NXT Nerf Barricade Turret

To be precise, "Remote Controlled Fully-Automatic Lego Mindstorms NXT Nerf Barricade Turret" This thing really needs a nickname... (Comment if you have good ideas)

RCFALMNNBT?

 

Description after the jump:

Robotics Competiton Hint

In case you were wondering how to make your robot grab cubes and lift them to score with only one motor, here's a simple mechanism that is able to to both. It isn't robust enough to wok well in the competition yet, but with a bit of modification it could work quite nicely.

Hint:

DroidFreak Lego Robotics Competition 2012 - rules

Welcome to the first DroidFreak Lego Robotics Competition. This competition will be conducted over the internet, so anyone can enter by building a Lego robot and posting it online. Spread the word to anyone who might be interested so they can enter too.

See my playing field post for some of the basics.

There will be three categories in the competition:

NXT only:
This category allows only the electronics from one Lego Mindstorms NXT set to be used, the sole exception being an IR receiver sensor if you wish to control your robot via IR. This places all contestants on a reasonably level playing field, though it will be difficult to make a 3-motor robot perform all the functions (That's why I allow going around the obstacle).

NXT + PF:
This category allows the electronics from one NXT set, IR receiver and/or IR link sensors, and Power Functions electronics consisting of 1 battery box, one receiver, and the number of motors Lego recommends to be used with a battery box (2 XL, 1 XL + 2M, 4M). By giving robots a few extra motors this category makes it much more feasible to perform all the game's functions.

All Lego:
This category allows any and all Lego electronics. Have fun building a complicated machine that can use any number of NXT, RCX and PF motors, not to mention all the other Lego electronics. If you have enough Lego electronics you could build a robot for this category that performs extremely well in the game.

Robotics Competition: playing field

I have decided to hold an online robotics competition over the next few months. I don't have all the rules worked out yet, but I do have a playing field for you to play around with. It's a fairly simple playing field. It has 3 major field element arrayed in a line about a foot (30 cm) apart. Some of the playing field elements are not Lego, but Lego substitutes are allowed.

Playing field overview

In the center of the field is an obstacle. This obstacle should be a large book or a Lego plateau of similar shape. It should be about 1.25 inches (3 cm) tall and at least 8 inches (20 cm) long in the direction of the playing field's "line". The width from side to side doesn't matter much because there will be penalties for going around the obstacle. As long as it is wide enough for your robot to easily cross over there should be no problem.

Obstacle examples

Plateaus are difficult to construct out of Lego, but here's an inside view of how I made mine. The smaller baseplate is supported by several small Lego towers and held down at the corners.

Lego obstacle inside view

On one side of the obstacle is a triangular stack 15 of Lego cubes. These cubes must be made of Lego pieces, and they must have the exact dimensions 4 studs long by 4 studs wide by 3 bricks tall (approximately 4 studs cubed). The cubes are the scoring elements, so the object of the game is to put them into the goal.

A cube

A stack of 15 cubes

The goal is composed of an empty Kleenex box with the plastic removed or a Lego box of similar dimensions. If necessary, you could make a simulated Kleenex box out of cardboard. Kleenex boxes are approximately 4.5 inches (11.5 cm) wide by 8.75 inches (22 cm) long 3.5 inches (9 cm) tall with a hole 2 inches (5 cm) wide by 7 inches (18 cm) long in the center of the top. My Lego version is 30 studs by 16 studs by 9.33 bricks with a 6 stud by 22 stud hole. Note that my Lego version has no bottom. It shouldn't get flipped over during play so no bottom is necessary.

Goals

Now that you know what the playing field looks like, feel free to make one of your own and start testing prototypes. The full rules for the competition should be out sometime in January. I'm leaving for a week starting at 6 am on New Years Day (ughhhhh), so I won't be working on this for a while.

Sphere Eater

Since I make so many projects that scatter Zamor spheres across the floor, I decided to make a project that picks them up off the floor. I made a simple NXT chassis, then I built a holding tank on top of the NXT brick and an attachment to pick up the spheres. Since it seemed to eat the spheres, I decided to name it the Sphere Eater and I gave it a "Nom" sound effect that it plays whenever it detects a sphere being eaten. Since I already had the sound effect from "Nom Nom Nom Nom Nom Nom Nom", I decided to add some Nyan Cat music too. Fun.

Sphere Eater

To see some pictures and the program...

ToothBot Revisited

As I mentioned in the ToothBot post, the program was pretty bad. For that reason, I decided to rebuild ToothBot and improve the program. The hardware is the same, so I won't explain that again. Here's a demonstration of the new program in action:

ToothBot Revisited

Flash Flood: Sniping lego tank

This is a new Lego tank I made just a little while ago (thus no "Backlog"). It's a bit like Maelstrom in that it's a big tank armed with a Hurricane Launcher, but it's also quite different. It has independent suspension and it features the new Hurricane Launcher mark VI that uses a staggered arrangement like the Hailstorm Launcher to concentrate it's damage into a smaller area. The YouTube video also includes a few clips of my next tank (the one I'm working on now), which isn't very practical but is really cool. It's a nice proof of concept.

Flash Flood

Backlog: Tempest (a "lost" project)

This is one of my "lost" projects, because I made it a while ago but never posted it anywhere online. But I'm getting ahead of myself. Let's start from the beginning:

When I discovered Brian Davis's projects, not only did I find his Zamor launchers, but also his Zamor launching tank. Ogre, his tank, is armed with a Hurricane launcher and has sprung plastic treads. Needless to say, that thing is awesome.

Ogre

After I invented the Tornado Launcher, I finally had a good one-motor weapon to put on my own Lego tank. Because this was during the Robotics season where I was building BogieBot, I wasn't content to give my tank a simple tread base. I wanted to give it awesome suspension. Naturally, my first design used rocker bogie suspension. That turned out terribly, because my tread base was too small and my center of gravity too high. That is, it tipped over really easily. Here's a picture of my original design without its treads:

Original design:

After that design failed, I had a stroke of inspiration. Suspension should allow the treads to bend around the terrain without breaking the frame, so why not just make a bendable frame? You may know this suspension style from Maelstrom, but this came first, and this was where I invented it. Tempest turned out awesome, and although I didn't show the Tornado Launcher firing in the movie Tempest had it and could use it.

Tempest movie:

It's kind of incredible (as in unbelievable) that I left this thing unposted, because it was awesome, but I think I know why. Shortly after I built this, my robotics team realized that BogieBot needed to be revamped, and I spent nearly all my time for a few weeks on rebuilding or reprogramming it. During that time I posted 4 YouTube videos of BogieBot. No wonder Tempest got lost in the rush!

Backlog: Turtle Bot

This was originally posted on NXTlog more than 2 years ago:

Turtle Bot

A bot that wears it's NXT brick on the back like a turtle's shell. It has two Zamor sphere launchers and an ultrasonic sensor in the front. This is the first time I have succeeded in making a compact zamor tank, and I think it is pretty awesome The breakthrough was to have the motor powering the launcher backwards so that I don't have a really long gun. Main pic: top front view pic 2: back aerial view pic 3: front aerial view pic 4: back view w/ spheres in tray pic 5: front view w/ spheres

Launchers!

This is the big thing about this bot. My backwards arrangement enabled me to make this bot compact. Main pic: shows backwards motor mechanism (Normally the NXT would be on top of this part. pic 2: close up on the actual motor pic 3: another pic of back motor mechanism pic 4: the forward firing mechanism with the tray removed pic 5: the tray

Driving base

 The base of this vehicle is important because it enables the bot to move. Main pic: bottom view pic 2: another bottom view pic 3: pic of the beam that connects motors in the rear.

Movie!

Movie of the bot executing its primary program, shooting you, and doing wheelies. (pic is repeat)

Backlog: ToothBot

This was originally posted on NXTlog. It was my first project after I bought the NXT 2.0 set:

ToothBot

Since I got mindstorms NXT 2.0 a few days ago, I got bored with the models it included instructions for. Robogator in particular is disappointing (poor walking mechanism, and it can't bite anything. I built my own robot with jaws from the starter model, and it turned out quite nicely. It includes only parts that come out of the box with NXT 2.0

Jaws

Ok, maybe only one jaw. The lower jaw would inhibit it biting things. It bites weakish lego walls, and sometimes my feet. (oops!) I'm glad to say it doesn't really hurt. This is all I really added to the quickstart model to make this project. Big thanks to Lego for giving me the base of this project. Pic 1-front Pic 2-top Pic 3-bottom Pic 4-base Pic 5-back diagonal

Movie

The picture is one of the walls ToothBot attacks. The video shows it attacking a few of those walls. The program I used wasn't very precise, but it worked pretty well for a first project. I may have to reconstruct ToothBot and make a better program. UPDATE: I have reconstructed ToothBot and improved the program, see my new blog post.

NOTE: This video never appeared on NXTlog. I couldn't find a way to convert videos back when I posted this project, so you are the first to see it.

More pictures

Pic 1-overall view with jaw down Pic 2-front view with jaw up Pic 3-only back half (identical to starter model) Pic 4-wiring (including manual correction, which I discovered on my own =))

Backlog: BogieBot (FTC)

Last school year (2010-2011) I participated in the FIRST Tech Challenge competition through my local robotics club. In FTC, teams construct robots to compete in a game at regional and national competitions. Last year's game was FTC "Get Over It!"

Game explanation

We designed an innovative type of rocker bogie suspension for our robot, which we named BogieBot. The Lego prototype that I personally built was able to climb over all the terrain, even climbing up the cliffs!

 Prototype video

Our first scoring design was very ambitious. We tried to make an large arm head with conveyors on a huge arm that would grab and score batons.

Arm head teaser

Unfortunately, the arm head unbalanced the robot and the arm was so heavy it burned out motors. On top of that, it was nearly impossible for it to dispense batons (too much precision required). After our first competition, we tore out the entire arm assembly and designed a new scoring mechanism. It included a fast baton dispenser made mostly out of Lego parts.

Dispenser teaser

It included many other parts too, but I won't spoil it for you. Presenting... The completed BogieBot.  

Full robot

Thanks to technical difficulties, we didn't do well enough to qualify for the national competition, but we earned valuable experience and we made one of the best robots out there.