How to Build a Robot - The BeetleBot

 by robomaniac
Featured
Welcome!

I have been in robotics since I was a kid and I am very passionate by robotics. I learn BEAM robotics around 1997-98 and started building robots for a science faire project call "Insectroides" in 2001. http://robomaniac.solarbotics.net ( they change server and the website links does not work anymore it is on Linux and it is CASE SeNsiTIve! ) here is the old one
http://members.tripod.com/robomaniac_2001/index.htm

One of my many robots was the beetle robot, a VERY simple robot that can avoid obstacles on the floor without ANY silicon chip! ( the red ladybug, second picture, is my FIRST beetlerobot )
the red ladybug use a home made PCB carve with a dremel and two playstation motors with rubber wheel from a walkman!

- NO PROGRAMMING
- NO ELECTRONIC COMPONENT

It use
2 - motors
2 - SPDT switch
1 - AA battery holder

I has 16 years old when my uncle showed me the principal of the SPDT switch ( Simple Pole Double Throw). I then took this idea and incorporated the design into the (world famous) beetle robot :P

Now I am 22 and want to show you step by step instructions how YOU can make this simple robot!

here are some videos of my beetlerobot in action!

The beetlerobot in the video is made using a Printed Circuit Board ( PCB ).
This design will be use if I make a kit one day!






Check them all out here!
http://www.youtube.com/jeromedemers

This Instructable is divided into three parts

- You will learn how to build the robot
- I will explain how the robot works
- I will then teach you how to fix your robot if it does not work ( Debugging )

Don't forget to read the complete tutorial before starting! And remember to wear safety glasses at all time because eye injuries ain't worth the risk! It will happen in a blick of an eye.

Have a great time!

ps- Check out Gareth Branwyn book, I made a one motor walker and he made a complete chapter with my robot!! He send me the book call " Absolute beginner's guide to building robots" A very great book!

Maybe I should write a book...

Jerome Demers aka ROBOMANIAC!

Updated july 2007 - I have added some pictures of the inside of my first beetlerobot. Home made AAA battery holder! I have also added some videos on youtube! http://www.youtube.com/jeromedemers

Updated 22 july 2007 - I added a picture and text on step 19 if your robot does not work :P

Step 1: All the parts you need

MVC-017F.JPG
Here ar the parts you will need:

the robot parts'
2 - 1,5V motors
2 - SPDT switchs mechanically easy to trigger
2 - AA battery
1 - AA battery holder
1 - plastic or wooden pearl
1 - heat shrink that will fit over the motor shaft

This might cost you less then 10$ cdn.
1,98$ for both motors
1$ for the battery holder
1,98$ for both SPDT switchs
ok ok maybe 10$ is a lot!

I like to buy my stuff here
http://www.solarbotics.com/
http://allelectronics.com/
http://www.goldmine-elec.com/default.htm
http://www.bgmicro.com/

If you recycle 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 super good motors, the one that makes the laser move.

the tool to complet the robot
1 - safety glasses
1 - soldering iron
1 - glue gun
1 - wire strippers
1 - side cutter
1 - scissors, knife, x-acto, etc

You need some 1,5Volts motor, not 3V or no event 12V!!
Each motors are powered by a SINGLE AA battery! You will draining your battery if you use 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 SPDT swiths need to be really sensitive! I have order some the order day that where to hard to activated, that might cause some problems and the robot might not even avoid obstacles but rather hug them until death. These swiths 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

You should check http://www.solarbotics.com for some great motors. They even have a SPDT switch in store! I have never tried them but Grant did.

Here is a picture of the Solarbotics switchs in use. The beetlerobot was build by Grant McKee, the engineer for Solarbotics but currently works for WOWWEE in Hongkong ( poor Grant! :P)

http://grant.solarbotics.net/images/MISC/Beetle_bot-IMG_3138.jpg

http://grant.solarbotics.net/Misc.htm

Step 2: Preparing the parts

MVC-018F.JPG
Cut 13 pieces of 2,5inch long electric wire.

ps- cut 14 if you are supertisious.

Step 3: Preparing the parts

MVC-019F.JPG
Now just remove around 1cm to each extremity of the wire.

In other word, strip the wire at both end.

That is 0.3935 inch to be precise.

After that you need to thin the end of each wire with your soldering iron.
Oups, I forgot to tell you to plug your soldering iron, HAHA you need to wait now!

sorry...


Step 4: Group picture

MVC-020F.JPG
Here is everything you need to start building

ok ok I forgot the paperclips and ... what else?

MUWAHAHAHA!

Step 5: Start soldering

MVC-021F.JPG
solder each wire to your parts.

Step 6: The famous third connection

MVC-025F.JPG
MVC-024F.JPG
MVC-023F.JPG
MVC-026F.JPG
Here is the principal and most important thing about the beetlerobot.

It is call the "third connection"

In you AA 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.
I solder a 2 inch long blue wire.


simple hey!

don't forget to browse the other pictures to see.

Step 7: Glueing switchs

Glue your switchs on the battery holder in a V shape.

Don't forget to put the blue "third connection" wire in front.

I have found a much more efficient way to but the switchs on the battery holder.
You can glue them in a A shape so both antenna cross and will not get stuck in a leg chair.

Step 8: Glueing the motors

MVC-035F_motor_direction.JPG
MVC-033F.JPG
motor_angle.gif
Glue both motors on the battery holder

Make sure they spin forward...

I have just realise that this does not make any sense at all! :P

Look at the third picture how you can angle out the motors for speed.

Step 9: The back caster

MVC-037F.JPG
MVC-041F.JPG
MVC-038F.JPG
MVC-039F.JPG
Here you are going to make the third wheel, the back caster using a plastic or wooden pearl.

You can make something fancy or very simple. I took the BIG paperclip.

If you can not find a wooden pearl, you can use the paperclip directly on the floor. It will work but might catch on stuff while rolling around.

Step 11: The antenna!

MVC-049F.JPG
MVC-050F.JPG
You are going to give your little robot some way to feel the world.

Take the small paperclip and bend them to form some antenna.


Glue them on the metal plate pf the SPDT switchs.

I don't recommend soldering them because you need some aggressive acid-based flux or silver solder. If you don't have any experience in soldering, you will melt them.

I have already solder some using silver solder.

Step 13: FINISH!

CONGRADULATION!

You made you first Beetlerobot!

Cross your finger, put the AA into the battery holder and but the robot on the floor...

Does it work?

to stop it, you can step on it or simply remove the battery.

You can add some decoration to the robot. I took some big plastic shell find in the 2$ vending machine. I took one half and added sticker!

to debug the robot go to my website
http://beetlerobot.solarbotics.net/debug.htm
It is in French and you will understand. You made a robot, you can read French now! :P

Oui = yes
Non = no
Est ce que les moteurs tourne? = does the motors turn?
Est ce que votre robot avance tout droit? = does it go in a straight line?

ok ok
I have added other steps to explain more about the robot and a also added a debugging section.

Jerome Demers
You can ask questions in French if you want too.

Step 14: How does it work?

interrupteur.gif
motorright.gif
motorleft.gif
http://en.wikipedia.org/wiki/Switchhttp://en.wikipedia.org/wiki/Switch

ps- This robot does not stop the opposite motor when it touch a wall, it REVERSE the opposite motor so the robot will pivote and avoid obstacle the GOOD WAY!

BEAM powered robot will short circuit the opposite motor so the robot will need to push it's way out .

All the drawing where made with PAINT!

Step 15: How does it work? - the motor

motorright.gif
motorleft.gif
ok this is simple

The electric motor spin when you apply electricity to it. It will spin clockwise and anti-clockwise when you swap the polarity.

If the robot spin in circle after installing the battery, swap the connection of the reversing motor.

http://en.wikipedia.org/wiki/Electric_motor

Step 17: How does it work? - the motor and the switch part 2

foncti3.gif
foncti2.gif
Here you can see what happen when electricity flow through the circuit. Check the second picture.

So you can see that one battery will power BOTH motor when the robot run around your house.

The second battery is only to reverse the beetlerobot when it get stuck. SO this battery will last longer!!

Swap the battery to prolong your battery life and also the robot life.

If the opposite motor does not spin, this mean that you might have a weak battery or simply that the third connection is not working right.

Step 18: Debugging

MVC-679F.JPG
MVC-677F.JPG
I hope your cat is going crazy with the robot... maybe your dog?

Does your robot go in a straight line?
Here is a quick fix.

If the robot start rolling in circle you can add a "blob" of glue to the weak motor.

To know the weak motor, simply put the robot on the floor... if it goes to the left add some glue on the left motor. This will make a bigger shaft and makes the left side travel a longer distance and correct the path of the robot.

It does not mean that you motor is weak, it could just be the angle of your motor.

Step 19: Any questions?

fiba.JPG
I hope everythings work's perfectly for you, if no, ask your questions here!

I took a picture of a special page from the wonderful book Junkbots, Bugbots, and Bots on Wheels by Dave Hrynkiw and Mark Tilden!

Mike Trzecieski wrote that back in 2001 at the Eastern Canadian Robot Games! I got my entire book signed by great roboticist! :D

I got Dave Hrynkiw, Grant McKee, Dave Simmons and his son Kyle Simmons, Scotty Dogma, Ori Barbut, Mike Trzecieski and Richard Weait the creator of the miniball... humm.. do you wonder what is a miniball? Do you want a instructable? :D LOLL

I am missing Mark Tilden signature!!!

Have a great day!

Jerome Demers
Quebec, Canada
1-40 of 506Next »
hussein1 says: Nov 15, 2011. 8:07 AM
hey man can i use an mouse spdt switch?? please reply on this site please.
jwoo2023 in reply to hussein1Dec 30, 2012. 5:07 PM
1 year old reply -.-'
The mouse SPDT would be hard to use, you have to de-solder, and the switch doesn't have an actuator lever (The metal thingy). But it could work! You could hot glue the paper clip on, that's what i tried to do, It fell off after the bot hit a wall 3x
CarlyAnne7 says: Jun 3, 2012. 2:32 PM
Can I Just Buy One From You ?
jwoo2023 in reply to CarlyAnne7Dec 30, 2012. 5:03 PM
You can buy one from Solarbotics now!
Solarbotics Beetle Bot
meghams says: Dec 22, 2012. 2:29 AM
hey very nice bot ..!!wanna try right away ...but one thing which is boggling my mind is how you have fixed those motors in such a inclined angle..??
raghav57 says: Dec 14, 2012. 9:52 PM
i am raghav. i am 12 years old. i got all parts and i made some but how to stick SPDT switches and motors to battery holder.and where can i get heat shrink.the only part i didn't get.where can i get please say
rashtekar says: Nov 3, 2012. 1:53 AM
my bot is not going front when i coneect battries to the motors directly they work properly...but when i connect it to the switch and spdt switches it works slow and doesnt move forward...plz reply....i have to show it on monday..:-(
rashtekar says: Nov 3, 2012. 1:45 AM
my teacher is asking the uses of this beetle bot...what do i tell her????
TANMAYEE says: Oct 20, 2012. 8:42 AM
can u please help with the uses of this beetlebot?? do reply soon. Got an urgency. thank you. :)
Wisaam says: Oct 20, 2012. 6:10 AM
Can you please tell me the actual function of the SPDT switch and how does it work?...Please do reply..
prakash0302 says: Sep 26, 2012. 2:48 AM
hi it's cool idea...........!!!!
indradiana says: Aug 22, 2012. 2:14 AM
can i use two 3 volt motors by only using two 1.5 volt batteries?
does the beetle robot still work normally ?
niljo says: Aug 16, 2012. 7:32 AM
Hi!! i made the beetle robot, bt it wnt wrk if i let go of the switch.. i have to keep it presd..and the funny thng is tat wen i press the spdt swittch on right side, the left motor rotates and vice versa... cud u pls help me wit dis...
robomaniac (author) in reply to niljoAug 16, 2012. 9:16 AM
hello

you are also there.

It is normal that when you press the right switch the left motor spin. That is compltely normal with the Beetle robot V1.

You told me that the robot does not move until you press the switch. This only mean that the third connection is not properly connected to the inside of the battery pack.


When you plug the battery both motors should spin forward. When you press the switch, the opposite motor should turn backward.

Make sure you have a good solder joint, a clean one with no flux or dirty thing on it.
niljo in reply to robomaniacAug 18, 2012. 12:05 AM
hey thnks.. it really helped.. nw ts wrkng no prblm... thnks a lot jerome :)
niljo says: Aug 16, 2012. 7:50 AM
these are sm pics of the beetlebot i made.. i even made the third connection.. it wud very helpful fr me if u assissted me wit dis.. and my email id is niljos22@gmail.com
16082012351.jpg16082012350.jpg16082012353.jpg16082012356.jpg16082012357.jpg
biocon77 says: May 10, 2012. 4:46 PM
can i use a Illuminated round rocker spdt switch?
robomaniac (author) in reply to biocon77May 10, 2012. 5:07 PM
well not really, only if you find an innovating way to trigger the swt with the antenna. then that will work. Rocket swt are stiff (hard to activate) so you need help with a lever system.
biocon77 in reply to robomaniacMay 21, 2012. 5:38 PM
thanks also, can i use jumper wires
biocon77 says: May 20, 2012. 3:54 PM
do jumper wires work?
rimo says: May 10, 2012. 3:32 PM
it works ty sir
xXYEIROXx says: Feb 18, 2012. 8:04 PM
Hi there, i Did it! it works xDD ok to the grain, i wanna make one for one scientific faire in my high school but i wanna make it with an solar panel, so i dont see where i can put a thirth conection, if you know how plz make me know!
shadabd.kvdwd says: Feb 11, 2012. 6:21 AM
when my robot touches to a wall ,the switch will press till this process the robot is ok but after that the motor do not have that much force to push can you tell me what is problem...

reply at meetshadabmk@yahoo.com......pleaseeeeeeeeeeeeeeeeee
Yaryev says: Feb 4, 2012. 11:41 PM
Hello, my son really likes science projects, is in third grade. How or where do you recommend I can find information for my child to start learning about robotics? thanks
rnoorlind says: Jul 5, 2011. 9:30 AM
Thanks to this tutorial I got few burns :p from soldering iron and glue gun but I finished my robot. Although the wiring pic wasn't very helpful as with my robot I had one wire on every thinkable nob but the instructing pic had one wire about two wires. At that part things got messed up. So all was able to do was to sketch circuits until I understood it. But I thank you for making me think it through like that.
Thank you!
rajaavadi says: Jul 3, 2011. 12:41 AM
Where does that blue wire from motor go?
d'où vient le fil bleu aller?
aabuzaid says: Jun 30, 2011. 10:07 AM
hi how are you ,,, there are anyone can help me to built robot ,,,, i am studing mechatronics and there are project for robot course ,, my project is wowwee robotpet robot
kkeyan says: Jun 27, 2011. 7:26 AM
hey dude it is realllllly intrestinggggggggggggggg
rnoorlind says: Jun 25, 2011. 5:05 AM
At least the picture has metric system.
jsharma4 says: Jun 24, 2011. 1:45 AM
can i use spdt switch found in mouse fr d robot model?????????
plz reply fast..........i've 2 submmit my robo on 28 th
ashuki says: Jun 5, 2011. 9:28 AM
can you give me the schematic diagram ?

rkittukriti says: Jun 3, 2011. 6:35 PM
hey can i use it for my biology project!!??
rmkn21 says: May 25, 2011. 12:46 AM
In legazpi city, spdt limit switch is called micro switch
gpunia says: May 16, 2011. 2:41 AM
can you help me make a SPDT switch from house things pleaseeeeeeeeeeeee
and if you know please send me at punia.gaurav5@gmail.com
sanjo shaju says: May 20, 2010. 10:32 PM
can u help me to make a SPDT switch by using home thing!!!!!!!!!!

i will be very glad if you help me pleeeeeeeeeeeeeeeeeeese..........

                                              /       *           *      \
                                              !             J             !
                                                \        -------       /


IT BITz in reply to sanjo shajuMay 13, 2011. 1:07 AM
Hai the above one is me
alzrc_13j in reply to sanjo shajuFeb 9, 2011. 10:13 PM
go chop some old pc mouse....u can find it there...that is what i used for my beetle bot.....just be careful not to toast the switches hehehe
kabshab77 says: Mar 3, 2011. 6:43 PM
what does solder mean?
pudgytaco in reply to kabshab77Apr 10, 2011. 2:20 PM
Soldering is defined as "the joining of metals by a fusion of alloys which have relatively low melting points". In other words, you use a metal that has a low melting point to adhere the surfaces to be soldered together. Consider that soldering is more like gluing with molten metal, unlike welding where the base metals are actually melted and combined. Soldering is also a must have skill for all sorts of electrical and electronics work. It is also a skill that must be taught correctly and developed with practice. from http://www.aaroncake.net/electronics/solder.htm
101nemesis says: Apr 3, 2011. 9:15 AM
I've made the robot..but when i press the swtich..the opposite motor STOPS . It doesn't reverse its direction !
What could be the reason ??
1-40 of 506Next »
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