Joel in his minecart

This Little Minecraft Mine Cart Of Mine

[Joel] of Joel Creates loves trains and Minecraft. So what better way to combine them than to make a real-life electric mine cart and ride it around?

At first glance, it seems pretty straightforward. Four wheels, each with a flange, mounted to a box with a motor. In practice, it was a little more complex than that. Just finding a spot of track to even ride on is tricky. Most “abandoned” tracks that you might see around your city often aren’t all that abandoned. Luckily for [Joel], he remembered an amusement park in the area that he went to as a kid, which he remembered having a decent amount of track. Additionally, the rails were smaller and closer to the scale of a real Minecraft track where one block is 1 meter. After calling up the owner and receiving permission, Joel began to build his cart.

First attempts to procure actual train wheels were foiled by cost and lead times, and simply CNCing a set of wheels was too expensive from a time and materials point of view. [Joel]’s first thought was about making an assembly out of two wheels to grip the rail, much like a roller coaster. However, there were dozens of switch points on the track at the park and several road crossings, both things that wouldn’t work with that sort of setup. Stumbling upon a bit of hacker inspiration, [Joel] turned to brake drums, which happen to be reasonably close to the correct size. They also have the superb quality of being relatively cheap and available. Almost all the parts were CNCed out of aluminum, plywood, or foam.

Given that the theme of the build was doing things to scale, [Joel] was mindful of the top speed of a minecart in the game, which is 8 meters per second or roughly 25 miles per hour, so he set that as his goal to hit. A beefy motor from an online warehouse and a lithium-ion pack allowed him to hit that easily; it was just a matter of doing so safely.

If you need even more Minecraft vehicles in your life, perhaps an RC boat might do the trick? Video after the break.

Continue reading “This Little Minecraft Mine Cart Of Mine”

TrackRobot Sports Welded Steel, Not Plastic

Don’t let the knee-high size of [Hrastovc]’s creation fool you. TrackRobot weighs in at a monstrous 60 kg (130 lbs) of steel, motors, and battery. It sports two 48V motors in a body and frame made from pieces of finger-jointed sheet steel, and can reach speeds of up to four meters per second with a runtime of up to an hour. The project’s link has more pictures as well as DXF files of the pieces used for the body.

Currently TrackRobot is remote-controlled, but one goal is to turn it into a semi-autonomous snow plow. You can see TrackRobot going through its first steps as well as testing out a plow prototype in the videos embedded below.

Continue reading “TrackRobot Sports Welded Steel, Not Plastic”

How To Make A Human Crossbow

Say you have a team of French engineers, a lake in the summer, a wizened old machinist, and some gigantic bungee cords. What would you build? The answer is clear, a human-launching crossbow. (Video, and making-of embedded below.)

the-human-crossbow-how-we-made-it-kim41mdcizymp4-shot0001You can start out watching the promo video because it looks like a lot of fun, but don’t leave without watching the engineering video. What looks like a redneck contraption turns out to be painstakingly built, and probably not entirely a death trap. The [Rad Cow] team even went so far as to purchase metal cart wheels.

Everyone else on the Intertubes would tell you not to do this at home. We say go for it. That is, draw up reasonable plans, work with an obviously competent machinist, and make something silly. It’s not going to be more dangerous than the stuff that [Furze] pulls off.

Continue reading “How To Make A Human Crossbow”

Hacklet 81 – Tracked Projects

Sometimes wheels just don’t cut it. When the going gets tough, the tough make tracks. Continuous track drive systems – aka tank treads, or tracks, have been around for centuries. The first known use in relatively modern history is a system designed in 1770’s by [Richard Lovell Edgeworth]. Since then there has been a slew of engineers, hackers, and makers who have contributed to this versatile drive system. Today, tread systems find their way into plenty of robotics and transportation projects. This week’s Hacklet is all about some of the best track drive projects on Hackaday.io!

track1We start with [jupdyke] and Modular Continuous Track System. [Jupdyke] has made a project out of making the tracks themselves. These tracks are strong – shore 70A urethane rubber is no joke! Quite a bit of research and experimentation has gone into this project. [Jupdyke] started with 3D printed parts, before moving on to molded 2 part rubber. The rubber is cast in custom machined aluminum molds. The molds are even heated to ensure a quality casting. Rubber alone doesn’t make a track though. The backbone of these tracks are machined steel pins. The pins go through the treads and connect through roller chain components. We’re betting a set of these tracks could easily carry a person!

robot-tankNext up is [williamg42] with Expandable Ruggedized Robotic Platform. [Williamg42] describes this vehicle as “able to operate in harsh environments”. We would shorten that to “It’s a beast”. Some incredible machine work has gone into this robot, especially on the suspension and idler wheels. Everything is made of metal – the frame is 8020 aluminum extrusion covered in plates. The suspension is aluminum and steel. Motors are mini-CIM motors. This robot isn’t lacking on brains, as a BeagleBone black controls it through a custom cape board. Next time we go out on a desert trek, we want this ‘bot at our side!

ttbn-alphaFrom the mind of [TinHead] comes TTBN Alpha, a TelePresence robot. TTBN alpha is based on a Raspberry Pi. Rather than start with Raspbian, [TinHead] built his own lightweight Linux distribution with buildroot. Control is through a web interface. The operator’s view of the world is through the electronic eye of a Logitech C110 webcam. [TinHead] printed his own tracks, using straightened paperclips as pins. Two servos modified for continuous rotation serve as the main drive motors.

 

surocam

Finally we have [Hendra Kusumah] with Surveillance Robot Camera (SUROCAM). SUROCAM was [Hendra’s] project for both the 2014 and 2015 Hackaday Prize. The chassis is based upon the common RP5 robot kit. This robot’s DC motors are driven by the classic L298n driver chip. Unlike TTBN Alpha above, SUROCAM uses a full Raspbian install, so this Pi is ready for anything. The code is written in Python, and pagekite and ngrok to help make connections to the outside world.

If you want to see more tank treaded rovers, check out our new tracked projects list. Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet; As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Hackaday Prize Entry: Molded Tracks For Vehicles

There are a lot of robotics platforms out there, and whether for educational use or for robot fightin’ time, two things remain constant: tracks are often the best solution, and there aren’t very many modular track systems that can be used with a variety of designs. There are even fewer that can be built at home. [jupdyke]’s project fixes that. It’s a modular and easy to replicate system for tracked vehicles.

The design for this system of track uses roller chain, chosen because the components of roller chain are mass-produced in incredible quantities, sprockets are available in every imaginable size, and all the parts are available in different materials.

Rolling two chains around a few sprockets isn’t a problem; the hard part of this build is figuring out how to make the actual treads, and then making a lot of them. [jupdyke] is making them by 3D printing a few mold masters and doing a few test prints with silicone and polyurethane rubber. For a one-off project, it’s a lot of work, but if you’re making thousands of tracks, molds are the way to do it.

Continue reading “Hackaday Prize Entry: Molded Tracks For Vehicles”