The concept

It's a box that contains a receipt printer and an interface with several buttons. A user would press a button that reflects their emotional state (happy, sad, anxious, etc.), then the machine prints out a more-or-less appropriate poem on a receipt printer, beautifully formatted and embellished with simple artwork.

It could be occasionally repurposed for certain themes, like Pride Month to print out queer poems.

I want to place it someplace public and well-trafficked, like Dolores Park or on Castro Street.

Feedback

I like poetry. The idea of a (free) vending machine that gives me a poem to uplift my day excites me. But I wonder if this appeals to others enough to be worth fully realizing. I don't want to spend time and money building something that'll go totally unloved.

Also curious about anti-vandalism measures or ideas. I'm sure some jerk will try graffiti-ing it or peeing on it.

Lastly, anyone interested in collaborating?

A while ago I mentioned I was going to attempt making a knife for the first time. Well, I did.

Apologies in advance for there not being many photos of the process - steel is really messy to work with so I mostly kept my phone safely out of the way. I'll try to get more pictures next time, although there are plenty of videos and picture tutorials around if people are super interested in the process. I shall endeavour to describe what I did in text, however.

I started out with a bar of 01 tool steel (wiki) which I cut into a rough knife blank. This I then hit with a ball hammer a load of times to get some texture. Then I used a belt grinder to put a bevel on the edge side, although only enough to thin the knife down to roughly the right shape, not actually sharp. Once that and a few other minor shaping tasks were done, it was time to heat treat it.

Heat treating changes the structure of the metal to make it harder. Hard steel will hold an edge longer, but it does make it much more difficult to work, hence doing most of the shaping before heat treating. To harden steel you need to heat it to a particular temperature, which depends on the exact alloy being used but 'bright orange' is close enough. Fun fact - when steel gets to it's 'critical' temperature, it stops being magnetic, so that's another way you can test it. The steel is then quenched, this one in oil, which makes it hard.

Hardened steel is very brittle so it's usually tempered after hardening. For 01 steel that means putting it in an oven at 160-200C for a couple of hours. You lose some hardness but you gain back some toughness and flexibility.

After tempering, cleaning, polishing, polishing and so much polishing. Steel is so dirty and difficult to work with compared to the silver, gold and copper I'm more used to. But eventually, and after glueing and bolting a sycamore wood handle on, then giving it a final sharpen on my wetstone, I had a knife.

It is a Japanese-style Nakiri knife. Usually used for cutting vegetables, it's really nice to use. Lightweight and agile, the balance is nice and it's comfortable in my hand. It's not perfect and there are a few things I'd do differently but I can see myself using this on a daily basis. More pictures

I have already laid out and started shaping my next knife, which will be a slightly more complicated bunka knife

Any questions, please just ask and I'll do my best to answer.

Someone recently asked me to replace the battery in their old iPod, and I found myself wondering what I should do with the old battery. It still works, but has less capacity than when it was new. So I looked around my workshop and found some of these surface mount LEDs and decided to test the limits of my soldering skills and make a flashlight out of them.

These LEDs are very hard to solder, since they're surface-mount and the pads are on the bottom of the LED. They were never meant to be soldered by hand, but rather placed by machine onto a specific amount of solder paste, which is then baked in a fancy oven at very specific temperatures for very specific times. To solder these by hand, you need to create a liquid puddle of solder and sorta float the LED on top, while being careful to not short the pads which are very close together as well as not overheating the LED. The temperature the plastic melts at seems to be only a few degrees higher than the solder melts at.

I wired up 5 of the LEDs in parallel, each with its own 6.8ohm resistor wired in series with the LED. This should limit the current to 150mA per LED. I hot glued this in place, as well as a lithium battery charging circuit I got off ebay for a dollar. Here's one such listing.

I slapped on a pushbutton, and Bob's your uncle! It worked first try!

Here's a blurry picture of the finished product. I'm pretty proud of how it came out, considering how tiny and fiddly the soldering was. And, I think I'll actually get some use out of it too. The battery ought to last at least an hour of runtime, and the thing is seriously bright.

Anyone here into electronics as a hobby?

Edit: Better-ish pic: https://i.imgur.com/Kxqy1jg.jpg

^{No potatoes were harmed in the making of this photo.}