After a week and a half of cleaning, moving tools, and re-organizing the basement, my workshop is now nearly reconstituted. It was in early January when I scavenged every last useful tool from my house and the coffee shop, and put them in the Camera Craft garage. It took 3.5 months to build the helios 5 roaster oven from sheet metal and scraps & get it all working. Now that it's temporarily set up in the back of the downtown shop, I have vacated the garage until we are ready to install the solar power system. Costs less to just rent it as storage for the time being, than to be moved in and using it before it is strictly necessary.
Looked into buying the next round of carbon credits this week in order to offset the fuel we are burning in the meantime. We were featured in a segment on News First 5 this friday & we showed them our helios 3 roaster. It's kind of an inconvenient time right now, because everything is in the works, but nothing is complete yet:
-> He helios 4 is decomissioned as of last week & pending sale to PRI for conversion to a solar plastics melter.
-> The Helios 5 is running fine, albeit on natural gas. (It has finally stopped scraping and eating coffee beans, which is an excellent development. This pile of welded sheet metal just needed some time to get used to the idea of being a coffee roaster!)
-> I have three non-functioning heliostats in the lab. Now that I have my shop back under one roof, I will be able to make some progress on this front. I have switched my plans away from the use of linear motors, and am going to experiment with worm-gear driven motors. I was initally looking at a classic "T-pole" design, or a "U" type yolk to hold the mirror. I am now entertaining the idea of a "∑" (sigma) shaped framework for holding each mirror and a pair of motor boxes. More on this later.
Having a glass of wine with the wife and reading about stirling engines. A wonderful Saturday evening!
Saturday, April 30, 2011
Saturday, April 23, 2011
Into the Sun
Rounding out the week bagging the last of the orders. It's going to take a feat of organization to organize our coffee shop and wholesale department so as to extricate myself from the day to day operations. I'm going to have to figure out how to put more time into this solar design project in the next month or two. Within three months, I will be working full-time on the R&D for the new heliostat motors.
I had 4 glass mirrors cut to scale and picked them up yesterday. The development plan looks something like this, in rough outline:
1) Build and Test motor
1000 cycles (mechanics durability)
Freezer test (low temp to -10˚F)
Oven test (Pueblo Summer temp up to 120˚F)
Bathtub test (water immersion)
2) Build and Test single Heliostat
Test accuracy & repeatability to 1/16˚ per axis
Car-Roof-Driving Test (aka wind-tunnel testing for high wind stowing capability)
Coffee-Shop-Ice Drop (aka testing under hail-impact conditions)
Sun Track to Target -I'll test it with an ad-hoc controller to target a spot in my back yard.
3) Build and test 5 Heliostats
Finalizing the control scheme electronics
Demonstrating a practical set-up procedure and calibration cycle
Demonstrate safety procedures and guidance corridores (mirrors must not shin in windows!)
4) 1/8 Scale array test: 25 Mirrors in my back yard and on-target
Test calibration procedure for 25 mirrors on wooden frame
Test targeting control system
Test all safety systems
Make last changes for mass-production of heliostats.
5) Manufacture remaining 200 heliostats, set up on bus garage in downtown Pueblo
(More detail to follow!)
I had 4 glass mirrors cut to scale and picked them up yesterday. The development plan looks something like this, in rough outline:
1) Build and Test motor
1000 cycles (mechanics durability)
Freezer test (low temp to -10˚F)
Oven test (Pueblo Summer temp up to 120˚F)
Bathtub test (water immersion)
2) Build and Test single Heliostat
Test accuracy & repeatability to 1/16˚ per axis
Car-Roof-Driving Test (aka wind-tunnel testing for high wind stowing capability)
Coffee-Shop-Ice Drop (aka testing under hail-impact conditions)
Sun Track to Target -I'll test it with an ad-hoc controller to target a spot in my back yard.
3) Build and test 5 Heliostats
Finalizing the control scheme electronics
Demonstrating a practical set-up procedure and calibration cycle
Demonstrate safety procedures and guidance corridores (mirrors must not shin in windows!)
4) 1/8 Scale array test: 25 Mirrors in my back yard and on-target
Test calibration procedure for 25 mirrors on wooden frame
Test targeting control system
Test all safety systems
Make last changes for mass-production of heliostats.
5) Manufacture remaining 200 heliostats, set up on bus garage in downtown Pueblo
(More detail to follow!)
Wednesday, April 20, 2011
R&D Parts Ordered
Ordered worm gears today for testing one kind of stepper motor assembly. (Ordered them from SDP/SI online. There is some stuff on smallparts.com.) I visited a metal yard here in Pueblo (Speken) and found that my preferred stepper motor slides snugly into 2x4" rectangular tube, so I bought a length of that. I then ordered a set of rectangular plastic inserts for the ends of the pipe. My plan is to create rigid steel housings for the motors from short sections of rectangular tubing. By simply using short sections of this tough construction material, I should be able to produce these things en-mass for low material cost and have them be rather strong. I will fit the worm gear, bearings, and potentially some driver circuitry into each rigid weatherproof box. Each mirror will get two of them.
I also ordered a set of four glass mirrors from Binswanger glass in Pueblo. It's costly to have a local place custom cut glass mirror. I'm going to have to price out delivery of 4x8' sheets of this stuff and build a table jig for cutting these things myself when it's time to go into full production. Anybody know where to buy 1/4" thick glass mirror in large sheets?
Got a dozen coffee orders wrapped up labeled & my wife Lindsay is dropping it at Fedex. Tomorrow we have some private label coffees to finish. I'll round out the week with a start of the formal design work for the heliostats. (How accurate do they actually need to be, how strong, how fast?)
I also ordered a set of four glass mirrors from Binswanger glass in Pueblo. It's costly to have a local place custom cut glass mirror. I'm going to have to price out delivery of 4x8' sheets of this stuff and build a table jig for cutting these things myself when it's time to go into full production. Anybody know where to buy 1/4" thick glass mirror in large sheets?
Got a dozen coffee orders wrapped up labeled & my wife Lindsay is dropping it at Fedex. Tomorrow we have some private label coffees to finish. I'll round out the week with a start of the formal design work for the heliostats. (How accurate do they actually need to be, how strong, how fast?)
Tuesday, April 19, 2011
In the Course of a Day
Today, I vacuumed out a coffee roaster, hefted 150 pound coffee bags, called 50 of our wholesale clients, discussed recycling with some regulars of the shop, called back all the folks on the answering machine, installed coffee brewers at City Diner in downtown pueblo, put a brewer in the new library at CSU Pueblo, made new labels and adverts in Illustrator, e-mailed some of our vendors, updated the video slide-show screens at the mall and downtown, and finally sat down to re-collect thoughts about solar power. It's amazing how busy Tuesdays can be! I feel like I saw a thousand or so people coming in and out of the coffee shop. I'm just sitting down with a catalog of gears to order a set of parts for a heliostat prototype. That is after all what I'm SUPPOSED to be doing -building a solar heat source for this roaster!
Despite some of these all-involving days at the coffee shop, progress is being made. There is a decent orderly way in which everything must be accomplished. The most immediate part of my outline looks something like this:
1.) Quantify all of the needed attributes and variables for these small heliostats. I need to formally set down how accurate these things need to be, how much force the motors must produce, and how much movement is permissible.
2.) Once that is done, I need to settle my year-long debate once and for all about my motors:
Linear Motor gearing vs. worm-gear motor gearing.
Linear motors are easy to build from low cost parts, but produce non-uniform movement of the mirror over their range. Worm gear motors produce true rotary motion with motor steps correlating directly to angular units of rotation over the whole range of movment. It is more difficult and expensive, however, to purchase/assemble worm gear drive systems. Especially considering that 220 heliostats means 440 of them! (vertical and horizontal movement for each mirror.)
Help me end this internal debate! (I'm ordering parts tonight and will build heliostats of each kind, keep track of the cost, and then test their functionality.)
Meanwhile, I think I need to get a cup of coffee!
Despite some of these all-involving days at the coffee shop, progress is being made. There is a decent orderly way in which everything must be accomplished. The most immediate part of my outline looks something like this:
1.) Quantify all of the needed attributes and variables for these small heliostats. I need to formally set down how accurate these things need to be, how much force the motors must produce, and how much movement is permissible.
2.) Once that is done, I need to settle my year-long debate once and for all about my motors:
Linear Motor gearing vs. worm-gear motor gearing.
Linear motors are easy to build from low cost parts, but produce non-uniform movement of the mirror over their range. Worm gear motors produce true rotary motion with motor steps correlating directly to angular units of rotation over the whole range of movment. It is more difficult and expensive, however, to purchase/assemble worm gear drive systems. Especially considering that 220 heliostats means 440 of them! (vertical and horizontal movement for each mirror.)
Help me end this internal debate! (I'm ordering parts tonight and will build heliostats of each kind, keep track of the cost, and then test their functionality.)
Meanwhile, I think I need to get a cup of coffee!
Sunday, April 17, 2011
New Coffee Roaster, New Project, New Future!
This week saw the first successful use of the brand-new coffee roaster machine, the Helios V. That is, the coffee-roasting part of it! I constructed it from sheet metal and ordered parts in a rented bus garage down the street. We have it set up in the back of our coffee shop on 3rd & Main in Pueblo, and we're running it through its paces. There are plenty of things bumping when they shouldn't, beans popping through where they don't belong, and smoke billowing out into the crowded cafe- but over all a success! It roasts evenly, all-be-it with heat from natural gas.
It always seems like the conclusion of one project is, in fact, the start of a new one! In this case, it is now finally time to start on the new concentrator. One year from today, this same roaster will be producing excellent coffee, and will be powered entirely with energy from the sun! (Hopefully with issues of the bumps, beans, and billowing resolved!)
Our previous solar coffee roaster is, in the mean time, going to be converted into a solar plastics recycling machine.
It's my first open-source technology project, and the first time anybody's made a focused and funded effort to create a full-scale commercial solar power tower and then place it into the public domain. As several close business advisers have warned me, it is a risk to give away what might be sold. It is my belief, though, that the potential gains justify the risk, and that open-source technologies are the paving stones and foundations of a newer brighter version of the future!
For periodic updates on these projects and all the adventures along the way, please stay tuned to this blog.
Sincerely,
David Hartkop
Owner & Inventor, Solar Roast Coffee & The Open Sun Project
It always seems like the conclusion of one project is, in fact, the start of a new one! In this case, it is now finally time to start on the new concentrator. One year from today, this same roaster will be producing excellent coffee, and will be powered entirely with energy from the sun! (Hopefully with issues of the bumps, beans, and billowing resolved!)
Our previous solar coffee roaster is, in the mean time, going to be converted into a solar plastics recycling machine.
It's my first open-source technology project, and the first time anybody's made a focused and funded effort to create a full-scale commercial solar power tower and then place it into the public domain. As several close business advisers have warned me, it is a risk to give away what might be sold. It is my belief, though, that the potential gains justify the risk, and that open-source technologies are the paving stones and foundations of a newer brighter version of the future!
For periodic updates on these projects and all the adventures along the way, please stay tuned to this blog.
Sincerely,
David Hartkop
Owner & Inventor, Solar Roast Coffee & The Open Sun Project
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