kedikedi

Experiment results: my grinder was able to cut 18mm steel rod in about 20 seconds.

For completeness sake, I used a machinable steel rod, turned to 18mm. For cutting I used a Makita 18V grinder with a 125mm disc (I had a partially used disc. A full disc would cut it faster) and with a full battery (it cuts slightly slower as battery runs out).

True, bolt cutters are useless on a thick u-lock but I am not sure about the cutting disc taking too long. I’ll try to find some* 18mm steel and try to cut it with my 18V grinder. I’ll comment the result here :)

*it may be a different grade steel than a lock steel

I just got mine about a week ago and I’m totally in love with it. So far I can see that the bike can replace the car for most of the time (exceptions are bad weather and when I need to carry things) and my bike route is definitely more interesting than my car route.

The only problem I see is that bikes are also very easy to be stolen and the police here (Finland) doesn’t seem to do much about it.

Very interesting! I thought the indicator stalk would be very intuitive because it’s just the same as the steering movement: imitating a right turn with your pinky sticking out initiates a right indication.

The light controls still confuse me and I’ve been driving for 10+ years now. It is also slightly different in different cats too! Sometimes you pull hard, sometimes you push, and I guess sometimes you twist.

Maybe a bit anectodal, but the reason is that diesel emission devices are more complex and more prone to failure or require more maintenance (perceived as annoyance by the user).

Here is more explanation: with the diesel emission devices, you are trying to control soot and NOx gasses. For example the EGR (exhaust gas recirculation) system reintroduces a bit of exhaust gas back to intake to reduce combustion temperature to reduce NOx gasses. However, this means that you are introducing sooty gas back to the intake, where it messes with other stuff like swirl flaps.

Swirl flaps are there to create a small tornado inside the cylinder for more efficient mixing and burning. But these are mechanical flaps and, in the best case, they stop working when they soot up. In the worst case, however, they go inside the cylinder and cause catastropic damage, requiring an engine rebuild/replacement.

Then another emission device for diesels is the particle filter. This is a very fine filter to catch soot exiting the exhaust. The engine puts a bit more fuel every now and then to burn them off properly. But the engine needs to run under a certain load and operating temperature for this operation to succeed, and if not, it gets permanently blocked and you need to visit a garage to force it or to have it cleaned/replaced. This happens if you only drive short distances and never let the engine to warm up, or if you idle for too long, or if you always drive in stop and go traffic. And sometimes, the filter collects ash instead of soot and that can't be burned off. This happens when you use incorrect sort of oil in a modern diesel car or if the fuel is bad. The only cure is cleaning or replacement of the filter.

Then you have another emission device: the ammonia. Newer cars spray a bit of ammonia (AdBlue) every now and then on the exhaust gasses to reduce NOx emmisions. This adds one more thing to refill every now and then and the car reduces power if you don't comply.

Now compare this to the gasoline car emission device: the catalyst. This one fails if you overheat it, or if it goes too old by age. The overheating happens if the combustion is too rich (too much fuel for the amount of air) for a long time but the engine controller prevents it anyway. Catalyst is there to burn any unburnt fuel and turn carbon monoxide into carbon dioxide.

Some newer cars also have EGR in them like a diesel car AFAIK, but I am not aware of the relevant failures of that bit.

That’s how it is done in, for example, boats as well as other places where you want to extract heat to a lake or to a sea.

You have your typical nice and clean coolant circuit that circulates through the engine, and then through a heat exchanger, you give that heat out to the sea water. This way the heat exchanger becomes somewhat sacrificial and you replace only that if it gets destroyed. And you don’t have to harden every single surface for sea water and all the creatures that come with it.

Interesting stuff! I make chocolate moulds out of 3D printed shapes and I’ve been struggling with solidifying the molten chocolate. After reading a bit, it seems like I’m ruining the crystalline structure of the material by overheating it. Funny how it sounds like metallurgy but is just chocolate :)

I think this explains why my old computer was so confused about languages. The windows apps were in Finnish, system settings etc. were in English. Then some parts of Google stuff were in Turkish, some in Finnish, and some others were in English. Every now and then some random app would appear and surprise me in Turkish. It was truly impossible to tell what language would appear after each click.

It was originally running windows 7 with English as the system language. Some software were installed while I was in Turkey, some (including windows 10 upgrade) were installed after I moved to Finland. Now I’m learning that my computer couldn’t handle this gracefully :)

Sound is one thing but also think of the dust, especially if you’re planning to machine pcb at your home. That’s not good stuff.

But speaking of sound, some of it comes from the spindle. The faster it turns, the more noise it makes (usually). I was using a dremel as my spindle some time ago and it was veery noisy. Then I tried another machine that had a bigger spindle, that one was much quieter.

Then there’s the sound of the material being processed. The cutting bit hits the material at spindle_speed*flute_count Hz. This also creates hell of a vibration.

So you need to do two things: dampen the vibrations, and block the radiated noise. Plus you want to make sure you have some sort of dust control.

This sounds very similar to how one can do online dating

Well, it isn't an integral part of the cars or anything. It is basically a chonky powerbank that can jumpstart a car.

I've got a question; if it is ok to lie in these reports, why do they even exist? I thought these reports were there as a way to introduce client capabilities so that the server can serve the right content.

Disclaimer: This is a genuine question. I'm a hardware guy and I don't know how web works nowadays.

+1 This is not just for apps, it also happens with websites. I am not a web guy, so I don't know the jargon but web pages keep changing even after they are done. I tap on something but it just adds another element there and I end up tapping on something else since everything shifts

Ah, I was working on a similar idea when I was in upper secondary school. But I was unable to do get what I want with my very limited electronics knowledge back then :)

I was thinking of storing and playing the data in an analog way, pretty much like a regular compact cassette meant for audio. I thought it was a better idea after seeing audio casettes can store 60/90 minutes of audio but they can hold only very little digital data (I had a commodore that I found in my grandma's cellar and those casettes were my unit of measure)

This list looks cool! For some reason HN is too much focused on software and usually there isn't much of anything hardware.

I also enjoy making robots just for the fun of it. Here are some examples from my side:

- Bebe: www.youtube.com/watch?v=bViFrTQ-DQ0 Bebe is my lovechild. He fulfills my paternal instincts and the best part of the day is when he runs at me affectionately with all his 28 legs. Unfortunately, Bebe is a naughty boi and he broke half of his legs when he fell from a beer pong table. He can't run nowadays.

- micro InvaderBot: www.youtube.com/watch?v=G3a9dcDeQbc micro InvaderBot is the smaller version of InvaderBot. Not much of it is known, but it is believed that it has escaped from Dvergar facilities during Robot Uprising.

robotuprising.fi This is a story based hackathon that we used to organize annually. I don't know how it will go this year due to coronavirus, but we keep the fingers crossed :)

I would consider myself good with following direction signs and being in traffic in general. However, I find that roundabout very confusing.

What makes it confusing is, I think, the overhead signs in the roundabout. It would be easier without them. Because the arrows pointing up also points towards the incorrect exit at the same time due to the round nature of the road :)