[This Old Tony] teaches us how to make springs on a lathein this video done in the style of How It’s Made. Mixed in with snark, in his usual style, is a lot of useful information.
The Machinery’s Handbook certainly has all the information one would need to design the basic spring shapes, but it’s not always necessary. [Tony] points out that cheating is entirely acceptable. For example, if you need a spring that’s close to the dimensions of a standard spring, simply copy over the values from the standard spring. He explains all the terminology needed to decrypt the pages in your engineering tome of choice.
He shows the basics of winding a spring on a mandrel (or that round metal thing, if you want to use the industry term). First wind the inactive coils, then set your lathe to the desired spring pitch. Engage it as if threading, then disengage and wind the final inactive coils. A quick trip to the sander squares the ends of a standard coil spring. However, the tools can also be used to make torsion springs, or even exotic combination springs.
For a good… educational laugh, watch the whole video after the break.
This robot may have the fastest hand we’ve ever seen. It’s only a hand at the moment, but it’s certainly good with it.
The hand comes from a research project out of the University of Washington. The researchers didn’t just want to program the robot to do tricks, they wanted it to learn. Some tasks are just by nature too complex and tedious to program all the details for. Look at all those tendon activators. You want to program that?
The current focus of the robot is twirling a stick. While they’re probably a ways away from a robot cheerleading squad or robot drum major, the task itself is extremely difficult. This can be proven by just how many YouTube videos there are on the art of pencil twirling.
While the video didn’t show the robot dramatically twirling the stick at high speed, it did show the robot rotating it a little bit without dropping it. And this is a behavior that it has learned. For anyone who has ever had a run-in with robotics, or the art of convincing a robot not to discard all the data it collects in order to not run directly into a wall, this is a pretty big achievement. Video after the break.
A class in Brazil was given the assignment to make a board game. [Marcelo], presumably, heard his son lamenting how lame it was going to be if the board was just cardboard with some drawings on, and came to the rescue.
Working with the class, they came up with the rules of the game. We’re not certain what those are, but it involves a regular game board, a flashing light circle with numbers, and a fusion between Operation and one of those disease transmitters commonly found at the doctor’s office. You can try to puzzle them out from the video after the break.
The brains of the board is an Arduino with an external EEPROM for all the sound effects and other data needed for this construction. Everything is laid out on a beautifully done home etched PCB. It’s too bad the other side of the board isn’t visible.
We’re sure the kids learned a lot working with [Marcelo]. It would have been nice if a traveling wizard came to some of our earlier classes in school and showed us just how much cool stuff you can do if you know electronics.
[Kevin Darrah] put together a good video showing how to control a stepper motor with, not a motor driver, but our fingers. Taking the really low-level approach to do this sort of thing gave us a much better understanding about the features of our stepper driver chips. Such as, for example, why a half step needed twice the current to operate.
[Kevin] starts with the standard explanation of coils, transistors, and magnets that every stepper tutorial does. When he hooks up simple breadboard with passives and buttons, and then begins to activate the switches in sequence is when we had our, “oh,” moment. At first even he has trouble remembering the correct sequence, but the stepper control became intuitive when laid out with tactile switches.
We set-up our own experiment to see if we remembered our lessons on the subject. It was a fun way to review what we already knew, and we learned some more along the way. Video after the break.
If you want to sell a toy for the toddler crowd, it ought to be pretty close to indestructible. A lot of toys out there are just plain nonsense game-wise and therefore waste their beefy potential. [2dom]’s wife was close to throwing out such a toy—a Little Tikes Goofy Ball. The thing literally does nothing but let you push its big buttons in. After some time passes, it pops them back out again and giggles. Game over. [2dom] rescued it from the trash and turned it into a toy that plays math games.
[2dom] removed the existing board and replaced it with an Arduino Pro Mini and a Darlington array that drives the motor that pops the buttons back out, the speaker, and a Nokia 5110 screen. Upon startup, the user chooses between addition, subtraction, and multiplication questions using the appropriate button. Questions appear in the middle of the screen and multiple choice answers in the corners.
Choose the right answer and the ball cheers and shows one of a few faces. Choose the wrong answer and it makes a buzzing sound and shows an X. There is an adaptive level system for the questions that [2dom] doesn’t show in the demonstration video after the break. For every five correct answers, you level up. His 3- and 5-year-olds love it. For more advanced teachable moments, there’s this toy-turned-enigma-machine.
Sometimes tearing down a cheap appliance is more interesting that tearing down an expensive one. A lot of the best engineering happens when cost is an issue. You may not solve the problem well, but you can solve it well enough for a discount shelf.
[openschemes] purchased a 1.8kW induction hot plate at a low price off Amazon. The reasons for the discount soon became apparent. The worst of which was a fully intolerable amount of high frequency switching noise. Wanting to know how it worked, he took it apart.
After he had it apart on his desk, he deciphered the circuit, and wrote about it clearly. As usual with extremely cheap electronics, some clever hacks were employed. The single micro-controller was used for monitoring, and generated a PWM signal that was instantly converted to DC through some filters. All the switching was done the old fashioned way, which explained why the hotplate seemed so brainless to [openschemes] when he first turned it on.
Lastly, he did some work on manually controlling the cooktop for whatever reason. The good news? He managed to figure out how to control it. Unfortunately he also destroyed his unit in the process, via a misapplication of 1200 volts. A fitting end, and we learned a lot!
“To the Tortuga!” my husband and I heard the announcement from the backyard. Our two boys, Ben (7) and Miles (3), had become pleasantly obsessed with the coolest brothers in nature – the Kratt Brothers. From the moment that these two energetic animal-loving brothers were discovered by our kids, they’ve been huge fans. Our house has been transported to the Sonora Desert where we saved a Gila Monster, then to the Australian Outback to learn about the Thorny Devil. We even went to swing with the Spider Monkeys in South America and then back to the good ‘ole U.S. of A to harness the speed of the Roadrunner – since we are, after all, a family of runners!
Our boys have been the Grand Brothers for months and there are no signs of it letting up. At the end of summer, I decided to reward the kids with a Creaturepod, a plastic toy meant to look like the fictional walkie talkie of the same name used on PBS Kids’ Wild Kratts program. They loved it, but soon found that it didn’t do anything on its own. They both have wild imaginations and like to bring to life most of their play, but the toy just wasn’t doing it for them. Being that Chris and Martin Kratt are brothers in real life, and Ben and Miles Grand are brothers in real life, Ben thought it would only be right to have “real life” Creaturepods. Real walkie talkies that he could use to communicate with his friends and have Wild Kratts adventures. This natural interest provided an opportunity to make learning, designing, and building a source of fun for the boys. It is an amazing way to teach that you can change the world around you by having an idea, making a plan, and gathering everyone with the skills needed to complete the project.