This applies for example when you want to add a photovoltaics installation to your campervan, expedition vehicle, garden hut, off-grid house or similar. For having enough electricity year-round from photovoltaics alone, battery size and module size have to be properly dimensioned.

The best tool I found for this is the European Commission JRC's PV potential estimation utility. There, use the last tab "Stand-alone PV".

Note that that the tilting angle of the solar panels is important in winter. Differences of up to ca. 30° from the optimum have no large effect, but above that they get quite important. So having an angle of 0° (flat panels) while you should have an angle of 74° (Germany in winter for example) means you get only about 25% of the power you would get at a 74° angle. You can calculate the exact numbers for this with the SunAngle calculator.

Statistical Design Meeting and Workshop in Strasbourg, 2013-03-25 to -26.

We worked quite intensively and at the same time, everybody seemed to enjoy it – that's how I like work to be 🙂 Thanks to everybody involved!

All images on this page licenced under CC BY-SA 3.0 Unported, or at your option, any later version.
Please attribute to "Matt" and this page's URL (that is, do not use my real name).

Sorry for the bad image quality. My real cam broke down and I did not get around yet to repair it …

On a nice evening with a friend in Málaga this October, we developed this idea for political street art. (We were kinda oversugared from the best icecream in town … it explains something, doesn’t it? 😀 ) Initially we wanted to cut our own “Espere Revolución” signs and install them over the city’s normal push-button boxes for pedestrian traffic lights. But for now, it’s a mockup.

Political street art: Espere Revolución (small excerpt size 1024×768)

Political street art: Espere Revolución (large size 2048×1365)

The pedestrian traffic lights sign in the image reads: “Touch the button”. Then you push it, and it says then: “Expect revolution.” (It’s normally “Espere Verde” – expect green light. Plus a standing person with both hands down.)

Licence: Creative Commons Attribution Non-Commercial Share Alike 2.0

Credits: The original image was created by flickr.com user david buedo and published as flickr image 6949945397 under a Creative Commons Attribution Non-Commercial Share Alike 2.0 licence. Thank you!

Modifiable version: Just tell me in the comments if somebody wants the GIMP .xcf.bz2 file of this, with layers for easy modification to make other signs as well.

It seems like this:

  • The lashing capacity LC according to the norm (EN 12195-2) means the maximum allowed force on the strap in straight pull.
  • When buying lashing straps, you might get an additional second LC measure that is double of the normal LC. This is the lashing capacity in round pull.
  • Why is round pull LC double that of straight pull LC? Think of an application where you connect two points have 180° deflection of the lashing strap (around a tube or similar) at each, in effect making the lashing strap go a full round. A model for this is a small set of pulleys with two barrels and double string. Each of the strings of the one lashing strap (one going forward, the other going back) now has only to bear half of the force between these two points that you pull together, which doubles the lashing capacity compared to straight pull. And as in a pulley system, the force on the belt is the same everywhere as it can distribute evenly, so the part in the 180° deflection point also bears just half the load of the full system.
  • To make the confusion complete, there is a code concerning straight line seams on the lashing straps. They are called “ton lines” (German: Tonnenstreifen) and people think that they indicate: one stripe per 1000 daN lashing capacity in round pull (not in straight pull). But I have yet to see the norm text for that and could not find any source (Hey regulators! You still don’t have these as open content? C’m on, nobody wants to pay 224 USD for the EN 12195-2). In case of lifting loops, they are called “load bearing capacity stripes” (German: Tragfähigkeitsstreifen) and there, indeed, one stripe seems to mean 1000 kg of capacity, but in direct pull.

See also another (German) site with explanations of the lashing strap norm’s abbreviations (LC, HF, SHF, STF, BF, BFmin).

Before using information in this text for security critical applications, check the facts for yourself. I do not take any responsibility!

Currently I'm building the first parts of my truck's furniture system. The system is based on gridbeam, an awesome simple DIY construction system from the 1970's. Practically this means: boxes, room partitioning walls, shelves, desks etc. all use the same sheet material and connector elements and with the same compatible hole pattern, so one can build everything from the same set of elements, and can reuse the parts from a no longer needed object to build something else. Or reconfigure the furniture according to current demands, using an inbus wrench.

I'm starting to build my furniture with some simple storage boxes that will be secured to the wall in several layers, yielding a big 70 cm deep shelf for general storage. Both this box system and gridbeam itself are detailed in the interface specs part of the EarthOS document. But here's a quick overview of my design choices:

  • Compatible with ISO pallets. Size is 700 x 350 x 350 mm, together with with handles and corner elements etc. up to 800 x 400 x 400 mm is allowed.
  • Same size walls. The basic wall size is 350 x 350 mm, and in this case I build double-depth boxes, so some walls are 700 x 350 mm. These larger walls could also be created by combining two of the smaller walls with aluminum sheet metal connectors; and likewise for even larger boxes. To allow creating a box from just same-sized walls, the walls have 45°  beveled edges.
  • 50 mm gridbeam system. This means, all sheet material has a 50 x 50 mm hole pattern starting 25 mm from all edges (holes are here only around the edges, more holes can be added on demand). Holes in boards are 8.5 mm for M8 bolts, but in the case of boxes fitting for M6 sleeve nuts. Holes in aluminum connector elements are 6.5 mm for M6 bolts.
  • Modified hammer-in nuts. I really had a problem finding reasonably priced sleeve nuts for going into the board holes – I'm just not paying 1 EUR and more for one lathed sleeve nut, that would be 55 EUR per box for 'em alone. So I finally tried ordinary M6x8 hammer-in nuts with their four spikes, and just cut away the spikes with tinsnips. By letting 1 mm of the spikes in place, these nuts will not even free-rotate when at the loose end and turning a bolt into them. They have enough grip in wood that way, while the sheet wood and the nut is still reusable infinitely (which was not the case with the spikes in place).
  • Bolts used. Currently M6 x 13 stainless steel (A2-70) bolts with inbus head. Used together with a washer to secure the bolt against loosing and to better distribute the force to the (relatively soft) aluminium sheet metal.
  • Apt for cheap and salvage materials. I'm currently creating the corner elements from simple aluminum sheet metal that I had lying around and that can be had from the local recycling yard nearly for free (as in free beer, not as in FREE BEER). Using 50 x 50 mm and 100 x 50 mm aluminum L-profile is also possible and looks better (examples in second picture) but is of course more expensive and less autarkic. Also, one can use many different types of material for the box walls: any thickness will fit because of the beveled edges and because the box's outer measures are standardized, not the inner ones.

Writing this I realize how trivially simple this design is. Yet the simple ones are hard, for whatever reason. I had developed thoughts for the box system over months, and even started building one variant which was way too complex and too expensive. The current variant emerged after some great, inspiring discussions with my Dad on the matter. (I should know where my hacker genes come from ;))

And here are some pictures of the current progress with the boxes. (Some parts are obviously still missing: corner elements for stacking, handles, a flap, locking bolts.)

See this unrelated item in the media gallery? It's a rare Thermoflash fluid-heated jacket that I got as a bargain on eBay. Can keep everybody warm through German winter. Yep, really everybody 😉 Normally used on motorbikes and connected to the engine's cooling circuit via a heat exchanger and digital temperature control.

Oops, no wheels :) But we're checking the brakes.

Here’s a little page with images and videos from the make-a-truck-my-home project that I have going on since … well, too long already 🙂 Enjoy!

A video of the raw box body the morning after we transported it home:

And a video of driving the truck to the petrol station immediately after buying it:

 

Just posted a short bio on my Edgeryders profile and thought it’s quite funny, so I also post it here. I made the experience that putting your life “as it is”, without elevating yourself, makes for the most cool and readable presentation style (think Cullman Liquidation – they inspired me). Self-appraisal just puts you on par with boring old commercials, but telling them how it is makes people think “Wow, he went through that all and is still an upright man. Respect!” You can also profit yourself from writing it down like that: when reading again and feeling your life reads strange enough to make for a movie, it will help you in all that suffering ;-.)

Hope you have as much fun reading as I have living this 😀

CS studies. In my computer science, I pretty much only appeared at exams (yea I know, quite solitary learning style – distance learning would be my thing, but it wasn’t widespread back then). After the finals two of my profs offered me a PhD option. Yet I declined, even without knowing what to do instead and at all. But some narrow research stuff of their choosing very probably wasn’t it.

On knowing not. So not knowing what to choose next, I simply jobbed part-time as a truck driver for a friend’s company, until after a year he lost the whole trucking contract. By then, living on just a minimal income with plenty of time to think about life, I had finally found what to do with it: “I am here to find out why I’m here”. There was no way for me to circumnavigate the meaning-of-life question. So instead it became my first passion. Here we go.

Umh, why do you call it work “life”? But even the tech monk that I was now needed to earn a living. Continuing extreme aversion to 9-5 nonsensical work left me with few options. I becamse self-employed, avoiding the 9-5, but the nonsense sticked: For a laundry shop, I built digital video surveillance that made the police happy (yikes!). For another customer, the task was to take free software captive by bundling it as a for-sale extension to their app. And I had my fair share of precarious freelance work when some fixed-price web dev projects turned out five times the original effort and got paid years late. I left freelancing in utmost frustration and now work as hopeful co-founder of a collaborative consumption startup (mintybox.com).

Heureka (thank you, economic crisis)! So this is how I stumbled into worklife, while around me, the global economic crisis was going rampant. Together, these ingredients made me think hard and I became obsessed with how to design a society that just works, and the tech to run it sustainably. That’s now my second passion and very much a work in progress, called “EarthOS”. It’s a system orchestrating all the existing free & open ideas so that all aspects of life are served by free, open, P2P tech and services only – see the EarthOS framework and equipment documents. Of course everybody here thinks I’m this crazy utopian 😀

The nomad. And I’m also getting practical with EarthOS stuff from equipment levels 1 and 2, making it the interior for my … well, home. It happened to be cheap, just what I needed at that time: 500 bucks for that freezer box body from a torn-down truck. And a year after, I found a 4×4 firefighter truck chassis from 1968 and bolted the box body to the truck. This combo is street legal now (yay!) and I’m eager to move in, to get going with my meaning-of-life expeditions and further EarthOS prototyping. (And hey, I will always be happy to stop at the door of amazing people. Welcome to drop me a line!)