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Zapp Bot Small Tank-Tread Robot

Navigates around via ultrasound

The Zapp Bot Small Tank-Tread Robot.

It is a Dual Processor, Double Wide, Tracked Robot.

On Oct 1, 2011 this Robot is featured at http://www.limoncellodigital.com/

Below is a list of parts as currently built:
(The parts list will be updated as the build progresses)

2 - BOE-BOT Chassis
1 - BOE-BOT Tank Track Kit
2 - Parallax (Futaba) Continuous Rotation Servo
1 - Board of Education Basic Stamp USB Board
1 - Basic Stamp 2 HomeWork Board
1 - Ping Ultrasonic Distance Measurement Sensor
1 - Multi-Purpose Sensor Housing (Mounting Bracket) (Lynxmotion)
1 - Pan and Tilt Kit (Black Anodized) (Lynxotion)
2 - Hitec HS-322HD Standard Heavy Duty Servo
2 - Universal Mounting Bracket (Parallax)
1 - 2 x 16 Serial LCD Display
4 - “L” shaped mounting bracket (Parallax)
1 - Servo Extension Cable
1 - Sensirion Temperature/Humidity Sensor
1 - Memsic 2125 Dual-axis Accelerometer
1 - 470 Ohm Resistor
1 - Red LED
1 - Green LED
2 - Light Sensitive Photo Resistors
4 - 220 Ohm Resistors
1 - (RadioShack) True Energy 9.6V/1600mAh Ni-MH RC Car Battery/Charger Combo
1/2 - (RadioShack) RC 9.6V Battery Pack Connector Repair Kit (using the 1/2 that mates to the above battery)
1 - 2.1mm Power Plug (Spliced to the above listed battery pack connector)

I built this as as practice platform, for a larger tracked robot I have been acquiring parts for, but that is another story. 

It has been powered up with some simple BS2 code, that makes the robot go forward backwards and turn.

It has only been run with some really simple BS2 Stamp Code, as shown on the Boe-Bot Tank Tread Kit Documentation.

The Morning of December 27th, 2010 I found a link to the Penguin Robot Society Site, and found this page ABBot: Advanced Boe Bot.

I found this page after I built my Robot, the hardware used is almost identical to what I assembled, so I am adapting this code for use on my robot.

To do this I added a BS2 HomeWork board in place of the the Propeller Demo Board shown in the pictures.

As of Jan 1, 2011, I have loaded the appropriate ABBot: Advanced Boe Bot code into the BOE and homework boards and I have started to modify the code. The ABBot used an EMIC Text-to-Speech Module with I don't have so I have remarked out the related code. In the future I might use a Propeller Board to enable the speech functions.

The Brain or CNS (Central Nervous System) code is loaded on the Homework Board.
The Body or PNS (Peripheral Nervous System) code is loaded on the BOE Board.

As of Jan 2, 2011, the operation of the following hardware has been checked out:
Left and Right Servo Motors
Ping Pan Servo
Ping Sensor
Temperature / Humidity Sensor
Dual Axis Accelerometer
Left and Right Photo Sensors.
Red and Green LEDs

Added rechargeable battery on 1/9/2011, got tired of replacing AA batteries.
Here is a tip to anyone using a BS2 BOE-BOT: Low battery voltage will make your BOT act strangely.

As of 1/9/2011 the BOT is pretty much functional, It can be set to roam and seek light or avoid light. It uses it servo mounted Ping sensor to avoid most obstacles.

Left Side of Robot

Back Side of Robot

Right Side of Robot

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On October 1, 2011 my Zapp-Bot Tank-Tread Robot is featured at http://www.limoncellodigital.com/

Visit my ZappBot website at http://wp.me/P1TpPu-2



 I have all the stuff to start on the prop, but no time to learn a new language right now. I have 2 robots designed for either the prop or any other microcontroller. I mostly use the stamp for now and learned some of it's limitations. Now moving to XBee remote programming. I was thinking of learning the prop 12 blocks system. It seems much easier. I am no programming wiz. Check out my Hybred Boe Bot and 3 servo robotic pkatform on this site. I also have a Crazy Rabbit's Home Robotics page on facebook. I also hop into the Parallax forum now and then. They are great and help me alot when I get stuck. Parallax has great support.

Hi Zappman

I'm happy to see that my ABBOT project has been useful for you as a starting point for your new robot. The main difference is that you have put the two boards horizontally, while I had assembled them vertically. I suspect that your robot is more stable than mine, but it might have some issues in moving through narrow places.

During the next months I am planning to build a new version, which will have a gripper and a voice recognition module. I will keep you informed here about this further development..

As crazyrabbit suggested, you should post this project in the parallax forum too. When I posted mine, it generated some useful discussions and suggestions: http://forums.parallax.com/showthread.php?110211


Hi vrossi,

Thanks for commenting on my ZappBOT Tank-Tread Robot and sharing your ABBOT code.

Yes, I agree with you and crazyrabbit, that I should make a post about my robot on the Parllax forums.

I don't think I ever saw your post http://forums.parallax.com/showthread.php?110211 before, its always been so hard to find thiings at the Parallax forums.

Have you started using the Propeller Chip yet? I find it very powerfull and easy to use for robots.



 Very creative. I am also a Parallax fan. I reciently got a used Boe with treads. I am not so impressed with the treads, but rebuilt them. I had to space the wheels with 2 washers for better alignment with the servo gear. I also added a small bracket on the back wheel that pivits to ajust tension. Now it works fine. Found they never work good on carpet. Nice design. I have several robots on this site, but like the Boe Bot chasses to build from for a small robot. Easy to add things without drilling holes. Just add lexan platforms or bread boards with erector set hardware and or spacers. You should show it off in the Parallax forum. It would get more attention there.

This community pays off once more! Brilliant minds working together is all it takes. Glad you solved your problem. You don´t need to take a picture of it. But thanks for offering.

If you do take the treads off, be sure to lay them straight and not twisted. A twisted tread takes forever to adopt it´s old form. Trust me!


Hey Zappman,

I like your approach. Good work!

Do you have any type of slippage problem considering the location of the sprocket wheel? It seems to me that it doesn´t contact THAT much with the treads...

Good luck!


Hi Andrés,

Yes, the robot has a problem with slippage.

When I built the robot a while back the tracks worked pretty good, the robot could climb over small obstacles, with no problems.

However, when I took the robot out of its storage box after months of storage, to make the video, I found the robot had been banged up a bit, and the tracks now pop of the sprockets more than I like.

I did not design the location of the wheels / sprockets, I purchased a tank-tread kit from Parallax designed to fit their BOE-BOT. There is no place to make adjustments to tighten the treads as part of their kit. I do have a spare tank-tread kit and may use some of those parts to try to tighen up the tracks on my robot.



Hi Andrés,

I just made a quick modification to the robot. I replaced the pair of small wheels on front of the robot with larger wheels (the same size as on the pair on the back of the robot). With this modification I have to stretch the tracks to make them fit on the robot. The tracks now fit much tighter and are not slipping. I think I will pull the rubber tracks off the robot when not in use, so the tracks don't get permanently stretched. I don't have time to take a picture of the change today.



Too bad. That is the one thing I don´t like about off the shelves products. Their ability to grow with you is limited. Sure, they get you up to speed in no time. That is one of the reasons I try to build everything myself. But yes, progress is very slow and painstaking.

You can try to shorten the length of the tread to make sure it doesn´t slip. Maybe swapping one of the sections with a shorter one... if possible.

Good luck!