How to Build a Robot - the BeetleBot V2 ( Revisited )

This is the beetle robot instructables revisited a la MythBusters style!
I originally made a instructables about my beetle robot version 1.

It is now time to show you a new version of this wonderful robot. This new version is much easier to build and fool proof!

The beetle robot (Beetle bot), is a very simple and efficient robot that use no electronics component to avoid obstacle in his path. It use two SPDT switch to avoid obstacles by reversing the opposite motor to pivote and free himself. There is no silicon chip, that is, no integrated circuit, no transistor, no resistor, capacitor, etc.
This mean very cheap to build!

The major modification is the cross antenna. When you have cross antenna, obstacles like a chair leg won't be any danger to the robot. The robot will be able to avoid it. On the original design, the antennas where in a V shape and the chair leg would go right in the middle of the V and the robot would had a hard time to get free.

By having the cross antenna, it also help with the assembly of the robot. The switch are closer together which help in the soldering of the wires.

Here is a little resume turn into a video. Check it out!



This article was created because I got contacted by a Make editor. I then took pictures and redid the beetle for an article that I wrote in the MAKE magazine Volume 12.

After a few month I saw this: Top articles in MAKE 1 - 12.
http://blog.makezine.com/archive/2008/03/top_articles_in_make_1_12.html?CMP=OTC-0D6B48984890

It turns out, that my article was one of the most read of there digital magazine!
Here is the digital version of my article.
http://www.make-digital.com/make/vol12/?pg=150

I took 134 pictures, that is 235Mb of files! I had a really hard time to choose the perfect pictures to make this instructable!

In 2010 I made a internship at www.solarbotics.com and made this solderless kit
http://www.solarbotics.com/products/k_jb/
Look at blue and the green beetle bot in the pictures! They look awesome!
The only thing you need is a screwdriver that we give in the kit!




Thank you!

Jerome Demers
www.JeromeDemers.com

This is what you will need to build this robot.

Items for the robot:
2 x 1,5V motors
2 x SPDT ( single pole double throw ) switches with a metal lever
2 x AA or AAA battery
2 x Terminal connector ( see picture )
1 x AA or AAA battery holder
1 x Plastic or wooden pearl ( Spherical bead )
1 x 1 inch x 3 inch piece of metal or aluminum
1 x Toggle switch for the on/off switchs

Paper clips big and small
2 feets of wires around 22/24 Gauge size
Heat shrink that will fit over the motor shaft and some that will fit over the terminal connector
Electric tape and masking tape

Items for the body shell :
Round plastic lid to make the shell of the robot
Some spray can paint, the colour you want.
Clear varnish
Autobody filler putty or epoxy glue
2 x Small magnets to attach shell to body.

You need some 1,5Volts motor, not 3V or no event 12V!!
Each motors are powered by a single AA battery. You will drain your battery if you use a bigger motor. You can find them in toys or even at your local dollarrama, in little car, fans, etc! ( beware, they might really suck you battery down )

the recommended tools for this project:
1 x safety glasses!!
1 x soldering iron
1 x glue gun
1 x wire strippers
1 x side cutter
1 x scissors, knife, x-acto, etc

I recommend you to take the time to read this entire instructable before starting. In every page I have added a lot of pictures, so don't forget to look.

This is the main component for this robot. The most expensive.

You might get them free or pay from 1$ to 4$ each.

the SPDT switchs need to be really sensitive! These switches are the most expensive part of the robot... around 1$ to 4$ each. The one I use are from Cherry.
http://www.cherrycorp.com/english/switches/sealed/dcjk.htm

If you recycle old electronic, it might be all FREE! Try searching old VCR, PS2, old toys, printer, etc
Back then, I use to recycle everything, I got everything FREE, old VCR are very good for gears and something SPDT switchs!!! Playstation have great motors, the one that makes the laser move.

-- edit july 5 2008 I was surfing the website and found this cool instructable
https://www.instructables.com/id/Recycle-old-PCB-components/
His name is Nick and he is 14 years old!
He told me that is was going to build the beetle robot this weekend because he has all the parts!
He took the time to recycle. :P I did the same thing when I was his age! :)

At the end of his tutorial, I saw a picture of the blue recycling bin of is municipality - Blainville! That is like 10km from where I am living while making my internship!!

The world is small!

end edit --

The SPDT switchs position is the new twist in this design.

You are going to cross the antenna so that nothing can get stuck between a chair leg like the old design.

Glue them together like in the picture. Hot glue will do.

You need grip to get around! Without tires, your car won't go anywhere. Try driving on your rims... does this make you think of police footage, bad guys trying to get away with busted tires :P

Same thing with the beetle robot.

The shaft of the motor is the rim and the heatshrink is the tire. Since the robot rests on the shaft of the motor to move around, you will need some grip.

You will need to shrink the heatshrink onto the motor shaft. I use a heat gun but the tip of your soldering iron will do.

Here we are going to build a motor mount instead of glueing the motors to the battery holder.

It will look more professional.

Take your metal or aluminium plate and cut it to make a rectangle 1 x 3 inch. It does not really need to be exactly 1 x 3 inch.

If you don't have access to aluminium you can glue the motors to the battery holder.

You can also salvage metal from a old computer, VCR, etc.
In a lot of electronic equipement they have metal plates that are used to reduce parasite noise by grounding these plates to the main ground of the equipement. These plates are easy to cut with metal scissor.

This is an easy step but you need to be carefull for the motor polarisation.

If you get this step right, you have good chances it will work the first time!
( I hope so :P )

Look at this picture to understand. I have use electric tape to attach my motors.

Here we simply glue the metal plate to the front of the robot.

These are a few problems that arose:

1 - The motor mount unglued from the battery holder.

You can simply glue the metal plate to the battery holder with epoxy. You will never be able to remove it!

Here is my tip: I tape a piece of masking tape to the battery holder and one to the motor mount. I then use epoxy to glue the two parts together. The glue dries onto the masking tape and not on the plastic of the battery holder. If one day I need to remove any item, I simply rip off the masking tape! Clever hen? In resume, you glue two pieces of masking tape together!

2 - The front of the robot is too heavy and the robot tilts to the front.

To avoid the tilting, you can try to mount the bracket to the front and not to the middle. This might not really help. On the next step you will see another solution. You can always put some weight on the back of the robot.

You will need the big paper clip and the plastic or wooden pearl. These pearls are exactly the one found on neckless.

You don't really need a round pearl. You can have the entire robot rest on the bare paper clip.

The other step is to glue the paper clip to the battery holder.

Here is another precaution. The way I have glued the paper clip is not super super.
It will not hold on very well. Be sure to put a lot of glue!

You can glue the paper clip on top of the battery holder.

You remember the problem with the heavy front? You can make a long caster to prevent the front to tilt. ( see picture )

Here we start soldering!

It is going to be really easy!

Check out the pictures! I have used a paper clip to make the middle connection.

I took some black electric tape to cover the aluminium plate. This was an aesthetic feature when taking pictures and it helps remove flash reflection.

I took paper clip to solder from the motor to the commun pin of the switches.

You are going to solder a wire between the motors.

Here is the principal and most important thing about the beetlerobot.

It is call the "third connection"

In you AA/AAA battery you have 2 wires that provide 3Volts.

In reality, we only use 1,5Volts for both motors.

How can we get half the voltage? Simple, you solder a wire like the picture below.
The new wire will touch the last wire you have solder in the last step and you will connect it to the battery holder. See picture.

Be very carefull when soldering to the battery holder, you can melt the battery holder! I have already done that. This will happen with cheap AA holder.

Here you are going to hook up the power to the robot. On your AA or AAA battery holder you have a red and a black wire. Like you probably know, the red wire is positif ( + ) and the black is negativ( - ).

Solder the wire like on the picture and everything is ready to be tested.

Put some battery in it.
Both motor should turn.
By pressing the left switch the left motor should turn the other way.
By pressing the right switch the right motor should turn the other way.

You are now ready to make the antenna.

This is the cool part of the design. When applying this principal you can remove the antenna and pack it into your backpack!

Take those terminals and remove the plastic. You will be able to solder to the terminal.
Take your pliers to press down on the terminal connector. After that, you will be able to slide it tight on the metal connector of the SPDT switches.

Check out the next step.

Use paper clips to make the antennas. The feelers (sensors) of the bettle robot.

Solder the antennas to the terminal. I have added a heat shrink over my solder to hide it.
Clip the antenna onto the metal bracket of the switchs. If it's too loose, go back to step 14.

Your bettle robot is finished!

The following steps are going to make your robot more easthetic by adding a shell to the robot.


The next step is adding a switch to the robot instead of removing the battery.

Your robot should be able to move around and avoid obstacles.

To stop your robot, you need to remove the battery. This can get annoying and I recommend adding a simple switch.

Look at the pictures and you will understand. I have added heat shrink to make it look nice and hide my beautiful solder joint.

To make the shell, you can use any sort of plastic container. The dark green is a peanut butter cap and the transparent green is from a gel container.

I decided to use the transparent cap to make my shell. I then cut out the cap to make room for the motors and the switches.

Like you have seen on the pictures, the gel cap is not really round. To cover the holes I have used a body car putty. Beware, car putty cure really fast!!

I have file down the cap to make the entire cap rough. This will help the putty to grip. Let it dry and after you can file it again to make everything smooth. Once it's dry, I have used another putty for the finishing touch.

I did the same thing and filed everything.

If you don't have access to putty, you can use epoxy glue, it will work great. Let it dry 24 hours before sanding. Epoxy glue can be very liquid so be careful. Take your time.

After sanding the lid smooth, it is time to paint it. Give it a couple of coats of primer.

After that you can start painting the shell in black or any other colour you like.

Give a couple of paint layers and let it dry. Take you time. I normally do that outside in the sun.

It is now time to add the circles to the robot. I took a coin to make the circles. I have used masking tape to make the circles.
Put them anywhere you want.

Take a other colour you want and start painting.

Spray at a distance of 20 cm and one layer at the time. Give it a couple of layers.

Remove the stickers... I had some bad finish. The glue of the masking tape made some residue.
Check out next step to know how to take them off.

To remove the residue, I took sandpaper and sanded with water. Use some very fine sandpaper and add some water. This will give a glossier finish.

I then used a black pen to make the outline of the circles. You can skip this step.
I just wanted to hide all the imperfection.

Yes I could of call this the ladybug robot!

I wanted to paint blue and yellow, green and yellow, etc

There are so many colours you can use.

Everything is finished..

Not really, you need to hook up the shell to the robot.

To connect the shell to the robot, you can glue it directly to the battery holder, or you can use magnets; glue one inside the lid and another in a mathcing position on the battery holder.

I have switched the yellow tape with black to make it nicer. I have also painted the antenna black for aesthetic .

Congratulations, your beetle robot is done!
If you liked this tutorial, please vote for it! Tell your friends to check it out.
There is nothing more motivating then knowing that 57 000 people visited my instructables! This stimulates me to make more tutorials! and more reading for you...

Thanks for reading!

Jerome Demers
Sherbrooke, Quebec, Canada

ps- Don't forget to vote! :P

Here are statistic to know a little about how I made this instructable.

It took me 5 hours to make this instructable. This is without counting the photography. I would say a good 5 hours to take the pictures.

Here is how I took my pictures. I took some CFL lamp cool white. Since daylight are hard to find.

I took some cheap lamp holder and had 3 lamps while taking pictures.
I had this big white plastic that was on my on my desk. I even took a mirror on the back so I could not lose any light.

I use a Sony DSC-W1 and it was set to macro. The other secret is the to set the camera to fluorescent lighting instead of automatic setting.

Every pictures of this and all my instructables are copyright. You have no right to copy my files without asking. I have found a video on youtube of my tutorial with my pictures and my name was not there! I have contacted the user and he modify his video.

If people use my files without asking, I will simply remove and stop making instructables.
It does not mean you find in it on the internet it is yours.

Thanks mom for proof reading! :D

'"Copyright 2008 by Jerome Demers"'