designed in wood before, so am learning about joist tables. I had never thought about choosing live loads or figuring out what the density of hay is, but need to make sure I get this right. I also want to try to avoid columns in the workroom so we are talking 20; spans. I am now learning about LVL- laminated veneer lumber. It's more expensive per board foot, but stronger, so I will be doing some comparison shopping. Pole barn is scheduled for mid June, so I'll do the workshop in late June. We are figuring we will probably do the bike trip with Joe in July, so the summer is filling in rapidly.

Here is a photo from this winter, me doing my first field dressing.

Sunday, January 6, 2013


high density polyethylene is the plastic of choice for so many things. The drought in our area does not at this time look like it is going to end, as there has not been that much snow or train to adequately rehydrate the soil. So....., am getting ready to invest in a water storage tank, to be used to drip irrigate our trees. We almost bought the setup last summer, but I don't want to loose any more trees, and we will want the tank anyway, for when the pole barn is built and we collect rainwater from the roof. Figuring out the drip tape and a wagon to haul the tank will be next. Several sources for the tanks, even Nelson's had some selection last summer. I may stop in next trip and see what they have, and if I can order one.