Job's Done (in the WC peon voice)

I met the president of Mali today.
We're standing next to the Butterfly, which was presentable!! Barely. Wow, it took a long of work and some serious cunning/refusal to accept reality to pull it off on time. After not being able to remove the mold on Monday, I nearly lost hope. Then, when we successfully pulled the mirrors off the mold, I was sure everything would be fine: Then, when we got around to gluing up new mirrors on the mold I was sure we'd fail miserably. We almost did. See here, we make a mix of white wood glue and crumbled styrofoam.

The idea is to make a little mountain on each one.

And after placing the plywood backing on it

and weighing it down, the idea is that we'll have a nice lightweight backing. Unfortunately, I wasn't able to manage the (*somewhat chaotic* due to ti,e sensitivity of fast drying glue) situation completely, and a couple glue/styrofoam mixes had too much glue, which leaked down onto the mold and under the mirrors, meaning that when we pulled the mirror wing off the mold, some mirrors refused to follow

Leaving us with one ugly, cripple wing less than 24 hours before the Salon.

Enter the refusal to accept what seemed like a hopless situation. It oculd be called 'moving into salvage mode'. We pried off the mirrors which were glued to the mold and glued them back on the wing in a helter skelter interpolation of the angles best described as eyeballing. It did the trick insofar as all the mirrors were there and more or less oriented properly.

By nightfall, we had finished the structural modifications and it was time to transport. I spent until 3AM washing mirrors and painting the machine while doing an anti mosquito dance.

However, the president didn't do much more than a brief pass-by photo-op for the Butterfly.

The Helios, on the other hand:

Was much more attention grabbing, what with the flaming stick and all. ATT as he is known, admitted to being impressed and congratulated us on our work. After learning our plans of sharing the techniques and ideas associated with Solar Fire through workshops, training etc he said we must absolutely get in touch with his minister of training and professions. We also suggested a further, more personal demonstration at some point in the near future, since regrettably we had nothing cooking, he seemed agreeable to the idea and so we'll follow the required protocol and try to set that up.

Am pretty wrecked after the 19hour work session yesterday, only 3.5 hours sleep and a long day standing in the sun exposing today so I'm going to go sleep. I'm getting soft I tell ya. Back on the Cuban mission we did that for like a week straight.

ArRgGH!!

Mold's still wet.


Hope is not yet lost though.

If we glue up the last wing AT the salon and install it Thursday morning, no one will be the wiser.

Failing that, we can at least hope to have a fully functional model by the end of the salon.

Good thing the salon is a bonus, not something critical.

Still.

Mold-ness

The process we're going with is the straightforward approach.

First step is to prepare the mirrors for receiving the plaster: we use tape to seal all the cracks between the mirrors so that plaster doesn't get around back of the mirrors. Then we built a frame around the edges to allow us to build up the thickness.

Then we pour the plaster (into which we mix some reinforcing fibers and two wooden beams for rigidity).


Then we let it dry.

We finished up on Friday and left it to dry. I asked if it was possible to work on the weekend, because that would speed things up, which we really really need. The Salon de l'Habitat de Bamako 2008 starts on the 21st which is Thursday of next week. If we didn't work the weekend in meant that we would get in Monday, make the first copy of the wing for Tuesday, make the second copy of the wing for Wednesday and then pack everything up that same day and move out to the SAHABA 2008 convention. That would mean zero room for error. Again. Sigh.

The crew saw where I was coming from and agreed to come into work today (Saturday), but what do we find? The mold, that much is certain, but still wet. We can do nothing except put in outside in the wind and the sun, hoping it will speed things up.


We can't risk taking it off tomorrow, because it is a really big, thick mold and clearly needs more time to dry than anticipated.

That means we get down to business Monday.

That means no room for error.

Again.

Sigh.

In my defense: I told AMADER I would need a month to make this prototype. They administrationed their administration for a while and gave the go-ahead with only 3 weeks to go. If we had another week we'd be laughing. As it stands…

Boiled water

The first step to forcusing is determining where we'l place the mirrors. Since we're talking about inclined mirrors arranged on a flat surface there is bound to be some shading/blocking issues. Here, Djadje moves two mirrors around the wing and draws a rough guide to mirror placement so that we can space the mirrors effectively.


To space the mirrors effectively we--
Wait! Stop everything! Emergency! The teapot is broken! All work ceases and Michel heroically breaks out the oxy-acetylene torch and welds it back together. Phew. OK back to work, nothing to see here.


Using the mirror map we drill holes and place three screws in a broad triangle beneath each mirror. By placing a mirror on the screw-tripod and by varying the height of the screws we can incline the mirror such that it reflects onto the pot. You can see one mirror is on target while another is hitting the building.


Once we have all the screws properly adjusted (it's not enough to do it for one time of day, it has to work all day, so once you do the initial focusing you have to keep it on target for a day or two and observe how the mirrors react to different insolation (INcoming SOLar radiATION) angles and adjust accordingly.) we can proceed to backing the mirrors. I'd settled on styrofoam/glue mix. We bought a large quantity of styrofoam for next to nothing and got to work busting it down.


It wasn't the easiest process:


But it did the trick. The problem was how to weigh down the mirrors so they would stay in contact with the screws. For our first try we makeshifted a fast solution because the glue was drying fast:


Afterwards we reflected and determined that we could glue the mirrors and then tie them down using wire. We found out that wire worked so well we didn't even have to glue them.


That means that we could mount the wing and adjust the mirrors a little bit while we saw how they behaved on the machine. They behaved pretty well! We managed to boil some water, and we're at only half power! I assume we're at around half power, but you never know what ol' bucket-o-rocks is up to.


This bodes well for the final product, but the hardest part is yet to come.

The next step is to build the mold, and then use that mold to stamp out copies of our original. It will not be easy. Again, if anyone has any ideas about how to effectively make a very large mold of these mirrors let me know.

Geometry Achieved

Today was a wicked day.

Not only did I get a drive to work (instead of spending an hour walking and taking a packed van) but we basically finished the frame for the Butterfly (my variation on the Papillon) and proved the geometry is sound).

There were a number of problems that I had foreseen (weight distribution, pot placement, spaces between mirrors, mirror shading etc) and had assumed that we would be able to solve with a certain amount of elegance. Kudos to us for actually being able to.

Also, the butterfly is a test of construction precision, because unlike the other Solar Fire technologies, this one is pretty rigid. The Vesta, Apollo and Helios, however, all have movable mirrors and can be modified fairly easily. The butterfly is a one-piece reflector that must follow a pretty precise line of movement to track and reflect the sun easily. Initial indications… indicate… that we achieved an acceptable level of precision. Must be due to all the vicegrips:


And our counterweight (speaking of elegant solutions, note the paintbucket filled with rocks tied opposite the wing):

The butterfly works like this: the two wings face the sun directly, and will eventually be covered with 10cm by 10cm mirrors (like the one I'm holding)
which will reflect the sun onto the pot at the center. The paintbucket-counterweight will eventually be replaced by another wing, so the weight will be balanced. We've substituted that wing for a counterweight because I didn't know how this experiment would turn out and didn't want to make two wings if their shape/construction weren't for certain. I reverse engineered this design by looking at some pictures of the papillon, and so nothing was for sure.

The mirror angles at the edges of the wings are pretty acute, which means that we'll have to fill fairly large spaces with the woodglue/sawdust or Styrofoam mix, but luckily I happened across another type of plastic foam with better cohesion than Styrofoam, so we'll be able to cut it to fill the majority of the space without using large quantities of glue:
However well things went today, the process is nowhere near finished. Once the geometry is finalized, we move on to calibrating the mirrors. There are 100 mirrors to calibrate, which will take a solid amount of time (especially with the heat of the sun these days!). After the configuration, we'll have what we call a master mold. That is, we'll have glued all the mirrors at the proper angle, but in order to avoid having to calibrate 100 mirrors each time we want to make a wing we're going to make a mold of the original wing.

That's a pretty big mold. The parallelogram that makes the wing is short side: 70cm, long side 150cm and width 100cm. We're probably going to go for rebar reinforced plaster or cement (plaster is way easier to work with since it doesn't bond to mirrors too fiercely) but I don't know yet. If you've got suggestions on how to avoid breakage, let me know. I'm slightly worried, but have faith in the guys I'm working with. I don't have extensive materials experience, but they sure know their stuff. I'll let you know how we solve the problem (and the various ways we might fail).

Consider protocol disregarded (surprise surprise)

Monday morning and I 'passed by AMADER to say hello' and incidentally wondered aloud about the state of the financing 'because the SAHABA 2008 is only three weeks away'. There had been some motion, but still no money. They had received tacit approval to include the creation of the domestic solar cooker in their 'global budget' for SAHABA, but had not yet compiled the global budget etc. I said look, if I buy materials now will I be paid back? She said she couldn't guarantee anything, since it's not in her power, but given the tacit approval and the general enthusiasm of the department, I could pretty much count on getting paid back.

Good enough for me. To the truck! To the store! To action!

And by action I mean careful contemplation of the task at hand:
Here is the first little science experiment to determine how we are going to back the mirrors on the papillon. If you check a previous post, there's a picture of a papillon made with curved polished aluminum. My idea is to use mirrors attached to plywood. The question is how to support the mirrors at the appropriate angle. Here I'm mixing various quantities of wood glue and sawdust, or crumbled styrofoam with wood glue. The goal is to have something rigid, lightweight and cheap.

During the long lonely nights while the cyber is closed I amuse myself by contemplating the geometry of the papillon by drawing it out to scale on my bedroom floor:


The results are in! Styrofoam is much lighter and more waterproof, but sawdust is more rigid. More tests to follow, including other materials etc, but already we've got something workable for the demonstration.


Have you ever heard the saying that you can learn a lot about a workshop by the size of it's drill-press?


Basic geometry and initial structural problems overcome. Tomorrow we should start with the mirror focusing to make the master mirror mold. In an upcoming post I explain the process in detail...


Here's a picture of the Malian Minister of the Environment lighting a stick with Solar Fire:


And this evening the association Tile Tasuma (Solar Fire in Bambara) had it's first meeting. From left, President Ibrahim C Tomota, Secretary General Faguimba Tounkara, Assistant Vice-President in Charge of Training and Technology Djadje Samake, Vice President in Charge of Training and Technology Lorin Symington, General Treasurer Lalla Samake, Responsable de la sensibilisation (responsible for public relations, more or less) Boubacar Sidibe. Not pictured are Karim Sanogo who is Secretary in Charge of External Relations and The Accountant):


In summary: tech development is in full swing, hooray!

Le Blog en Francais... encore!

L'autre address etait un solution temporaire. Les blogs sont maintenant disponible a

Accueil du site > français > Projet > PFS Mali > Les blogs traduit en Francais

de http://sun.solarfire.org/

ou, plus simplement: http://sun.solarfire.org/articles/spip.php?rubrique18

Merci Olivier!

The National Forum on the Environment

Right. Remember what I said about blog frequency and craziness? Yeah.

So Monday rolled around, and there was no action on the budget. Not only that, but the guy who was supposed to help bring the Helios to CNESOLER didn't show up. I decided to go to the director of AMADER's home energy dept to speed things up. He understood, but couldn't influence things. I told him about my decisions regarding CNESOLER and he agreed that it would improve chances to get funding if I partner with a government establishment.

I went home without having accomplished much.

Tuesday started out the same… I was in an office trying to move things along when a brochure on the lady's desk caught my eye. The Mali-Folkecenter is apparently hosting the National Forum on the Environment. MFC is a pretty big operation, and I hadn't yet made contact with them, though it was in the plan. It didn't really connect just yet that I am in Mali. I look at the date, it says 29th of Jan 2008, not knowing what date it is I think for a moment, that's a shame that I missed it. Wait a minute… that's TODAY! At this point I still have significant doubts that we'd be able to do the necessary paperwork to get a vehicle, or register me or whatnot. Still, might as well ask.

Bam. To the directors office! 4 hours later we had dis-assembled the machine and transported it to the Palace of Culture, where the Forum was taking place. They gave me 10,000 F CFA to buy food to cook for people and I was on my way.

The next day we(and by we I mean she) cooked up a big stew for everyone.
Solar Fire Style: maxed out thermometer (that means +200C)
Ibrahim C Tomota says: Solar Fire, awww yeah.
So much stew.
lol poor SK-14, all broken and neglected:
Then there's the Association of Women Engineers who had a stand promoting their use of cardboard and tinfoil cookers with a heat resistant bag. They have to be imported from Holland, but have the advantage of being able to be transported like 30 to a backpack.
Mmmm so much solar cake. We made the mistake of using pots that were too big for cake, and they were burning at the edges and not done in the middle, so we massacred it a little bit and put everything on the baking trays.
I probably served cake to like 100 people.


It was good to the last crumb.
Haha in our enthusiasm for cake we let the focal point wander… on this oven we built the exterior side walls out of wood to save on tinsmithing, but we'll probably not do that in the future, considering it smolders a little if the focal point hits the tin on front.
I made tons of good contacts, met the minister of the environment a couple more times, and impressed the people who work at CNESOLER (I was hosted by their stand at the forum). Everyone is really enthusiastic, so we'll see what we can cook up.

This weekend is catch up on sleep time and kit maintenance. This coming week, if the money isn't available to start the papillon prototype I'm just going to buy enough materials to get started... the Habitat Salon is less than 3 weeks away, and is important enough to disregard protocol (what? me? disregard protocol?)