Obstacle Avoiding LEGO Rover Uses CDs For Wheels

September 1, 2013 by 3 Comments

lego-rover

This rover built by [Sath02] is a great example that you don’t have to be a mechanical engineering wizard to get into robotics. He used LEGO pieces to help ease the difficulty of getting a rover up and running.

In this case the use of LEGO is strictly structural. The electronics are not the NXT parts you would expect to see when working with these popular toy blocks. Instead he’s put the Arduino Palm Plus into service. It’s an Arduino board that has rows of holes at either end to make it LEGO compatible. It also carries an LM293D motor controller and [Sath02] added an XBee module for wireless control.

At the top of the assembly is an IR distance sensor which is used for obstacle avoidance. You may not be interested in building and exact replica, but the techniques he uses for attaching the distance sensor, CD wheels,  and fabricating the rest of the rover are good examples if you take on a LEGO build in the future.

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Is A LEGO 3D Printer By Definition Self-replicating?

July 18, 2013 by 35 Comments

lego-3d-printer

LEGO parts are plastic. 3D printers make parts out of plastic. So the transitive property tells us that a LEGO 3D printer should be able to recreate itself. This one’s not quite there yet, mostly because it doesn’t use plastic filament as a printing medium. Look close and you’ll probably recognize that extruder as the tip of a hot glue gun. If all else fails you can use the machine as a precision hot glue applicator.

The instructions to make your own version include the design reference and a few ideas for getting the most out of the glue dispenser. For the design phase [Matstermind] used LEGO Digital Designer. It’s basically CAD with the entire library of LEGO parts available as building blocks. from there he assembled the machine which is controlled by an NXT brick. He goes on to link to a few different printing mediums. There’s instructions for using crayons to make colored glue sticks, as well as a method of printing in sugar using the hot glue extruder.

We remember seeing one other LEGO 3D printer. That one didn’t use an extruder either. It placed blocks based on the design to be printed.

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LEGO LP Player

November 26, 2012 by 1 Comment

This LP player is made entirely out of LEGO parts. It plays the songs encoded on each record, but not by using a stylus in a groove. Instead, each LP has a color code on the bottom of it which is interpreted by the optical sensors underneath.

In addition to its functionality [Anika Vuurzoon] made sure that the build looked the part. The horn is a nice touch, but you’ll also appreciate the rotating mini-figures on the front side of the base. To the right there is a hidden door that provides access to the NXT brick which drives the system. New records are produced using a couple of different tools. First off, the song is written using Finale, a mature musical notation program. That is exported and run through a second program which produces the colored disc design which is applied to the records. You can hear the songs for yourself in the clip after the break.

If LP playing toys are right up your alley you’ll want to check out this 3D printed record hack for a Fisher Price toy.

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Motorized Wheelchair Built From LEGO Pieces

September 26, 2012 by 18 Comments

You’re certainly not going to sneak up on anyone if using this LEGO motorized wheelchair. The high-pitched whine of all those tiny motors sounds like an army of robotic mosquitoes out for blood.

Six of the LEGO Mindstorm bricks are used to drive the motors, with a seventh acting as the master. It’s not pictured above, but there is a joystick on the right hand side which allows the rider to navigate. The master brick monitors the four sensors on that joystick. It then uses a pair of motors to actuate switches monitored by the slave bricks. Each slave has one switch for forward, and another for backward and drives two motors. To get around problems with angular velocities dues to turning, all of the wheels are multidirectional.

The plan is to add Bluetooth control in the near future. The master/slave setup should make that relatively easy as it only affects one of the bricks. The idea is to facilitate Android control to the chair like we’ve seen in other Mindstorm builds.

Don’t miss the demo embedded after the break.

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LEGO ROV Without A Tether

August 14, 2012 by 13 Comments

[Brane] built an underwater ROV from LEGO mindstorm parts. Look closely at this image and you should notice something missing. The tether that normally carries power and control lines from an ROV to the surface is missing. This is a wireless solution that lets him control the device using an Xbox controller.

The video after the break shows about five minutes of test drive footage. [Brane] has a big aquarium in which he can test the thing. Since he put it together as his senior engineering project at University it’s likely that this is a testing facility at the school. Here’s the little we know about the hardware: It’s using NXT Mindstorm parts to control the motors, with a sealed chamber for a battery. Connectivity is provided by an XBee module with an NXT adapter board called the NXTBee. A laptop with its own XBee module makes up the other end of communications. Right now [Brane] uses an Xbox controller connected to the laptop, but a standalone device would be easy to build by hacking the XBee and controller together directly.

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NXT Android Telepresence Robot

August 2, 2012 by 3 Comments

Here is a telepresence robot that uses an Android device and LEGO NXT parts. [Wolfgang] had an extra phone on hand and decided to put it to good use. The Mindstorm parts make it really easy to produce a small robot, and adding the phone really ups the computing and connectivity options available to him.

The Android device is able to control the NXT bot via Bluetooth. [Wolfgang] didn’t go into detail on that part, but you can get some pointers on the topic from this other Android controlled Mindstorm project. [Wolfgang] wanted the ability to check in at home when he’s travelling. He uses nanohttpd on the Android device to serve up a simple web interface. It uses HTML5 to push a snapshot from the phone’s camera as user feedback, and provides a set of directional arrows which let him drive the bot around.

Obviously this thing is going to run out of juice if he’s away for too long. To combat that problem he included a battery which powers both the NXT parts and the phone. Now he just needs to build an inductive charging station and he’ll really be set.

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LEGO Mill Produces Sculpted Models With Fantastic Resolution

August 20, 2011 by 19 Comments

[Arthur Sacek] has really got something with the 3D Mill he built entirely from LEGO pieces. As you can see, it uses NXT parts to control the cutter head along three axes. The drill bit that acts as the mill’s cutting head is not a LEGO part, but that’s [Arthur’s] only transgression.

The demo sculpture seen above was cut into a block of floral foam. The model was processed by Autodesk Softimage before being fed into the mill, where it took about two and half hours to complete the job. The foam comes out still in block form looking like a piece of outdoor carpeting. That’s because there’s no debris removal during the milling process. But hit it with the shopvac and you’ll reveal a physical model with surprising detail. We don’t think it comes close to the light-cured resin printing we’ve seen, but it would be a great asset if you’re doing some mold making.

Don’t miss [Arthur’s] video of the milling process after the break.

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