how to make a Della-WAHR


In this tutorial I will show you how to make a Wall-Avoiding robot with the BS2 board. Other things you will need are:

1) 2 modified Hitec HS-311 servos (

2) a PING)) rangefinder (Radioshack or

3) 1" radius PVC pipe (get about 2 ft to be safe) and T joint

4) a good supply of cardboard

5) twist ties (about 6)

6) rubber bands and lots of tape

7) a small caster (home depot)

8) Velcro

9) obviously a BS2 Board of Education (found at or can be found on ebay for half the price)

The tools you will need are:

1) hacksaw

2) scissors

3) different sized screw drivers

4) box cutter (knife)

Our first step is to cut the PVC to length. You will need three 2 1/2" long sections of pipe. Now, you will need to cut groves into them for servos.

On 2 of the sections, cut groves like this with your hacksaw. The servo should go in about a cm les than all the way and must fit snuggly.

Real photo:


Now the next thing to do is cut the slot for the other section. This one will be for our vertical 180 degree rotation servo. It should go at least 3/4 of the way down the pipe. And this one should fit snugly too.

Real photo:


Now that we have cut the pipe sections, arrange them like this with the T joint.

Real photo:

Now we move on to step #2. Here we will make the platform for the BS2 board to rest on. First cut out a cardboard piece like this and twist tie it onto your frame.

Step three is where we make the wheels and attach them to our HS-311 modified servos (2). We will make our wheels (2) out of cardboard, with a 6" diameter (a large Ovaltine cap works well). Poke a hole in the middle for the servo horn screw.

Real photo:

You may want to add some reinforcements to the wheels (bent paperclips or wooden sticks).

Now take the screw off of the servo horn and put it through the hole (you may want to add a washer) and into your wheel. You may also want to tape it on too. Take your servo with wheel and put it into its slots. If it is loose tape the servo in too.

Step four is adding our PING)) servo combo (the ping is connected to the mounting bracket and the bracket is connected to our servo. put the 180 degree servo into its slot and if necessary and tape.

I secured mine with Velcro and rubber bands since the screws were stripped but you probably wont have to do so.

Now step five is to add the 4xAA pack that came with the BS2 board. Add Velcro to its back and to the bottom of the frame and stick them together.

Step 6 is to position our BS2 board on the robot. it will be on it like so.

( It will hang off the edge but that is ok. You can also add some more cardboad in the back if you like so it doesn't) Twist tie the front onto the cardboard through the front 2 and then attach all of the sensors/servos:

right servo 12

left servo 13

PING servo 14


The final step is to add your small caster. Position it under the PING)) servo and tape it on WELL (you may also add rubber bands) if it is too short then add some small scraps of wood on top of the caster then tape it on.

CONGRATULATIONS!!!!! just plug in the battery pack to your board, upload the attached code and you have a finished the wall avoiding robot for the BS2 board.

Thanks to my good friend Nick for helping me make this

Code modified from code downloaded from

Thanks to everyone at Society of Robots for answering all of my questions on mechanics and electronics.

I never would have been able to do this without you guys.

My robots shake test:

File Size: 12 kb
File Type: bs2
Download File