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What this is:
This instructable will show you how to make your Arduino into an R/C interface that you can use for just about anything requiring remote control. I will also show you how I built an R/C lawnmower using my Arduino, a cheap R/C transmitter and receiver pair, and a couple of electric-wheelchair motors from Ebay. I have used this interface to control anything from basic LED's to Bipolar stepper motors, mini-robots, lifeless R/C cars from the thrift store, and even a 100lb lawnmower (all with appropriate motor controllers). It is very flexible and easy to change and very simple to set up.
See a slightly different version of the Lawnbot400 in my new book "Arduino Robotics" , as well as a DIY Segway and several other bots.
Check it out in MAKE magazine in the April 2010 issue (#22) or here:
UPDATE 3-24-10
New wheel-barrow bucket mounted on top with hinges so it can dump its contents.
UPDATE 3-10-10: NEW CODE
And new video of the Lawnbot400 moving a bunch of dirt from my truck to the flower beds across the yard, also I updated the code again.
.
I added some new code to the project that is safer, including a manual kill-switch and a Failsafe switch.
To implement the Failsafe, I used another Atmega168 (or an Arduino), to control a normally-open 60amp power relay. The relay disconnects the power to the motor-controller unless receiving a "good" signal from the 2nd microcontroller. This signal is updated 2 times every second and is either ON or OFF. If the bot gets out of range, it loses power to the motors. If I flip the kill-switch on the Transmitter, it loses power to the motors. This is also a handy way to disable it remotely if anything were to go near it that wasn't supposed to. The updated code for both microcontrollers is on the CODE page.
In addition to the failsafe, I changed the way the code reads the PPM signals to make it more reliable. Also, I realized that I was only able to run the bot at 80% speed with the old code, so now it is quite a bit faster and has more power (it can carry me across the yard @ 155lb).
Check out this new video of me riding the Lawnbot400, my wife driving it over a bunch of branches, then me making do some wheelies. Don't worry, the mower was turned off this time since the grass didn't need cutting, we were just having fun.
Disclaimer:
DANGER!!! This is a VERY dangerous piece of equipment if not handled appropriately. Since all the electronics have been home-built and the Arduino code is new, you MUST be very careful while operating anything heavy with this code. I have had 1 or 2 times during testing - and before adding a secondary failsafe - that the main Arduino jammed up and I temporarily lost control of the mower for a few seconds!!!! Though I have added several filters to discard unwanted signals and I rarely have any issues, an un-manned lawnmower IS STILL A POTENTIAL DEATH TRAP and I assume no responsibility for anything that happens as a result of your use of this code or this tutorial. This is meant as a guide for people who not only have the ability to build such a contraption, but the responsibiltity to operate it safely as well. Any suggestions or ideas on how to make this a safer project is always gladly accepted. Having said that, it's also awesome.
Background:
Most R/C equipment comes packaged for a single specific use, which makes it easy to use but is very limited in what you can do with it. So using the Arduino as an interpreter between the R/C system and the motor driver, I can use any motor controller that I want (depending on the size of the motor and power required), reprogramming the Arduino to supply the required signals.
What I ended up with:
After successfully hacking a few R/C cars from the thrift store, I got bored driving them around the driveway and I was having a hard time convincing my wife that there was any usefulness in the revived toy car. So I decided it was time to make my biggest chore at home, a whole lot easier and actually put my Arduino to work, and thats how I ended up building an R/C lawnmower.
While designing the lawnmower, I thought it would be cool to learn about the electronics that made it move, so I designed and built my own motor speed controller (or H-bridge) to power the lawnmower. I looked around at every H-bridge design I could find before deciding to go with a Mosfet h-bridge that uses both N-channel and P-channel Mosfets.
I built several different motor driver boards for this project, the first two were on Radio-Shack perf-board and the next 4 were designed using EagleCad and etched to a piece of copper-clad PCB, using the toner-transfer method. The most recent board is the one I use to mow the lawn as it has the ability to stay cool even while operating for long periods of time (30-40 mins straight) at 10-20amps and 24vdc. FWIW, I had to burn up a lot of Mosfets to find this out. If you want to see any of my other motor controllers, go to www.rediculouslygoodlooking.com and check out the Mosfet shield.
Here is what I bought already assembled:
FM R/C transmitter and receiver pair from ebay = $40
Arduino = $30
I already had a used push-mower = $60
Here is what I bought and assembled into the Lawnbot400 (as I call it):
(2) electric-wheelchair motors from ebay = $40 ea
(2) 12v marine deep cycle batteries - Walmart - $60 ea new (used batteries might work)
36" pieces of 2" angle-iron (2) and 1" square-tubing (2) from Home Depot = $8 ea
36" pieces of 1" angle-iron (2) and 1" flat steel bar (2) from Home Depot = $5 ea
(a lot) of nuts, bolts, washers, lock washers 3/8" or 1/2" with drill bit = $20
(2) caster wheels from Harbor Freight Tools = $14 ea
(2) drive wheels from Harbor Freight Tools = $8 ea
(36") 5/8" threaded rod with several 5/8" nuts and washers from Home Depot = $8
(2) sprockets from Allelectronics = $5 ea
#25 roller chain and a few universal links from Allelectronics = $10 for 3'
sprockets from Electronics Goldmine = $1.50 ea
(24) mosfets from Digikey = $1 ea
(there were quite a few small parts for building the H-bridge, they are listed later on)
This instructable will show you how to make your Arduino into an R/C interface that you can use for just about anything requiring remote control. I will also show you how I built an R/C lawnmower using my Arduino, a cheap R/C transmitter and receiver pair, and a couple of electric-wheelchair motors from Ebay. I have used this interface to control anything from basic LED's to Bipolar stepper motors, mini-robots, lifeless R/C cars from the thrift store, and even a 100lb lawnmower (all with appropriate motor controllers). It is very flexible and easy to change and very simple to set up.
See a slightly different version of the Lawnbot400 in my new book "Arduino Robotics" , as well as a DIY Segway and several other bots.
Check it out in MAKE magazine in the April 2010 issue (#22) or here:
UPDATE 3-24-10
New wheel-barrow bucket mounted on top with hinges so it can dump its contents.
UPDATE 3-10-10: NEW CODE
And new video of the Lawnbot400 moving a bunch of dirt from my truck to the flower beds across the yard, also I updated the code again.
.
I added some new code to the project that is safer, including a manual kill-switch and a Failsafe switch.
To implement the Failsafe, I used another Atmega168 (or an Arduino), to control a normally-open 60amp power relay. The relay disconnects the power to the motor-controller unless receiving a "good" signal from the 2nd microcontroller. This signal is updated 2 times every second and is either ON or OFF. If the bot gets out of range, it loses power to the motors. If I flip the kill-switch on the Transmitter, it loses power to the motors. This is also a handy way to disable it remotely if anything were to go near it that wasn't supposed to. The updated code for both microcontrollers is on the CODE page.
In addition to the failsafe, I changed the way the code reads the PPM signals to make it more reliable. Also, I realized that I was only able to run the bot at 80% speed with the old code, so now it is quite a bit faster and has more power (it can carry me across the yard @ 155lb).
Check out this new video of me riding the Lawnbot400, my wife driving it over a bunch of branches, then me making do some wheelies. Don't worry, the mower was turned off this time since the grass didn't need cutting, we were just having fun.
Disclaimer:
DANGER!!! This is a VERY dangerous piece of equipment if not handled appropriately. Since all the electronics have been home-built and the Arduino code is new, you MUST be very careful while operating anything heavy with this code. I have had 1 or 2 times during testing - and before adding a secondary failsafe - that the main Arduino jammed up and I temporarily lost control of the mower for a few seconds!!!! Though I have added several filters to discard unwanted signals and I rarely have any issues, an un-manned lawnmower IS STILL A POTENTIAL DEATH TRAP and I assume no responsibility for anything that happens as a result of your use of this code or this tutorial. This is meant as a guide for people who not only have the ability to build such a contraption, but the responsibiltity to operate it safely as well. Any suggestions or ideas on how to make this a safer project is always gladly accepted. Having said that, it's also awesome.
Background:
Most R/C equipment comes packaged for a single specific use, which makes it easy to use but is very limited in what you can do with it. So using the Arduino as an interpreter between the R/C system and the motor driver, I can use any motor controller that I want (depending on the size of the motor and power required), reprogramming the Arduino to supply the required signals.
What I ended up with:
After successfully hacking a few R/C cars from the thrift store, I got bored driving them around the driveway and I was having a hard time convincing my wife that there was any usefulness in the revived toy car. So I decided it was time to make my biggest chore at home, a whole lot easier and actually put my Arduino to work, and thats how I ended up building an R/C lawnmower.
While designing the lawnmower, I thought it would be cool to learn about the electronics that made it move, so I designed and built my own motor speed controller (or H-bridge) to power the lawnmower. I looked around at every H-bridge design I could find before deciding to go with a Mosfet h-bridge that uses both N-channel and P-channel Mosfets.
I built several different motor driver boards for this project, the first two were on Radio-Shack perf-board and the next 4 were designed using EagleCad and etched to a piece of copper-clad PCB, using the toner-transfer method. The most recent board is the one I use to mow the lawn as it has the ability to stay cool even while operating for long periods of time (30-40 mins straight) at 10-20amps and 24vdc. FWIW, I had to burn up a lot of Mosfets to find this out. If you want to see any of my other motor controllers, go to www.rediculouslygoodlooking.com and check out the Mosfet shield.
Here is what I bought already assembled:
FM R/C transmitter and receiver pair from ebay = $40
Arduino = $30
I already had a used push-mower = $60
Here is what I bought and assembled into the Lawnbot400 (as I call it):
(2) electric-wheelchair motors from ebay = $40 ea
(2) 12v marine deep cycle batteries - Walmart - $60 ea new (used batteries might work)
36" pieces of 2" angle-iron (2) and 1" square-tubing (2) from Home Depot = $8 ea
36" pieces of 1" angle-iron (2) and 1" flat steel bar (2) from Home Depot = $5 ea
(a lot) of nuts, bolts, washers, lock washers 3/8" or 1/2" with drill bit = $20
(2) caster wheels from Harbor Freight Tools = $14 ea
(2) drive wheels from Harbor Freight Tools = $8 ea
(36") 5/8" threaded rod with several 5/8" nuts and washers from Home Depot = $8
(2) sprockets from Allelectronics = $5 ea
#25 roller chain and a few universal links from Allelectronics = $10 for 3'
sprockets from Electronics Goldmine = $1.50 ea
(24) mosfets from Digikey = $1 ea
(there were quite a few small parts for building the H-bridge, they are listed later on)
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Signing UpStep 1Setting up
1. Get R/C transmitter and receiver (I have tested FM and AM systems and they both work)
2. Upload code to Arduino (it is on the last page)
3. Make sure you are getting a good signal
You will need an R/C radio transmitter(Tx) and receiver(Rx) pair, which is the most expensive part of the project, but can be used for every future project you might have involving R/C. I went with a 6-channel FM system, but I have tested a 27mHz AM transmitter/receiver and it works just as well. The beauty of the Arduino is that if you want to adjust the deadband or the motor-speed at turn-on, (unlike commercial ESC's) it is all easy changed in the Arduino IDE.
Once you have your radio, all you need to do is upload the code to your Arduino, plug in the 2 channels that you want to use from your radio receiver into Digital pins 2 and 3 of the Arduino (these are the 2 external interrupt pins on the Arduino) and you are ready to control whatever you want. If you don't have a batter pack for the receiver, you can run jumper wires from the Arduino +5v and GND to the R/C receiever for power, you only need to supply a single channel with GND and +5v (it is not necessary to power every channel).
Upload the code using the Aruino IDE (I am using version 0016 on Ubuntu).
I started by controlling 3 LED's with 1 channel on a breadboard. I wired a red LED to be Forward (digital pin 9), a yellow LED for Reverse(digital pin 5), and a green LED for Neutral (digital pin 12). This allows you to adjust the code to fit the needs of your radio system. You will have smooth 0-100% PWM control of both LED's and the neutral light will turn on when the control stick is centered. If needed, you can widen the deadband for Neutral, but doing so will increase the speed at turn-on (which starts at 0%, so that would likely be desirable). See pictures.
----------------------------------------
The code has 4 PWM outputs for motor control:
channel 1 Forward = Arduino digital pin 9
channel 1 Reverse = Arduino digital pin 5
channel 2 Forward = Arduino digital pin 10
channel 2 Reverse = Arduino digital pin 6
2 outputs for Neutral indicator lights:
channel 1 = digital pin 12
channel 2 = digital pin 13
The 2 INPUTS from the R/C receiver should go to:
channel 1 = digital pin 2
channel 2 = digital pin 3
---------------------------------------
If you are interested to see your readings, turn on your Serial Monitor in the Arduino IDE (set to 9600bps) and you can see the actual real-time pulse readings for each channel, they should read:
full forward = 2000 (2 milliseconds)
center = 1500 (1.5 ms)
full reverse = 1000 (1 ms)
These readings reflect the number of microseconds that the pulse signal from the R/C receiver stays HIGH (or at 5v). The typical Servo signal that comes from an R/C receiver is a pulse whose length varies from approximately 1 ms to 2 ms with 1.5 ms being Neutral (which should also be the position that the control stick returns to when you let it go). The transmitter reads the position of the control stick and sends that pulse length about once every 20milliseconds. So it is constantly updating for precise control (for more info, look up PPM on wikipedia). If you push the transmitter control stick forward, the reading should go up to 2000, if you push it backward it should go down to 1000. You can also use a voltage meter at this point to see that Digital Pins 5, 6, 9, & 10 will be changing from 0-5v depending on the position of the control sticks on the R/C transmitter.
If you care to know, the code uses the Arduino's 2 external interrupts to capture when the Rx signal pin changes states (goes from HIGH to LOW or vice versa), when it does at the beginning of each signal, it calls the interrupt function which reads the digital state of the pin and if HIGH, it records the microseconds value on the Arduino system timer0. It then returns to the loop until the pin goes LOW, at which point it subtracts the previously recorded microsecond value from the new current microsecond value to determine how long the pulse stayed HIGH (which tells us the position of the Transmitter control stick). It then does that over and over really fast.
I have the values constrained from 600-2400 in the Arduino code to keep things simple. Once it receives the signal and constrains it, it maps that value to be proportionally between 0 and 511, where 255 will be Neutral. The code then determines when the value changes and uses a function to determine the appropriate 0-255 PWM value in the appropriate direction and each direction has it's own PWM output pin to control the H-bridge.
On a side note:
To make things easier, I built an Arduino-based breakout board using Radio-Shack perf-board, a 28pin DIP socket, a 16mhz oscillator, and a bit of wire. I also added a set of female-headers in such a way that I can plug my R/C receiver directly onto the breakout board. For secure connections while mowing grass, I added screw-terminals on each Output pin and each of the 6 channels from the receiver. It also has a built in 5v regulator to power both the Atmega168 from the Arduino and the R/C receiver (which gets power when you plug it onto the breakout board). So you just route jumper wires from the channels you want to use on the receiver, to the Atmega digital pins 2 and 3. I also added 2 LED lights that are hard wired to the digital pins 12 and 13 for the Neutral lights for each channel so I can easily see when I am in neutral.
Since this bot is a Tank steer setup with 1 drive motor on each wheel, the coding is very straightforward where the left stick controls the left motor and the right stick controls the right motor. Both sticks forward means lawnmower goes straight forward, both backward and it goes in reverse. If you push the left forward and the right backward, it does a zero-turn circle. As you can imagine, mowing the grass is really fun now.
2. Upload code to Arduino (it is on the last page)
3. Make sure you are getting a good signal
You will need an R/C radio transmitter(Tx) and receiver(Rx) pair, which is the most expensive part of the project, but can be used for every future project you might have involving R/C. I went with a 6-channel FM system, but I have tested a 27mHz AM transmitter/receiver and it works just as well. The beauty of the Arduino is that if you want to adjust the deadband or the motor-speed at turn-on, (unlike commercial ESC's) it is all easy changed in the Arduino IDE.
Once you have your radio, all you need to do is upload the code to your Arduino, plug in the 2 channels that you want to use from your radio receiver into Digital pins 2 and 3 of the Arduino (these are the 2 external interrupt pins on the Arduino) and you are ready to control whatever you want. If you don't have a batter pack for the receiver, you can run jumper wires from the Arduino +5v and GND to the R/C receiever for power, you only need to supply a single channel with GND and +5v (it is not necessary to power every channel).
Upload the code using the Aruino IDE (I am using version 0016 on Ubuntu).
I started by controlling 3 LED's with 1 channel on a breadboard. I wired a red LED to be Forward (digital pin 9), a yellow LED for Reverse(digital pin 5), and a green LED for Neutral (digital pin 12). This allows you to adjust the code to fit the needs of your radio system. You will have smooth 0-100% PWM control of both LED's and the neutral light will turn on when the control stick is centered. If needed, you can widen the deadband for Neutral, but doing so will increase the speed at turn-on (which starts at 0%, so that would likely be desirable). See pictures.
----------------------------------------
The code has 4 PWM outputs for motor control:
channel 1 Forward = Arduino digital pin 9
channel 1 Reverse = Arduino digital pin 5
channel 2 Forward = Arduino digital pin 10
channel 2 Reverse = Arduino digital pin 6
2 outputs for Neutral indicator lights:
channel 1 = digital pin 12
channel 2 = digital pin 13
The 2 INPUTS from the R/C receiver should go to:
channel 1 = digital pin 2
channel 2 = digital pin 3
---------------------------------------
If you are interested to see your readings, turn on your Serial Monitor in the Arduino IDE (set to 9600bps) and you can see the actual real-time pulse readings for each channel, they should read:
full forward = 2000 (2 milliseconds)
center = 1500 (1.5 ms)
full reverse = 1000 (1 ms)
These readings reflect the number of microseconds that the pulse signal from the R/C receiver stays HIGH (or at 5v). The typical Servo signal that comes from an R/C receiver is a pulse whose length varies from approximately 1 ms to 2 ms with 1.5 ms being Neutral (which should also be the position that the control stick returns to when you let it go). The transmitter reads the position of the control stick and sends that pulse length about once every 20milliseconds. So it is constantly updating for precise control (for more info, look up PPM on wikipedia). If you push the transmitter control stick forward, the reading should go up to 2000, if you push it backward it should go down to 1000. You can also use a voltage meter at this point to see that Digital Pins 5, 6, 9, & 10 will be changing from 0-5v depending on the position of the control sticks on the R/C transmitter.
If you care to know, the code uses the Arduino's 2 external interrupts to capture when the Rx signal pin changes states (goes from HIGH to LOW or vice versa), when it does at the beginning of each signal, it calls the interrupt function which reads the digital state of the pin and if HIGH, it records the microseconds value on the Arduino system timer0. It then returns to the loop until the pin goes LOW, at which point it subtracts the previously recorded microsecond value from the new current microsecond value to determine how long the pulse stayed HIGH (which tells us the position of the Transmitter control stick). It then does that over and over really fast.
I have the values constrained from 600-2400 in the Arduino code to keep things simple. Once it receives the signal and constrains it, it maps that value to be proportionally between 0 and 511, where 255 will be Neutral. The code then determines when the value changes and uses a function to determine the appropriate 0-255 PWM value in the appropriate direction and each direction has it's own PWM output pin to control the H-bridge.
On a side note:
To make things easier, I built an Arduino-based breakout board using Radio-Shack perf-board, a 28pin DIP socket, a 16mhz oscillator, and a bit of wire. I also added a set of female-headers in such a way that I can plug my R/C receiver directly onto the breakout board. For secure connections while mowing grass, I added screw-terminals on each Output pin and each of the 6 channels from the receiver. It also has a built in 5v regulator to power both the Atmega168 from the Arduino and the R/C receiver (which gets power when you plug it onto the breakout board). So you just route jumper wires from the channels you want to use on the receiver, to the Atmega digital pins 2 and 3. I also added 2 LED lights that are hard wired to the digital pins 12 and 13 for the Neutral lights for each channel so I can easily see when I am in neutral.
Since this bot is a Tank steer setup with 1 drive motor on each wheel, the coding is very straightforward where the left stick controls the left motor and the right stick controls the right motor. Both sticks forward means lawnmower goes straight forward, both backward and it goes in reverse. If you push the left forward and the right backward, it does a zero-turn circle. As you can imagine, mowing the grass is really fun now.
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Thanks for your support, I'm glad you like it! If you have any questions with any of the projects, feel free to shoot me a message.
Regards,
JD
Thanks. David.
well, the Bug-bot uses the built-in motor-controllers in the Servo motors to drive them directly from the Arduino output pins... this is much cheaper and easier to set up if you are using standard hobby Servos, as they usually include built-in controllers. But Linus, uses the servo motor without the internal drive circuitry just like a dc motor with a gearbox - this method requires an external motor-controller which can increase the cost if you have to buy one. Both methods require modifying the output gear to remove the stop piece, so it will allow for continuous rotation. If your servos have no drive circuitry, then they should need no modification, unless they have not yet been modified for continuous rotation.
Thanks Undie.
I was wondering though, what are the main "version" differences between :instructables, Arduino Robotics book, and Make Magazine article? Just curious.
Thanks ... Undie
i want to design a motor drive circuit for driving 2, 5A 22v DC motors. Motors will be used in an electric wheel chair, i also want to control the speed of motors with PWM. Can you provide me with any help
I would be happy to help, but might need slightly more info about your motors and the weight of your bot. I have several designs for H-bridges that are smaller than the triple8, easier to build, and cheaper parts... but I would want to make sure I give you a design that works for your purpose.
~jd
It looks like those motors are ungeared (is that right?)... and if so, they will draw far more current than 5amps under full load. Especially if they are going into a combat robot (I gather from the fact that it will have a weapon system...). I would go with a 25 amp (minimum) motor-controller to be safe. I used a set of (4) 100w Currie scooter motors (ungeared and about the same size as yours) to drive a small battle-bot, using (4) 12amp Sabertooth motor-controllers, and they tripped the overcurrent protection with very little effort... ended up using a 25amp driver and they were fine.
You can use the Triple8 design as used on the Lawnbot, or I have another design if you care to see it.
~jd
Here is one of the motor-controllers I designed for my book:
https://sites.google.com/site/arduinorobotics/home/chapter8
It will handle upwards of 30amps and has an optional current sensor built in that you can read with the Arduino.
~jd
You can however, use Sealed Lead-Acid (SLA) batteries, like the ones used on an electric scooter.... something in the range of 12 Amp Hour to 33 AH would be sufficient.
Can I get the transmitter/receiver board diagram please.
Thanks,
Nolan
Sorry for the delay, I have been busy lately... When you say transmitter/receiver board... do you mean the Arduino breakout board with the headers for the receiver?
I never made Eagle files for the receiver board, since I only used that on my first design. The subsequent Arduino boards that I used were connected to the R/C receiver using female-to-female 3-wire Servo connectors. I moved away from plugging the receiver directly onto the board, as only certain receivers would fit in the space... if using a different receiver, it might not fit on the original board. Plus using Servo cables to connect the receiver made it easier to mount anywhere you like.
The only other circuit that I used (other than the Arduino and motor-controller) was the Failsafe circuit, which allowed the Arduino to control a high-power relay using a digital output pin... this disconnects the power going to the motor-controller using an extra channel on the Transmitter. For this you will need small n-channel mosfet to switch the relay (600mA to 1amp mosfet should suffice) and a high-power automotive power relay (40A, 12v from radio shack or auto-zone). You interface the Arduino to the N-channel mosfet and the mosfet controls the power relay.
Here is a png of that circuit:
https://sites.google.com/site/arduinorobotics/home/chapter10_
it is called "failsafe.png"
~jd
Could you please upload an eagle file (not just a .jpg image please) of both the h bridge diagram and the transmitter/receiver board diagram.
thank a lot
Nolan
Indeed... the files are here:
ftp://ftp.rediculouslygoodlooking.com/arduino/LawnBot400/Eagle%20files/triple-8/
with a bit more info on how to etch here:
http://www.rediculouslygoodlooking.com/site/triple-8.shtml
~jd
i also need the transmitter/receiver board diagram please.
Nolan
I always wanted a remote-control lawnmower.
I wanted study the video operation and noticed that it would be nice to see how you are operating the transmitter.
Have you modified the left stick(mode2)to be spring loaded to center?
I plan on using my old JR 9503 computer radio and playing with some of the mixing functions to ease the operational functions.
Keith
In far northeastern IL
As you may have gathered, I use the left (up/down) stick for the left motor and the right (up/down) stick for the right motor, which allows for easy tank-steering with no signal mixing in the code. This (for me) is the easiest method to control the lawnbot as it provides extremely precise control of each motor.
I later came up with some code to mix the X and Y axis signals from a single joystick, which makes it easier to drive in a straight line, but is not nearly as intuitive or controllable while turning... especially during zero-turns.
regards,
JD
I've got reverse disabled until a activate a toggle switch too. This is working on the breadboard, until I get the motor driver circuit done I won't know for sure.
I'm having difficulty etching the 2oz. copper and I had to stretch out the pcb layout for heatsinks, as they were too close.
PS - great instruct - I've got a dead mower in the back and I think I've found my winter project - thank you!
check it out here:
http://www.newegg.com/Product/Product.aspx?Item=N82E16826100006&nm_mc=OTC-Froogle&cm_mmc=OTC-Froogle-_-PC+Gaming+Accessories+%28Joystick+-+Game+Pad+-+etc.%29-_-OCZ+Technology-_-26100006