Nissan Leaf Batteries Upgrade Old Truck Conversion

March 5, 2016 by Gerrit Coetzee 22 Comments

[Jay]’s Chevy S-10 electric conversion needed new batteries. The conversion was originally done with a bank of lead acids underneath the truck bed. With lithium battery factories so large they can boost an entire state’s economy being built, [Jay] safely assumed that it just wasn’t worth it to spend the money to replace it with a new set of the same.

Just like unwrapping a present, from around a tree. — One brand new battery pack!

You should remember the beginnings of this story from our coverage nearly a year ago. Being the kind of clever you’d expect from someone who did their own EV conversion, he purchased a totaled (yet nearly new) Nissan Leaf with its batteries intact. It took a little extra work, but after parting out the car and salvaging the battery packs for himself he came out ahead of both a new set of replacement lead acids and an equivalent set of lithium cells.

He has just completed the first test drives with the conversion, having built 48 Leaf cells into blocks resembling the volumes the old batteries occupied. He had to add some additional battery management, but right-off-the-bat, the conversion netted him more amps and 650lbs (295kg) less weight for the same power. Nice!

We linked to all the posts tagged leaf on [Jay]’s blog. There’s a lot going on, and the articles aren’t all linked to each other. It’s a really cool build and there are definitely tricks to learn throughout the whole process. If you have an hour to kill, [Jay] recorded the entire 26-hour process in a 66-minute video that is embedded below. It’s fun to watch him build up and mount the different modules and gives you a deep appreciation for his devotion to the project.

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Arduino Makerbeam Live Plotter Controlled By HTML5 Canvas And Java Website

March 4, 2016 by Gerrit Coetzee 8 Comments

We’ve never seen someone build a plotter out of buzzwords, but [roxen] did a really good job of it. The idea is simple, place the plotter over a sheet of paper, open a website, draw, and watch the plotter go. Check out the video below the break.

The user draws in an HTML5 Canvas object which is read by a Java Web Server. From there it gets converted to serial commands for an Arduino which controls the steppers with two EasyDrivers.

The build itself is really nice. It perfectly meets the mechanical requirements of a pen plotter without a lot of fluff. The overall frame is T-shaped, for the x- and y-axis. The movements are produced by two steppers and acetal rack and pinion sets. The pen is lifted up and down by a hobby servo.

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Get Really Basic With Steppers And Eight Buttons

March 3, 2016 by Gerrit Coetzee 21 Comments

[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.

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Materials To Know: Acetal And Delrin

March 3, 2016 by Gerrit Coetzee 65 Comments

Delrin, Acetal, and its many trade names is a material properly known as Polyoxymethylene or POM. It is one of the strongest plastics and is a good go-to material when you want the best properties of plastic, and don’t need the full strength of a metal part. It was originally formulated to compete with Zinc and Aluminum castings after all.

I won’t go too deep into the numbers behind POM. If you need the Young’s Modulus, you probably don’t need this guide. This is intended to be more of a guide to its general properties. When you’re looking for something to fit an application it is usually easier to shift through the surface properties to select a few candidates, and then break the calculator out later to make sure it will work if you’re uncertain about the factor of safety.

The most popular property of POM is its ease of machining. While doing this research every single site I came across referred to it as the most machinable plastic. That’s about as objective as subjective praise can get. It doesn’t tend to grab tools like, for example, HDPE. It also chips nicely unlike UHMW and Nylon. Some plastics, like UHMW, have the unfortunate tendency to render the dials on a mill or lathe meaningless as the plastic deflects away from the tool. POM does not do this as much. Of course these other plastics have their strengths as well, but if any plastic will do, and you’re machining, POM is a very good choice.

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Incredible Marble Music Machine

March 3, 2016 by Gerrit Coetzee 44 Comments

We tried to figure out how to describe the band [Wintergatan]. It took a lot of googling, and we decided to let their really incredible music machine do it for them. The best part? Unlike some projects like this that come our way, [Wintergatan] documented the whole build process in an eight part video series.

The core of the machine is a large drum with two tracks of alternating grey and black Lego Technic beams and pins. The musician sequences out the music using these. The pins activate levers which in turn drop ball bearings on the various sound producing devices in the machine. The melody is produced by a vibraphone. At first we thought the drum kit was electronic, but it turns out the wires going to it were to amplify the sound they made when hit. At the end of their travel the bearings are brought up to the hopper again by a bucket conveyor.

The final part count for the machine sits at 3,000 not including the 2,000 ball bearings rolling around inside of it. If you’ve ever tried to make a marble machine, then you’ll be just as impressed as we were that the machine only appeared to lose a few marbles in the course of a three minute song. Aside from the smoothness of the machine, which is impressive, we also enjoyed the pure, well, hackiness of it. We can spy regular wood screws, rubber bands, plywood, bits of wire, and all sorts of on-the-spot solutions. Just to add bonus cool, the whole project appears to have been built with just a bandsaw, a drill press, and a few hand power tools.

The machine is great, but we also really appreciate the hacker spirit behind it. When a commenter on a YouTube video told him he was a genius, he replied, “Thank you for that! But I do think, though, that it is mostly about being able to put in the time! I mean the talent of being stubborn and able to see things through are more important than the abilities you have to start with. If you work hard on anything, you will learn what you need and success! Its my idea anyway! So happy people like the machine!”. Which we think is just as cool as the machine itself. Video of the machine in action and part one of the build series after the break!

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When Life Gives You An F-15 Throttle Grip Make A Cool Joystick

March 2, 2016 by Gerrit Coetzee 21 Comments

We’re not certain where [NoPleaseDont] got an F-15 Throttle Grip, but it would certainly be a waste not to make something cool out of one. The F-15 is a twin engine air superiority fighter, and in it’s niche, it is one of the most successful ever made. We imagine this makes it a popular choice in air simulators.

Equipped with his successful scrounge [NoPleaseDont] decided to build a full HOTAS, Hands On Throttle and Stick, joystick. He started by taking apart the throttle grip. As each layer was pulled a part, we were pleased to see the reassuring infestation of quality control stamps you’d expect to find on the input of a 26million dollar machine. The pinouts were presumably taken and the handle was reassembled. After that, a lot of custom sheet metal parts, 3D prints, and clever bracketry came together to form the frame of the joystick.

Finally came the electronics. Many of the photos were too blurry to decode, but at minimum a Teensy and custom LED control board is involved. The frame got a few additional buttons and control panels added.

The resulting joystick has a great history, and more buttons than we can guess the purpose of.