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Topic: How do I use an Arduino with a grblshield for a CNC machine? (Read 9335 times) previous topic - next topic

peterrichardjames

I am building a 3 axis cnc machine. I am using Nema 23 motors. I would like to move the machine using ad arduino and the grblshield. I have searched the net and haven't been able to find any tutorials or step by step guides as to how to go about this. I am quite new at using electronics and ardunio and it would be really useful to see images and walk-throughs of how to connect the motors to the grblshield (each nema motor has 8 wires) and then to see some arduino coding that I can use to turn the motors.
I know there are many smart people on this forum whom may have done something like this before and I would appreciate the help.
Thanks.

johnwasser

Have you studied the grblShield wiki?

https://www.synthetos.com/wiki/index.php?title=Projects:grblShield

It looks like grbl takes over the ATmega processor in your Arduino UNO and doesn't use the Arduino bootloader so it can't be uploaded as a sketch.  You will need AVR Studio 4 and a ISP programmer to load the grbl .hex file into your ATmega328P.
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peterrichardjames

Thank you for your reply.

So I won't be able to use Arduino 1.0 software to program the motors?

Where can I download AVR Studio 4 and a ISP programmer?

Arrch


AVR Studio 4

Google
Quote
and a ISP programmer?

I don't think they've invented a way to download hardware yet, although the 3-D printers are coming pretty close.

magagna

No you can't use the Arduino IDE to program the motors. You put GRBL on the Arduino, then send motor commands from your computer to the Arduino via the USB serial port. GRBL then takes care of turning your commands into stepper motor movements.

You can, however, install GRBL without AVR studio + a programmer. See this:

https://github.com/grbl/grbl/wiki/Flashing-Grbl-to-an-Arduino

Good luck!
http://en.wiktionary.org/wiki/magagna <-- My last name.  Pretty apt.

kf2qd


Have you studied the grblShield wiki?

https://www.synthetos.com/wiki/index.php?title=Projects:grblShield

It looks like grbl takes over the ATmega processor in your Arduino UNO and doesn't use the Arduino bootloader so it can't be uploaded as a sketch.  You will need AVR Studio 4 and a ISP programmer to load the grbl .hex file into your ATmega328P.


You won't need AVR Studio as all you already have access to the .HEX file. You will need another ATMega328P chip and to learn how to use the ArduinoISP sketch and program the new chip. You can then plug it into your Arduino Board  (provided you have the DIP type Arduino board) and then you can run grbl CNC.

peterrichardjames

Also how should I wire my nema23 motors into the grbl shield. I'm sure it is not as simple as just connecting them to the shield and slotting the shield onto the arduino. How should I wire up an extra power supply and resistors?

magagna

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Also how should I wire my nema23 motors into the grbl shield. I'm sure it is not as simple as just connecting them to the shield and slotting the shield onto the arduino. How should I wire up an extra power supply and resistors?


https://www.synthetos.com/wiki/index.php?title=Using_the_grblShield
http://en.wiktionary.org/wiki/magagna <-- My last name.  Pretty apt.

KD7BBJ

I know how you feel!  I'm in the same position.  I have all the parts to make a cnc machine and every time I ask for help all I get is a link to someplace that doesnt help

KD7BBJ

I need help interfacing my windows XP machine with th grbl shield and an UNOr3 with a grbl Chip.  I have all the parts to go but I dont know how to setup my computer.  Yes I have read all the grbl and wiki sheets and they dont help. 

I would like someone to say "plug this here, type this here, do this and that" so I can get this going.

thanks

vasquo


I need help interfacing my windows XP machine with th grbl shield and an UNOr3 with a grbl Chip.  I have all the parts to go but I dont know how to setup my computer.  Yes I have read all the grbl and wiki sheets and they dont help. 

I would like someone to say "plug this here, type this here, do this and that" so I can get this going.

thanks

I have a CNC machine. If you're DIYing your own, it's not a simple plug and play. You're in for a world of surprise if you think it's that easy as buying the parts and hooking them up together.

I bought a ready-made CNC with it's own motor controller, hooked up via LPT port to a Windows computer. Then I'm using Mach3 software to control the CNC machine.  The Gcode is generated by another software (forgot the name, EasyCAM or something like that), which takes a DXF version 12 file, which is created from/exported via AutoCAD software. 

I draw the plans in AutoCAD, export to DXF, import DXF into EasyCam, assign tools, depth, cuts to each path/layer, export Gcode, feed the Gcode into Mach3, click Start and off the CNC machine works.

I have no idea how you're going to do all that CNC using an Arduino and some shields only.

Once you have the CNC running, you're still not out of the woods. You'd then have to figure out the proper cutting speeds and depth for each material type you want to mill. Expect to break a lot of router bits (at a cost of $25 to $50 each) as you're experimenting. Then you need a bunch of miscellaneous stuff, fixtures, jigs, etc. 

Do you think this is easy?

Grumpy_Mike

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Yes I have read all the grbl and wiki sheets and they dont help. 

Why not what is it that you are not getting? We can't tell this, so ask specifically about just one bit you don't understand, then try and understand it. Then move onto the next bit. Don't try to do it all at once.

magagna


I need help interfacing my windows XP machine with th grbl shield and an UNOr3 with a grbl Chip.  I have all the parts to go but I dont know how to setup my computer.  Yes I have read all the grbl and wiki sheets and they dont help.  

I would like someone to say "plug this here, type this here, do this and that" so I can get this going.

thanks


GM and vasquo hit the nail on the head. We can definitely help you out with the pieces but ultimately it's probably going to be more complicated than you'd like or imagine.

GM's advice is very good; divide and conquer. Chop the problem up into smaller and smaller pieces until you can solve the little pieces, then start solving the little pieces, then start assembling them into more complicated tasks.

Vasquo's advice is also very good. I built a CNC machine last year and thought it would take a few weeks; it was more like 6 months before I knew what I was doing, and even now I'm still working on things like backlash and runout.

I'm not trying to discourage you from your project; I think they're incredibly useful machines and now can't imagine not having one, but I do think it's important to realize the road ahead is long. There is a huge difference between knowing how to drive a car and how to rebuild a carburetor; think of it like that.

Having said all that, back to your original issue. What do you need help with right now? Installing the drivers on your computer so it can see the Uno? Communicating with GRBL? Exporting something from CAD into G-Code?
http://en.wiktionary.org/wiki/magagna <-- My last name.  Pretty apt.

KD7BBJ

i had my motors stuttering once but i shut my machine down for the night and now its not working.  my first issue is that i cant get cool term to communicate with my pc

Grumpy_Mike

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my first issue is that i cant get cool term to communicate with my pc

Well that is hardly an arduino issue is it?
From what I can gather cool term is a program that runs on the PC not one that communicates with it. Is that right?

Why do you need this, will not the arduino's IDE terminal not work.
So how are you trying to get it to work?
I am assuming you must set it's baud rate to be the same as the arduino is sending, the one defined in the Serial.begin() call.
Are you doing that?
You must also set cool terms data format to 8 data 1 stop no parity.

Links to things would help.

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