peak moment

While I was still down in Guatemala I got in touch with Peak Moment, a television show covering peak oil issues, and told them about what i was up to. We kept in touch, and late in the summer of '10 they came out to Aprovecho and filmed several shows.

If you do any research on peak oil, you'll eventually end up watching an episode of Peak Moment, and for good reason- they do some really excellent programing on local self-reliance and creative responses to peak oil and climate change.

It was nice finally meeting Janaia and Robyn, and it was great to film a show with them. Here it is:

While they were at Aprovecho they filmed several more episodes, so keep an eye out for those as they may be showing up soon. And be sure to check out Peak Moment's youtube channel, there's a lot of great information out there.

human powered machine workshop

In the summer of '10 Aprovecho hosted a workshop on pedal powered machines which i had the pleasure of planning and teaching with my friend Neil Kearns (check out the previous post to see one of his machines).

A handful of folks came from around the country and Canada to learn about pedal powered machines and to collectively build an electricity generator.

Neil and I built a generator in advance of the workshop to ensure that we had a solid working model to base the design off of. This is what we came up with:

The workshop started with an introduction into the basic concepts of using human power- gear ratios, drive types, efficiency, etc. (I won't go into detail about those things here, but if it's something that you are interested in i'd highly recommend picking up a copy of The Human Powered Home).

We started in pretty quickly to building the generator. As an instructor, once more, the challenge was present of how to keep everyone as engaged as possible. There were some lag times for sure, but overall things stayed pretty balanced. And if i remember correctly, i only had to jump in once or twice to help with the welding, otherwise it was all the students.

The generator that we built used a deep cycle lead acid battery (like the kind made for RV's or small boats). A small motor pulled out of a "dead" treadmill on craigslist. A multimeter, a diode (also pulled from the treadmill), an inverter and a whole mess of wires.

I'll explain a little more about the components we used. Deep cycle batteries are designed to hold a significant charge and release it over a sustained period without needing a recharge. These are much better suited for a DIY generator than a car battery. Car batteries are designed to be charged and dispelling electricity constantly. One thing holds true for both batteries though- never drain all of the electricity. Both types need to maintain a certain level of charge in order to function properly.

To make sure that our battery wasn't undercharged, or overcharged, we hooked up a multimeter to tell us both the charge level of the battery and how much electricity was being produced at any given moment via pedaling.

You may wonder what the motor is about, well, a cool fact about electrical motors is that you can use electricity to make them spin or you can spin them to make electricity. So that's just what we did, set the fly wheel of the motor on top of the wheel of the bike machine, using the friction of contact to drive the motor wheel. The quirky part about using a motor is that if you don't wire it properly you'll start generating electricity with it and once its sent enough electricity to the battery the electricity will come back and start spinning the motor!

As funny as it was to play this little game with the motor, its totally useless for generating anything. That's where the diode comes in. Diodes are semiconductors, often used on circuit boards, that control the flow of electricity. Soldering in the diode into our circuit kept all of the electricity from rushing back out of the battery and into the motor.

Inverters are devices used to change electricity from direct current (DC) to alternating current (AC). When using a re-purposed motor to generate electricity, direct current is what you get. And while there are some things, mostly RV or marine-based, that use DC, just about everything else uses AC. (There's a long and fascinating history behind the two currents, which i won't go into, but its definitely worth a look on wikipedia).

And the wires, well, you know what those do.

Here's a video of the generator powering an angle grinder. Kindly ignore the cigarette.

If you are interested in building your own pedal-powered electricity generator there are plenty of designs out there on the web. Here's a couple I'd recommend checking out:

http://www.pedalpowergenerator.com/
http://www.instructables.com/id/No-welding-pedal-generator-stand/

Also, before building a pedal power electricity generator you may want to check this out important article from Low-Tech magazine:

http://www.lowtechmagazine.com/2011/05/bike-powered-electricity-generators.html

the washing machine

Somewhere between the water pump and the straw chopper was the washing machine. It didn't go very far in my hands, but its worth bringing up because it did go somewhere interesting.

A phone call was made to aprovecho by a couple looking to commission a pedal powered washing machine. The call was passed along to me and i agreed to take on the project. I started collecting materials and then started tearing things apart.

Once i had a sense of how it worked i started contemplating how best to run it. I turned to the internet for guidance. There are a number of interesting pedal powered washing machines out there:

http://www.treehugger.com/clean-technology/cyclean-pedal-powered-washing-machine.html

http://homelessdave.com/hdwashingman.htm

 http://www.youtube.com/watch?v=KzTKDw-b9uo

 http://www.youtube.com/watch?v=NYmK9Rsh4Pg


However, i didn't get too far into before some issues came up that kept me from moving forward. Namely the need to prioritize working on other simultaneous machine projects. So I passed it on to my friend Neil and here's what he came up with:

Neil's a pretty brilliant guy, be sure to check out some of his other projects on youtube, namely the bio-char, plastic-to-oil conversion and other human-powered machines. 

renovating the shop

When I first got to apro and started using the shop it looked a lot like this (though not this, this is my mess). It was a storage space with stuff everywhere, parts entirely impassable. I did some rearranging of things earlier, got it looking good. But once I was there for a while I was told the woodworking shop was going to move in there with me. So I was asked to condense.

A former employee, Ash, had suggested to me at one point that I move everything to one side of the shop. I could even open up the office area to use the floor space. At first I really didn't like the idea, but in the light of splitting up the shop it was a very good idea. I proposed it to the staff and they accepted.

This was going to be the first to go:

The plan was to leave the upper part as a loft, the underside opened up as the welding area. This made sense for a couple of reasons. Aside from the space sharing, the upper part of this intereior structure was getting pretty moldy. Having the welding going on under the loft meant that curtains could be hung from the loft to protect others working from getting flash burn. It also got the welder closer to the actual plug, which helps. And it meant that the space had a single door to be entered through, rather than having to open up the big garage door to go in.

First I moved everything away from the office/apartment structure. Then I started tearing things apart.

It was a lot of work, maybe a month or two, mostly by myself. Here's the condensed version.

There were massive amounts of debris. And ants. Lots of carpenter ants.

To finish up the structure I salvaged most of the wood pictured above to build the deck on the loft. I also used it to build, I don't know what the right term is, foot boards along the perimeter of the former office.

Then came cleaning. After that, moving everything back into place.

It always amazes me that, despite all of the over-documentation that I do, I seem to always miss at least one really important shot. In this case I'm missing everything all put together nice and neat. The wheels and bikes were eventually moved to hang overhead, as they did on the other side of the shop, just to the right of the loft. The space really opened up significantly. Things fit well, they were organized well, it was a good move, I'm glad it happened.

straw chopper 6

Once both ends of the container, lets call it the hopper, had been put together it was time to weld some bracing between them.

 

I tacked a temporary brace between the two ends, in order to keep it straight and true, and then welded in one of the supports for the top. Then the next.

  

After that came the two pieces that would hold the grate in place. 

  

The grate, a metal mesh i found, would serve the purpose of filtering the straw. Once the straw was chopped finely enough, it would pass through the grate into a container below.  Until then, it would swirl around inside of the container. I was pretty proud of the mesh, frankly. Because i thought it a good idea, but also because there happened to be this one random piece of metal that was rusting away and bent out of shape that i managed to save for the job. It took some pounding with a hammer, some bending, some wirebrushing, but it turned out pretty nice. 

 

  

The best part was that it fit in the frame perfectly. It fit so well that i didn't even need to weld it into place, its natural tension kept it snugly put. This was a big relief, i was concerned about welding it. Another perk of the tension fit was that it was then removable, making the whole thing easier to clean, access, repair. 

At about roughly the time that i was finishing this portion of the machine i undertook a large side project- renovating the shop space. I'll retain the details of that for a later post, save that it took a very long time- maybe a month or two. And somewhere in there Chris, the natural builder who proposed the straw chopper, let me know that the machine was taking too long. The deadline in mind was a natural building workshop, the idea being that the chopper would be used to chop the straw for the workshop. Get it done, i was told. Fast. 

I understood the need to finish the project, it was definitely taking too long. Though it was disappointing to let go of trying to make the thing look as clean and nice as possible. No more energy would go into joint design or hiding welds, only pure function mattered. 

 Since i had the hopper more or less finished, i needed to build (or find as it were) a container for the chopped straw to fall into. Also, to create a structure for pedals, a wheel and a rear derailleur. 

I found this big blue barrel out in the scrap yard- it was perfect. 

I welded a frame to fit around the top. I made it tight enough that it would fit snugly, as opposed to welded on, and therefore removable. Next i made a stand to permanently affix a bike wheel to, and for the barrel to sit on top of.

 

 

 

The bike wheel, if you didn't see from previous posts, will act as a pulley. A thin belt, taken from a clothes drier, goes around it and runs the lawn mower blades. Below i have it mocked up for placement. The primary thing that i was trying to figure out was the distance beyond the edge that the hopper would have to sit. 

Once i had the placement set i propped up the back end with whatever i could find and welded two supports in place. 

Then i constructed a support structure to hold up the rear. Because the backside of the hopper didn't quite reach the end of the barrel, i had to run a piece of angle iron across the gap. 

Next, i welded on a small tube into which i could insert a belt tensioner. In fact, the tensioner from the very same drier that the belt came from. There are several reasons that a tensioner is important- first because it puts the proper amount of tension on a belt for it to drive well, while still keeping it flexible enough to remove the belt when necessary. Second, belts (as well as chains) stretch over time, and a spring tensioner will automatically adjust for that. 

With the pedals, i just needed a simple structure to hold the cranks up at a good height. Really, all it had to be was a bottom bracket welded onto a post.

In order to determine the height that i wanted the cranks to be i performed, what has come to be known as, the "brad and heather test." Brad is really tall, heather really short. The perfect test for height compatibility.

Everything checked out fine. I figured out that i could leave the pedals at their current height so long as the seat extended greatly and was also not attached to the structure.

In addition to having a tensioner on the belt, i would need to put one on the chain as well. Though there wouldn't be a need to change gears, the second function of a rear derailleur is to act as a tensioner. I had plenty of those lying around, so i grabbed one that looked good and tacked it on to the frame. 

 

  

You'll notice extending from the pedals to the right is a new long piece of angle iron. I had to put that in there because the machine kept creeping forward away from the pedaller. This way with the seat on top of bar the weight of the pedaller would keep the whole thing still. 

At this point it was pretty much time to wrap it up, everything was connected, the gear ratios felt great- the blades spun like a whirlwind. My initial thought was to seal in the hopper with sheet metal. But it occurred to me while building it that it would be much nicer to be able to see into the hopper. Seeing the result of your labor is the majority of the fun of human powered machines. At least it is for me.  

At one point there was this guy Ash (talented natural builder, all around great guy), he bought a truck and had the rear windows taken out because they were plexiglass. I remember asking him if i could hold onto it because i figured it might come in handy. And indeed it did. There was just the right amount and just the right size to enclose the hopper with it. 

To close up the bottom i used sheet metal, easier than the plexi, plus i needed the flexibility of the metal to create an angled and curved shoot to direct straw into the barrel from the overhang.

Both the plexiglass and the sheet metal were glued in using epoxy. Unfortunately, even with roughing the surfaces and using clamps they still fell out periodically. With the sheet metal, welding it in with stick wouldn't have worked. Tig could have, even mig. But those weren't options. The plexiglass could have been bolted in, but that would have meant more work and more expense. Time and money were against me. 

There were a couple final touches to make before it could be officially pronounced finished. I had to have a seat that could lower and raise, yet be independent of the rest of the machine. I also needed handle bars. And, as it turned out, the whole thing would fall toward the rider (not sure why) so i had to weld additional supports onto the back and put cinder blocks on them. 

For the seat, i cut apart an adjustable stool and welded on a bicycle seat post with saddle (saddle is the term for bicycle seat). And for the handle bars, a long pipe with the right diameter to accept a quill stem handle bar set.

And there it stood, finished at last. Or at least finished enough to work. I had in mind that once the deadline was met that i would come back and smooth out some of the rougher parts. For example, i never built a lid for it, just put a board on top. No time for lids. 

Another thing i would have liked to change was the way the straw was accessed. Either the whole kit and kaboodle had to be lifted off the top, or you had to bend down in and scoop it out. Neither was ideal. 

And to illustrate the process: 

The bucket on the left is the more finely chopped straw sifted from the coarser straw in the bucket on the right. The fine straw is ideal for doing finish earthen plasters- it has enough fiber to hold the clay together, but its small enough to disappear visually into the plaster. The coarser stuff, used for base coats of plaster, looks rough, and the individual pieces of straw are clearly visible from a distance. 

This is a close up of the finely chopped straw. Using the machine i built it took an hour of steady pedaling to produce one gallon of this ideal material. For comparison, 30-40 minutes of a weed whacker in a trash can (the current natural building standard) produces -i'm estimating- 15 to 20 gallons. Unfortunately, this disparity was too great for the pedal power straw chopper to be adopted into use by the natural building program. It was a let down, but i certainly couldn't argue with the conclusion. Regardless, it was a significant personal success- inventing and building a functioning machine from scratch with limited material and financial resources.