An hexapod is a mechanical device that walks on six legs. Since a robot is more stable on three or more legs, an hexapod has a great deal of flexibility in how it can move. If some legs become disabled, the robot may still be able to walk. Furthermore, not all of the robot's legs are needed for stability; other legs are free to reach new foot placements or manipulate a payload.
Hexapod Simulation
Choosing an Hexapod: Money, The Sinews of War
When you are looking for an Hexapod kit, you soon realize that it is very difficult to stay below 1.000,00 € and personally this kind of amount is, at the bare minimum, non negligible. On the other hand, hexapods are quite appealing, either technically or visually (I mean that these bots are really freaking cool) so I looked for more affordable solutions.
If a problem is complex, one must decompose it into simpler problems
An Hexapod consists of three main parts, the chassis (the mechanical part), the controller (the electronic part), and the servo-motors (the motorization). The idea being here to find the better price/performance for each part.
A. The Chassis.
I retained 3 chassis which seem interesting for their price and the fact that they are all 3 DOF kits.
A1. MSR-H01 Hexapod Robot Kit from MicroMagic Systems. The favorite.
The MSR-H01 is a 3 DOF hexapod kit consisting of 26 aluminum body and leg components in one of three anodized colors, Silver, Red or Black. The kit comes with all screws, stand-offs, nuts and bolts for assembly.
There are mounting holes on the top body plate for the controllers. With the controler mounted inside the body, there is plenty of room on top of the body for a 5 cell AA battery pack and additional electronics. This kit has been designed to fit the karbonite gear HS-65HB servo from Hitec. It is also possible to use the HS-65MG version.
This kit is worth around 65.00 € and can be ordered at Microsystem Magic . The chassis is really not expensive, one could nearly argue that it is not expensive enough. As you will see later, controler and servor-motors also represent a important part of the final budget. It is maybe not that a good idea to buy such a low cost chassis.
A3. The Phoenix Hexapod. The expensive
The Phoenix Hexapod Robot has a design very similar to the MSR-H01 (see above) or vice versa. The robot has been designed to use 18 Hitec HS-645 servos for the legs. The kit includes everything you need to build the robot mechanics
with the exception of 6 x ASB-04 pairs (Servo Bracket).
The kit is worth between 260.00 and 300.00 € depending where you order it and if you include aluminium servo brackets. it can be ordered in different online stores (LynxMotion, RobotShop, NoDna,...Google is your friend)
B. The Controller
The controller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Controllers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.
B1. MondoMatrix
MondoMatrix is an easy to use open hardware platform. The MondoMatrix system is controlled by a main controller, the Displayduino controller which is like the popular Arduino controller except Displayduino controllers can connect to MondoMatrix expansion boards and are able to control up to 64 servo motors.
Displayduino works exactly like Arduino and uses the Arduino Programming Language. This means that programming the Displayduino microcontroller is the same as programming an Arduino Microcontroller. Displayduino Arduino Adapter fit right on top of any Displayduino main controller. It allows Displayduino users to take advantage of the ever expanding Arduino Shields by simply plugging them in.
ServoMatrix is a MondoMatrix expansion board that can control up to 64 Servo Motors. Each servo can have positions between 0 and just over 200. One of the most powerful features of ServoMatrix is that you can have up to 8 different kinds of servos controlled by a single board. The reason is that each row of eight servos has an independent power port. All of the power servo ports can be connected to one power source or each row of eight servos can have independent power sources.
The motherboard with the ServoMatrix and the Arduino Adapter will cost you a maximum of 220.00 €.
More information about MondoMatrix - DisplayDuino - ServoMatrix HERE
B2. Fez Domino - SSC-32 servo controller
The FEZ domino is a tiny open source board running Microsoft .NET Micro Framework. This means, you can write code with much more efficiency using C# programming language under free Microsoft Visual C# express. Many libraries are already included like FAT file system, threading, UART, SPI, I2C, GPIO, PWM, ADC, DAC and many more.
You can see that FEZ Domino's outline looks similar to Arduino Uno / Duemilanove. The reason for this compatibility is that many shields already exist for the Arduino board. TinyCLR.com offers several shields (Ethernet, Display, Motor Driver, etc.) that are fully tested and supported with FEZ Domino. Furthermore, with the FEZ Domino Expansion shield and onboard extension header, the user can easily add extensions and components. This allows FEZ Domino to remain simple yet extremely flexible. 
B3. Pico-ITX PC Board.
Hexapod Simulation
Choosing an Hexapod: Money, The Sinews of War
When you are looking for an Hexapod kit, you soon realize that it is very difficult to stay below 1.000,00 € and personally this kind of amount is, at the bare minimum, non negligible. On the other hand, hexapods are quite appealing, either technically or visually (I mean that these bots are really freaking cool) so I looked for more affordable solutions.
If a problem is complex, one must decompose it into simpler problems
An Hexapod consists of three main parts, the chassis (the mechanical part), the controller (the electronic part), and the servo-motors (the motorization). The idea being here to find the better price/performance for each part.
A. The Chassis.
I retained 3 chassis which seem interesting for their price and the fact that they are all 3 DOF kits.
A1. MSR-H01 Hexapod Robot Kit from MicroMagic Systems. The favorite.
The MSR-H01 is a 3 DOF hexapod kit consisting of 26 aluminum body and leg components in one of three anodized colors, Silver, Red or Black. The kit comes with all screws, stand-offs, nuts and bolts for assembly.
There are mounting holes on the top body plate for the controllers, with the electronics mounted underneath the top body plate, there is still enough room within the body for a 5 cell Sub-C battery pack. At the front of the hexapod there is a servo mounting point for an optional pan/tilt head.
This kit is worth around 145.00 € (which certainly represents a good quality/price ratio) and can be ordered at Microsystem Magic
A2. MSR-µBug Micro Hexapod Robot Kit. The low-cost.
MSR-µBug is a 3 DOF micro sized hexapod kit consisting of 35 acrylic body and leg components including two head options, pan only or pan and gripper, in one of three colours, #34BBE3, white or black. The kit comes with all screws, stand-offs, nuts and bolts for assembly. The µBug measures approximately 240mm long and 190mm wide in its neutral position.
This kit is worth around 65.00 € and can be ordered at Microsystem Magic . The chassis is really not expensive, one could nearly argue that it is not expensive enough. As you will see later, controler and servor-motors also represent a important part of the final budget. It is maybe not that a good idea to buy such a low cost chassis.
A3. The Phoenix Hexapod. The expensive
The Phoenix Hexapod Robot has a design very similar to the MSR-H01 (see above) or vice versa. The robot has been designed to use 18 Hitec HS-645 servos for the legs. The kit includes everything you need to build the robot mechanics
with the exception of 6 x ASB-04 pairs (Servo Bracket).
The robot is made from T6 aluminum components that are either bright dip Blue or Red anodized or jet black anodized. The Tibia and Femur parts are made from 0.125" thick material, and the chassis parts are made from 0.063" thick material.
The kit is worth between 260.00 and 300.00 € depending where you order it and if you include aluminium servo brackets. it can be ordered in different online stores (LynxMotion, RobotShop, NoDna,...Google is your friend)
B. The Controller
The controller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Controllers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.
B1. MondoMatrix
MondoMatrix is an easy to use open hardware platform. The MondoMatrix system is controlled by a main controller, the Displayduino controller which is like the popular Arduino controller except Displayduino controllers can connect to MondoMatrix expansion boards and are able to control up to 64 servo motors.
Displayduino works exactly like Arduino and uses the Arduino Programming Language. This means that programming the Displayduino microcontroller is the same as programming an Arduino Microcontroller. Displayduino Arduino Adapter fit right on top of any Displayduino main controller. It allows Displayduino users to take advantage of the ever expanding Arduino Shields by simply plugging them in.
DisplayDuino Motherboard
The ServoMatrix
ServoMatrix is a MondoMatrix expansion board that can control up to 64 Servo Motors. Each servo can have positions between 0 and just over 200. One of the most powerful features of ServoMatrix is that you can have up to 8 different kinds of servos controlled by a single board. The reason is that each row of eight servos has an independent power port. All of the power servo ports can be connected to one power source or each row of eight servos can have independent power sources.
The motherboard with the ServoMatrix and the Arduino Adapter will cost you a maximum of 220.00 €.
More information about MondoMatrix - DisplayDuino - ServoMatrix HERE
B2. Fez Domino - SSC-32 servo controller
The FEZ domino is a tiny open source board running Microsoft .NET Micro Framework. This means, you can write code with much more efficiency using C# programming language under free Microsoft Visual C# express. Many libraries are already included like FAT file system, threading, UART, SPI, I2C, GPIO, PWM, ADC, DAC and many more.
You can see that FEZ Domino's outline looks similar to Arduino Uno / Duemilanove. The reason for this compatibility is that many shields already exist for the Arduino board. TinyCLR.com offers several shields (Ethernet, Display, Motor Driver, etc.) that are fully tested and supported with FEZ Domino. Furthermore, with the FEZ Domino Expansion shield and onboard extension header, the user can easily add extensions and components. This allows FEZ Domino to remain simple yet extremely flexible.
Not to forget that FEZ Domino has extra 8 IOs at the UEXT connector and the USB host, USB device, SD card are all connected directly to the processor and so using those will not reduce your free IO count. Note that all digital/analog pins, PWM, COM1 and SPI are in the same place, other peripherals can be different. For example FEZ Domino provides three serial ports that are available for developers. Arduino only has one and it is used for debugging
The FEZ Domino
SSC-32 Controller
This servo controller has 32 channels of 1uS resolution servo control, including bidirectional communication with query commands, synchronized, or "group" moves. It is weel documented and many tutorials exist on the Internet. This controller can control 32 servos over just 1 serial line (TTL or USB-serial).
The FEZ Domino and the SSC-32 controller will cost you around 100.00 €
B3. Pico-ITX PC Board.
A Pico-ITX is a PC motherboard form factor introduced by VIA Technologies in January 2007. The Pico-ITX form factor specifications call for the board to be 10 x 7.2 cm (3.9 x 2.8 in) , which is half the area of Nano-ITX. The processor can be a VIA C7, a VIA Eden V4, a VIA Nano, Intel Atom, AMD Geode... or any other that uses VIA's NanoBGA2 technology for speeds up to 1.5 GHz, with 128KB L1 & L2 caches. It uses DDR2 400/533 SO-DIMM memory, with support for up to 1GB. Video is supplied via AGP by VIA's UniChrome Pro II GPU with built-in MPEG-2, 4, and WMV9 decoding acceleration.
There are many solutions available on the market, one example here: the PICO820-Z530.
These boards range from 300.00 € to ....Steatite Embedded seems to offer a large range of products but a lot of other e-shops are present on Internet.
Of course, even with such board, you will still need a SSC-32 controller (or equivalent) which make the global "controller" budget around 450.00 €, but at this price you get a complete PC running windows XP or Linuxembedded in your hexapod. This open very interesting possibilities when it comes to software development.
B4. Just another two options, the Roboard RB-100 and the Fox Board G20
They are certainly worth the click to their respective page...Roboard RB-100 seems a little bit expensive, but theFox Board just looks like a winner, especially if you like Linux.
C. The RC Servo-Motors
RC servos are composed of an electric motor mechanically linked to a potentiometer. A controller sends Pulse-width modulation (PWM) signals to the servo. The electronics inside the servo translate the width of the pulse into a position. When the servo is commanded to rotate, the motor is powered until the potentiometer reaches the value corresponding to the commanded position.
They are three main properties (except the price) you should pay attention when comparing RC servo:
- Torque: a measurement of the strength of a servo. Torque is determined by multiplying the force acting on the servo arm by the distance from the center of the servo.
- Speed: defined as the minimum amount of time it takes the servo arm to rotate 60 degrees at maximum rated torque
- Material: From nylon to Titanium. Not exactly the same price... ;-))
They are too many product to make a list here.
Just pay attention that in an hexapod, all servo do not bear the same constraints. Other point, you will need at least 18 of them, take you time to seach the right product at the right price. These can easily vary from simple to triple.
Just pay attention that in an hexapod, all servo do not bear the same constraints. Other point, you will need at least 18 of them, take you time to seach the right product at the right price. These can easily vary from simple to triple.
D. Last words...
It already exists a lot of information on internet about such projects. Do not hesitate to search and to search again. Just to help you a little bit, below three projects, one around the Displayduino, one around the FEZ domino and the last one is just a simulation, should give you additional piece of information... 
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