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.

Some days ago I came back home to visit my parents during these holidays.

Yesterday evening, while we were watching a movie, nature called and I had to go to the bathroom. Because I'm a lazy bozo and it is closer to the living room, I did what no man should ever do - I used my parents' bathroom.

Stumbling in the dark in this unfamiliar place I had no right being in, I clumsily bumped on the towel rack (an old 80s coat hanger looking thing) and to my horror, managed to snap one of its plastic arms off.

Because it's a relic of its time, and perhaps because the bathroom is a sacred personal space which should never be altered if not for strictly necessary reasons, mom and pops were upset.

I felt like shit, an outcast whose madness lead an entire family to despair and misfortune while trying to save himself literally a handful of pitiful steps.

But a shining beacon of hope came from a fading memory, one which sounded utterly absurd, yet in times of desperation still came out as somehow plausible.

"Just use baking soda and Loctite forehead"; this had been uttered from a German friend of mine while he had been admiring the broken mess that is my duct taped ps4 controller some time ago. Was it a joke? Was it a serious suggestion? German humor is often lost in translation...

Still, I had to give it a go. I had to try something. And this morning an attempt was made.

I'm still feeling ecstatic. Never have I hever felt this good about a DIY tryout. I can confirm that baking soda is an incredible catalyst for super glue; the result while somewhat sloppy-looking is rock solid.

Pops couldn't believe his eyes when he saw his good ol' towel rack hanger thing stoically standing where it always did, in its rightful place, with no defects at all.

Thank you baking soda and super glue, you saved Christmas.

To all of you whose plastics need some fixing, remember this combo and give it a go - it will save you as well.

Any other similar hacks that you might want to share are very much appreciated.

TL;DR
Baking soda and regular superglue are incredible for fixing plastics.

Edit: forgot to put tags in post. Apologies.

I'm looking to get a couple of remote controlled dimmer sockets for a quite specific use case (heat lamps in a tortoise enclosure), and I'd like to control them directly from a Raspberry Pi. I've found a couple of decent looking fairly generic options - examples from Trust and TKB - and there seem to be several appropriate radio modules, either USB or GPIO.

Detecting and pairing with devices seems (hopefully) straightforward. My sticking point is trying to figure out how standardised the actual messaging is; there seem to be several brands of hub and device that can be used interchangeably, but a few that can't. In my case, of course, the RasPi will be taking the position of the hub and speaking to the devices directly.

I'm having trouble finding reliable info on whether a command like "dim to 70%", or "read output power" will be the same across all devices, whether it will follow some kind of standard but it may be one of several competing formats, or whether it's completely proprietary.

Any insight on how easy it is to programatically talk to these things would be very much appreciated!

I built a basic panel out of some boards left over from another project. I'd like to use this as a desktop surface just laid on top of some filing cabinets. I'm wondering what the best way to finish this would be? I don't think I want to paint and I'm ok with some light staining but I don't have any experience with sealing or whatever I would want to do to help preserve the surface. It would have typical office items on it (keyboard, mouse, monitor, paper, pens, etc.).

I am currently trying to learn how to fix things myself by learning how to solder and fix things like that. I also want to DIY some things for quite some time.

My current project is working through the book Make:Electronics , I bought it at humblebundle some years ago. Yesterday I powered a led via a power outlet for the first time, by connecting it to a cut off USB cable. I'll share a picture of the abomination later.

So: what have you built at home? What are you building? What are you planning to build?

Tried this a few months ago, wanted to see if anyone was interested in sharing.

Just curious if anyone has been working on any music projects they'd want to share? Maybe even local / independent artists you feel strongly about? Post them links!

The ErgoDox has been out for a few years now and spawned many, many new designs based off it. My question is how would you improve it? I've been trying to answer this question for a few weeks now and would like to know what the community thinks. What is important in a keyboard for you?

I've thrown my hat into the ring with Gergo which I think comes close. It uses SMD components, reducing the overall size and cost of the board, Removes the ProMicro for a TQFP Atmega32u4, moves the paddles in a tiny bit and removes the extra keys from the thumb cluster. It's meant to be used without a case (using rubbered standoffs to keep it off the desk/surface) and the back has some pretty designs. The hardest part for me to justify was loping off the number row, but seeing as many layouts use a modifier and the right hand pad as a ortho numpad I went with it. Worst case the default layout will have paddle + top row give numbers. In addition, for occasional mouse users, I designed a trackball that fits inside of a 1u key and can be mounted on the right hand side of the board (or a regular key if wanted). The idea being for small movements you have something other then QMKs mouse keys to work with. I've gone into a bit more detail on my blog on the design considerations

The main thing I tried to optimize with Gergo was cost. Ergo keyboards need not be expensive and I think the price point on this board drives it home. With a cheap set of caps off Amazon and some Cherry clones, this board can be put together for under 100$ shipping included. Compared to a ErgoDox EZ with a starting price of 250$ before keys or shipping, I think I've done a decent job.

As keyboards are highly personal devices, what do you look for in a keyboard?

I just got my /dev/tty blanks in from Massdrop and I an thinking of dying them to match my current ABS colorway.

I have looked at the guide and I think I am able to do all that, but I am wondering what kind of look I am going to/can get by dying the gray and red caps?

I assume the gray caps would just yield a slightly darker color, but I am curious if I can get an interesting shade of brown by dying the red keycaps with some other color (or just more brown?)

Any hints on dying the colored caps or dying PBT in general are appreciated.

I added a bidet attachment.

Installation went fine.

When I tested the bidet, it kind of went like this...

https://tataandhoward.com/wp-content/uploads/2015/04/Drinking_out_of_a_toilet_fountain_at_the_Exploratorium.jpg

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.}