Let's Make Robots!

Rover 5 tracked robot chassis with adjustable clearance

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Chassis_size.jpg195.69 KB
Rover5_Arduino.zip4.11 KB
Vendor's Description: 


Rover 5 is a unique and powerful  tracked chassis designed by OddBot and produced by DAGU.

Specifications:

Motor rated voltage: 7.2V
Motor stall current: 2.5A
Output shaft stall torque: 10Kg/cm
Gearbox ratio: 86.8:1
Speed: 1Km/hr
Encoder type: Quadrature
Encoder resolution: 1000 state changes per 3 wheel rotations

Tips on using the encoders with sample code can be found here: http://letsmakerobots.com/node/24031

Video indoors autonomous: http://v.youku.com/v_show/id_XMjE5NzkwODA0.html
Video outdoors RC mode: http://v.youku.com/v_show/id_XMjIwMTkxODk2.html
Video mecanum wheels:  http://v.youku.com/v_show/id_XMjI2MDAwMDEy.html

Unlike conventional tracked chassis's you can adjust the clearance. Strechy rubber treads maintain tension as the clearance is changed.

The standard chassis comes with two motors and gearboxes. Each gearbox has an optical quadrature encoder with a resolution of 1000 state changes per 3 revolutions of the output shaft (333.33 pulses per revolution).

The chassis can be upgraded to 4 motors and gearboxes with encoders making it ideal for mecanum wheels such as those produced by FINGERTECH.

The chassis is compatible with Pololu's expansion plates for the RP5 chassis. These plates are ideal for mounting hardware on the chassis.

The gearbox angle can be changed in 5 degree increments and adaptors are available allowing standard RC car wheels to be fitted.

Currently we have a PCB designed to allow Arduino development boards (not included) Diecimila, Duemilanove, Nano and Mega to mount easily on the chassis. This PCB includes power supply, motor drivers with current sensing, IR sensors on each corner, 2 small breadboards, a pan/tilt kit with our IR compound eye and a large prototype area under the breadboards where custom circuitry can be fitted.

The photo below and video show the robot using an Arduino Mega which is not part of the kit.

See the attachments for basic dimensions and autonomous sample code.

 

 

 

 

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shonlh's picture

I am looking for connectors for the motors.   My current motor driver just clamps down the wires.  I want to avoid cutting off the current connectors incase I switch things around in the future.  The issue is I need connectors to current connections to avoid this. 

 

 

Thanks

 

 

Shon
OddBot's picture

Jameco sell suitable connectors: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_880271_-1

The Rover 5 just doesn't use the middle pin.

shonlh's picture

I am hoping to use my rover 5 to do the asteroid challenge.  Might be a little difficult since t can throws the track if I add to much weight but we will see.  

Hi! I've been working with some very simple robot kits and Arduino and I've been disappointed by the quality of the servos. In most of the servos I tested, the control values are very innacurate and differ (sometimes with a large difference) from a servo to another. When I say servo I mean a continuous-360 servo, connected directly to an Arduino board and controlled with Servo.write(90) to stop, 90+ to move forward and 90- to move backward.

How does the motors from this kit work? I see they have encoders, which already is an advance. But are they 'weird' like those ones I mentioned? Is it hard to rely on them to move straight precisely?

Thanks a lot! Looking forward to buying Rover 5! 

OddBot's picture

Continuous rotation servos built from analog servos are not very precise because the analog circuitry is affected by temperature and a potentiometer which is not accurate and of which no two are the same.

The Rover 5 does not include control circuitry. It is just geared motors with a quadrature encoder on the second gear. The photo below shows the older IR quadrature encoder. The new Rover 5 chassis's use two hall-effect sensors and an 8 pole magnet instead but the resolution is the same.

This gives you much more precise control of speed and position but you need a suitable "H" bridge to drive each motor and more complex code.

The 4ch motor controller from DAGU is designed for these motors and include a Quad XOR gate so that 1 external interrupt pin can monitor the two input from an encoder.

Read more about the controller here: letsmakerobots.com/node/25865

That was very helpful! Thanks a lot!

What would youu say teh reccomended payload would be for this chassis?

OddBot's picture

This chassis was not really designed for heavy payloads. The tracks will peel off when you turn with a heavy load.

What are the specs for the wheels so I could replace with traditional wheels? I can find these wheels at any local hobby shop? Thanks.

Dorifto_Shoes's picture

Can someone link me to a place that sells the wheel adapter kit?  I can't seem to find it anywhere...also, where could I get some wheels like the monster truck ones in the pic?

Thanks guys...