OK, we’ve all been there. We’ve bought one of those little butane torches (perhaps for creme brulee, perhaps for heat-shrink tubing). And then we’ve discovered price discrimination. You see, it costs $7 for 150g of ‘lighter refill butane’ but a 3-pack of 227g containers of ‘stove propane’ is $10. Wait a minute, about 3x as much for ‘lighter propane’. Is this not exactly the same product? Compressed gas? Yes it is. The only difference is the diameter of the refill hole.
Am I going to let big-butane stick it to me? No way! I have a 3D printer, it seems like this would be the perfect opportunity to make something that was two cylinders stacked on each other, which, in the greater scheme of 3D modelling is not that hard.
OK lets give it a go. First we’ll try PLA (photo below). OK, well, this works as a proof of concept, but the tip is a bit too soft, and there is some leakage. Still, on the first test the torch lit (and so did the sink and my arms. Ooops, lets turn on the exhaust fan, burnt hair is pretty stinky…. Its no stinky cat… but… definitely not the smell of success I was looking for).
OK, lets give this a go w/ ABS. Fortunately my printer is dual extruder so just switch temperatures and light up the other side (I also used 100% infill). For kicks I’ll also print one at 95%, and one at 98% size. And bingo, we are in!
OK this was brought to my attention by a friend. I won’t mention his name, his love of swiss-chalet sauce and avocado, or the large south-american country from which he hails. But he was certainly in the process of backing this kickstarter.
When I was a kid, one of the best (in syndication) shows was Get Smart. And it had this device, the cone of silence. Max and Chief would get in it and talk freely (rather than using the shoe-phone which chaos could certainly hear). Nifty.
Well, that science fiction has now come true. You can order your very own Hushme. And its certainly a problem you have. You’re out and about. The phone rings. Its that $B deal you have been negotiating. Or maybe its the caterer calling to ask about what type of hotdogs to order for your wife’s surprise birthday party. Either way, you don’t want someone overhearing.
Why leave the room like a plebe when you can go shields-up and talk right there? Well, watch the video, and then take out your cheque book. $189 later and you can have one. But wait, you really need all your friends to have one too, so may was well get the friend-pack for $359 (which is two). Wait, you want *all* your friends? Oh, that’s still the two-pack. Sorry about that. Don’t worry, you won’t look stupid wearing this to the club.
At any rate, watch the video below. At 40seconds in, it all becomes clear. This is nearly certainty the number one problem you didn’t know you had.
Many years ago our family went on a camping trip, some where near Sand Banks in Prince Edward County I believe. At the time we owned a giant middle-aged Cadillac Coupe deVille (you know the kind with doors that were as long as the eye could see, and whacked every other car in the parking lot?), and you can see it packed to the gills with the camping gear needed (including a case of Labatt’s finest stubbies). We went on this trip with friends of my parents, who did not have children, leaving my brother and I as somewhat the odd ones out.
Now, this friend of our parents, mike, decided that my brother and I could entertain ourselves if he created the right environment. He took us to the beach (which was right beside our campsite), and to a picnic table there. I remember him explaining how people would sit at tables on the beach, and that money would fall out of their pockets.
To demonstrate, he dug around in the sand a bit with his hands, and, lo and behold, found a quarter and a dime. (which i later learned was a plant!)
Now, my brother and I (at right, i’m the one closest to the water) were very intrigued by this turn of events, and spent the rest of the weekend excavating that beach for the fortune we knew to be present.
My brother and I laboured away for hours while probably that case of stubbies grew empty and the adults chuckled at the gullibility of the younger humanity. We were determined to become beach-coin millionaires.
And you see, the beauty of this scheme, Machiavellian though it was, it had its root in something that was believable, and a starter-fact was demonstrated. Once that happened, we disconnected our doubt-engines and ran with it.
And this is how many security scams work today. A small amount of believable information is presented to you. Once you stop doubting the first thing, you stop doubting all things, and next thing you know you are in an apple store buying $10K in iTunes gift cards and arguing with the clerk who is adamant that those are not possibly going to be used to pay down your taxes or get your friend out of jail etc. You bought the story, and now you are trenching a beach in search of lost quarters, the doubt is a million miles behind you.
So next time you receive some email that has something believable (your address? bank balance? friends name?) but is a bit suspicious, keep the doubt-engine in gear, and think of me hunting for beach bucks, don’t be that person who falls for the spear-phishing.
PS, back to the pictures. That Cadillac, well, it had a fake fur interior and smelled like wet dog and acrylic. It was near the end of the tail-fin craze (read “How the Cadillac Got its Fins” for some truly great business stories). It had no seat belts in the back seat, and cornered like a waterbed on a red wagon. But that trunk was truly large! I don’t recall if we had the 472 (7.7L) engine or the 500 (8.2L) engine. But i’m sure that whichever it was, coupled w/ that 3-speed automatic it got fantastic gas mileage as it hauled its 5400lbs (unladen weight) around.
OK so I spent a day watching a rocket launch this week. And I took a lot of pictures on a mobile device. And I was roaming. So, am I going to be bankrupt? What will happen?
First, how well did it work. In short, not very. Although I had full signal strength on LTE+, and the downstream (download) seemed ok. the upstream (upload) just got nothing through. It would retransmit again and again, timeout, retry, etc.
So, do i get charged for this? You betcha! Lets look at my graph. The nearly vertical line in bandwidth usage (which I showed the red start/end of) is the ~10 hour period I was @ Kennedy Space Centre. It tried to upload 1.86GB of data (and succeeded on about 5 pictures or about 30MB). So the efficiency was ~0%.
What happens? Well, the mobile network is allocating time slots for upstream to the various users. And there are not enough. So my app (Google Photos) is using HTTP(s) to POST these images to a server. And, since there is not enough upstream, it times out and tries again. And again. In doing so, its actually making things worse. It sends the first bit of a file, fails to get acknowledgement, so it sends it again. This uses 2x the timeslots/bandwidth, which then takes that away from someone else, that happens to them, and the whole thing goes into congestive collapse.
So my phone, which is capable of Cat 15 (800Mbps) of LTE+, gets nothing through, and tries infinitely hard. Its goodput is near zero. So everyone loses. The capacity is consumed, I pay, I get no experience for it, and other users lose this opportunity.
There are some queuing algorithms (e.g. see CoDel) which try to resolve this. There are also some transports (e.g. LEDBAT) which seek to solve this issue.
Note that its probable here that the congestion was based on the number of stations more so than the bandwidth they are using.
ps, still enjoyed the launch!
pps ammended w/ the usage link from the carrier. I cannot make head nor tail of the timeline tho.