Monthly Archives: September 2009

September 12, 2009

NXT Dragster 2.0

By ktgorgi

NXT Dragster 2.0

Note: Here is my new improved Dragster. The updated version from 1.0 and 1.5. Hope you like it.

Welcome race fan, get ready to build a NXT Dragster, Program it and don’t forget to make the drag strip. This awesome dragster pulls a wheelie while racing down the track.

Key Features:

1. Pops a Wheelie
2. An adjustable wheelie bar lets you control how high the wheelie at the start will be and how long the dragster will hold the wheelie. Gears are used to speed up the NXT motors to achieve more top speed during the run.
3. It times it self. (Displays Time after each run.)
4. Has 4 sensors on board.
a. Ultrasonic for avoiding crashes,
b. Color for detecting the finish line and start line.
c. Accel to see how big the wheelie is. How much if a slate.
d. Compass to see where it is heading.
5. Requires 2 NXT so you can see the data from the sensors wireless.

What you need:
Computer with NXT-G software plus Lego Digital Designer.
2 NXT’s
Hitechnic Compass Sensor
HiTechnic Accel Sensor
HiTechnic Color Sensor.

Scroll down to learn how to build Dragster 2.0, program and build the drag strip.

Building NXT Dragster 2.0

Step 1: Using the LDD file build the dragster. Note: All the parts that are not connected to the main body. Those are needed to build the rest of NXT Dragster 2.0. (All the parts in the ldd file is all you need.) The only problem is that LDD can not put beams a a very certain angles. Note: Their is an extra NXT in the LDD file. That is used as your hand held NXT. The hand held NXT is used for giving you data from the sensors right in the middle of the drag run using bluetooth. O.k so their are 3 sections that I could not attach to the main body in lego digital designer.

a) The Back Wing. (e.g of Back Wing on NXT Dragster 2.0)

b) The color sensor. A beam needs to be attached or the color sensor won’t be in the right position

c) Connecting the NXT to the body. (The NXT is already connected but their is one more connection to be made, or the NXT will not be stable.) Connection means by Technic parts Scroll down to build the rest of NXT Dragster 2.0

Click Here to Download the LDD File to Build NXT Dragster 2.0

Add the Back Wing:

Step 1: Connect the Cross Axle 8 (2) to the motors. (Do this step 2 times.)

Step 2: Add the Bush for Cross Axle to the Cross axle 8. (See picture on the top right for details) (Do this step 2 times)

Step 3: Connect the back wing to the Cross Axle. (Picture of the Back wing on Dragster is top right.) (Back Wing in LDD is also here if you have trouble finding it.)

Stabilize Color Sensor

O.k. for the color sensor to work you have to add a Technic Angular 4X4 beam so it does not move back and forth. As you can see the beam is one hole up then it should be. Use the pictures to help you. O.k. you are done with building Dragster 2.0 but their is 1 more thing we need to cover. Scroll down to continue.

Connect NXT to Dragster 2.0

Step 1: Connect the NXT using the Double Anguler Beam 3X7 45 (degrees) (See Pictures)

Dragster Wheels – What You Need to Know

If you want this dragster to pop a wheelie. You need to choose the right wheels. If you don’t you will have to add extra weight on the Dragster to make the wheelie. The best wheels are in the top picture. These wheels are in the Lego education resource set and I think in lego education base set. You will always get a wheelie. The second best are in the middle picture. These wheels are in the retail version of Lego Mindstorms NXT 1.0 Set. They will sometimes work. You might have to add extra weight to the back of NXT Dragster 2.0. The last, and worst are the wheels in the bottom picture. You will have to add weight to the back.

Building the Drag Strip

What you need: 5 pieces of black construction paper. 1 roll of tape 1 pair of scissors 1 hunk of sticky tack (note sticky tack not in picture)

Step 1: Fold 1 piece of black paper in half.

Step 2: Unfold the piece of paper and cut along the crease using your scissors.

Step 3: Position the piece of paper (just one half), and tape to the floor. This is your starting line

Step 4: Using the rest of the black sheets of paper. (4 sheets) Create your finish line. Use the picture to help you. Once it is in position. Sticky tack it to the floor. You are done making the drag strip. Now it is time to program. Note: Please make sure their is at least 1 NXT Dragster 2.0 in length at those sides of the starting and finishing line. Why? Because you have to put the NXT Dragster 2.0 behind the starting line. Also after the finishing line because it coasts to stop. and it should not run into things. (Please look at the left and right picture for details.)

The Programs

Here are the 2 programs that need to be downloaded on to the NXT.

Here is a run through of them: NXT Dragster 2.0:

1. Move forward and stops on the starting line.

2. Countdown begins.

3. Dragster goes in high gear and pops a wheelie.

4. Dragster finds the finish line.

5. Dragster stops.

6. Dragster shows Drag Run Time.

Hand Held NXT Remote: 1. Press orange button to start getting messages.

2. Displays data of the NXT Dragster Sensors. The Hand Held NXT has to be connected to the dragster using bluetooth. The Book that came with your NXT should show you how. More Bluetooth Notes: The hand held NXT is the Master and the NXT Dragster 2.0 is the slave.

Click Here to Download the NXT Programs for NXT Dragster 2.0

NXT Trainer

Do you hate counting reps for your push ups or Sit up? Do you hate timing your self when doing a plank? If you answer yes to these questions you should try NXT Trainer.

Key Features:

Counts Push – Ups and Sits – Ups
Times you when you do a plank.
Writes reps and time on files on the nxt so you can download them onto your computer and see how many reps you did in total.

How to build NXT Trainer:

All you have to do is use the LDD file to build it.

Click Here to Download the LDD file for NXT Trainer

The Program

The NXT Trainer uses 3 myblocks plus the main program. You can download the programs on the the NXT here.

Notes: You have to edit the programs and make my blocks for the main programs to work.

Click Here to Download the Programs for NXT Trainer:

Here is the sensor port list:

Touch Sensor = Port 1

Sound Sensor = Port 2

Light Sensor = Port 3

Ultrasonic Sensor = Port 4

How to do Sit-Ups With NXT Trainer:

1. Put NXT Trainer on a table so every time you do a sit up, the Ultrasonic sensor detects your head.

2. Turn on the NXT and Select NXT Trainer Program.

3. Select Sit – Ups in the next window. (Number 0)

4. Lie down and get ready to do a sit up.

5. Say go while lying down.

6. The NXT should say start.

7. Start doing your sit – ups.

8. Every time you do a sit – up their should be a tone to tell you that the ultrasonic sensor detected you. (If you stay in sight of the sensor to long. The NXT Trainer will count it more than 1.)

9. When you are finished lie back down, and stay down. The NXT should stay Stop, and yo can look at how many sit ups you have done.

How to do Planks With NXT Trainer:

1. Put NXT Trainer under your stomach.
2. Turn on the NXT and Select NXT Trainer Program.

3. Select Plank in the next window. (Number 1)

4. Get into your plank position

5. Say go while in the plank positions.

6. The NXT should say start, and the timer will start.

7. When you want to stop. Put your stomach on the touch sensor. (Note: Do not put your full weigh on it).

8. The NXT should say stop, and you will get to see the time of your plank.

How to Do Push Ups With NXT Trainer:

1. Put NXT Trainer under your stomach.
2. Turn on the NXT and Select NXT Trainer Program.

3. Select Push Ups in the next window. (Number 3)

4. Get into your push up position position

5. Hover your thump above the light sensor. The NXT should say go.

6. Every time you go down. Your stomach should touch the touch sensor. After being touch, the display will update with how many push ups you have done. (If you stay on the sensor to long. The NXT Trainer will count it more than 1.)

7. When you are done doing push – ups hover your finger over the light sensor. The NXT should say stop.