mechanical_gifs

How a combination lock works, with transparent model seen from the back

This style of lock is commonly used on bank vaults and safes. A clever part of the design is that, while the dial is being turned, the orange disk keeps the fence raised up, so there is absolutely no way to feel or hear when the gates are traveling underneath. The alignment of the gates is tested only once per revolution, making this kind of lock quite difficult to pick.

Laser cutter files to make one are at https://www.thingiverse.com/theodoregray/collections/mechanicalgifs and kits of pre-cut parts are at https://mechanicalgifs.com

I have a fan! I have a fan! Look everyone, I have a fan! Uh, I mean, thank you, and I'm glad you enjoy my work.

Whoa, is that THE Theodore Gray posting oc to our little backwater subreddit? I means that's pretty cool. Your column was my favorite part of pop sci.

It took me forever to realize that the blue pins on the discs were stacking up and causing it to turn the last wheel. So now I finally understand why you have so many rotations to get each specific number and why you have to start over if it's turned to far. Thanks for posting this it was very helpful and informative.

I'm already coming up with great new uses for my laser engraver

I'm already coming up with great new uses for my laser engraver

Now staple it to a tree.

I turned away from the screen when the gif started because I was worried about my eyes. I’m not smart.

You need to be engraving images of Jesus/Mary and then lightly toasting it.

Sell them on Ebay.

After lasering on a Trebuchet

Drilling a square hole with radiused corners

Wow, it instantly makes a square pattern, it doesn't even need to cut the first section!

New drill bit exclusively from Mazda.

I'm curious what materials this can be used on. Could be really effective on wood, but looks like it's gonna be tough on steel.

I bet that would be extremely hard to hold center.

Just a little off the tip

Just a little off the tip

Aw man you cut off the finishing pass

From what I remember from high school, you can't cut off more than a sliver at a time without damaging the blade.

Yep! 

How much material you can remove in one pass varies a lot depending on a TON of factors. The RPM, the diameter (which added up give you surface feet per minute which is another story altogether), the material itself, the tooling that you're using (both the material of the insert, the shape of the insert, the corner radius, the angle, etc), how far the material is sticking out of the collet, even the rigidity of the machine all come into play.

The tooling isn't really a 'blade', it's an 'Insert', specifically a 55 degree carbide insert, probably a DNMG. 

But yeah, you can only remove so much with each pass before any number of bad things happen. You also have to remove enough that you don't get a back-and-forth springy skipping effect known as chatter. 

Feeds and speeds are a bitch. 

(I'm a guy who turns metal into smaller pieces of metal for a living)

Yep!

How much material you can varies a lot depending on a TON of factors. The RPM, the diameter (which added up give you surface feet per minute which is another story altogether), the material itself, the tooling that you're using (both the material of the insert, the shape of the insert, the corner radius, the angle, etc), how far the material is sticking out of the collet, even the rigidity of the machine all come into play.

The tooling isn't really a 'blade', it's an 'Insert', specifically a 55 degree carbide insert, probably a DNMG.

But yeah, you can only remove so much with each pass before any number of bad things happen. You also have to remove enough that you don't get a back-and-forth springy skipping effect known as chatter.

Feeds and speeds are a bitch.

(I'm a guy who turns metal into smaller pieces of metal for a living)

Why didn't it just start at the tip and gradually shave down the round tip?

A fire piston can generate enough heat from the rapid compression of air to ignite a piece of cotton

A fire piston can generate enough heat from the rapid compression of air to ignite a piece of cotton

Isn't this how a diesel engine basically works?

it do

Somewhat related, if you dump superglue on clean cotton, it'll spontaneously ignite.

Yes, opposed to an Otto (gasoline) cycle a diesel cycle makes use of a fuel injector and relies on the rapid compression to ignite the diesel and not a spark plug.

8 digit version of the segment clock

I am extremely disappointed that they didn't make it say 'boobies'.

Paging /sub/highqualitygifs

I'd buy that for a dollar.

where can i get some of these?

This clock displays its numbers using panelled segments

So satisfying

Probably noisy as hell.

Probably worth it anyway.

I'm picturing a massive one on the wall of my office as a dual-purpose clock and countdown timer. Someone comes into the office, and I tell them they have 1 minute of my time, press a button, and the clock flicks quickly to "1:00". One more press of the button, and it starts counting down loudly second by second almost drowning them out as I stare waiting for them to talk.

Bonus: It would be awesome if it could run in loud and quiet modes, so I could flip a switch to ask my questions after they were forced to yell over the ticking.

My thought exactly, like how often have we all watched seconds tick by, but something about this is just great.

Pedal saw

Is anyone else bothered by the jerky motion he's going through while pedaling? More frustratingly, the solution is right on the bike still, use the rear wheel as a flywheel.

The problem is he’s doing the actual cutting when his left leg is in the downstroke. I assume that most right handed people are also left right dominant, so homeboy here is doing all the real work here with his goofy foot.

Still, I think a flywheel would greatly smooth out the jerkyness of the saw and make it nicer on the user to operate.

Wait... Is the saw just attached to the right pedal? How is that helpful? It could have been attached to the rear wheel.... And then you have gears... And torque... And things...

Signature Machine

I once worked at a place that had several of these signing a prominent televangelist's signature on solicitation letters. I was told the reason they did this is it is considered a 'real' signature as opposed to a photocopy.

Real as in faked to look real.

Saved you a Google: It's the signature of Pierre Jaquet-Droz, an eighteenth century maker of famous automata, including the Writer and The Draftsman, which worked on similar principles to this. This device was made as an homage to him, as opposed to an Autopen that replicates a living person's signature for official documents.

https://en.wikipedia.org/wiki/Pierre_Jaquet-Droz

There have been laws passed that treat autopenned signatures the same as a "real" signature! https://en.wikipedia.org/wiki/Autopen

There is even a law specifically saying that the president of the united states can "sign" things with an autopen, and it counts the same as if they actually signed it!

Try one of these subthreads