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[on:]

Hey everyone,

First post but I have been looking around for a week or so. I know how annoying it is when people ask questions that have already been asked on forums but I need to. I'm having a bit of trouble sorting through the information out there and am frankly new to the CNC DIY scene. I work on campus in a machine shop and we use CNC machines and I have axis to 3D printers and play with those occasionally. Recently a couple friends and I decided that it would be a good use of our free time to design a CNC machine to take to local high schools and do demonstrations. It would be a good way to introduce younger students to engineering using 3D modeling, CAM software, and then CNC machines. Students would have something to take home from their work too so it would likely help the info stick in their minds and keep them wondering about Purdue and perhaps the field of Technology as a career.

I do not have a lot of experience with the Arduino so the code will have to be provided as I can't code that well and neither can the other two. I know how to play with the Arduino just not to the extent of developing my own code for a machine of this caliber.

The design is not an issue. The three of us are decent 3D modelers and have professional programs that we get for being students and have designed several machines that we could produce. The electronics are hanging us up for now. There is no shortage of DIY CNC stepper controller boards, such as the linistepper. However there is a shortage of electronics setups that are USB driven or SD Card. The Arduino at least has the capability to drive a setup like this using something like the GRBL or the rStep but I am having trouble finding schematics for either. As I mentioned we have access to CNC machines and will likely cut our own boards or etch them ourselves and populate them with what we have laying around or can purchase from the EE building. But I need help figuring out what I actually need to know. If someone can point in the right direction I would appreciate it. I'll list what I feel is needed in the information department.

1. What type of software is used to run the setup. For instance the Linistepper uses Mach3 or Linux CNC. Does the GRBL or rStep use a simple GUI?
2. Is it possible to use a polou driver such as the one used in the Reprap design? Can the same setup be used and then drop the GRBL code into the arduino.
3. I have read that the GRBL is capable of driving a cnc machine using an UNO while the Reprap uses a Mega. Seeing as the UNO is cheaper that is ideal so could someone mention more info on this?
4. Are there any other bits of info that I need to know for this project?

If you are interested in joining our effort let me know, we are always looking for new ideas. If you want to do something similar for your school or want help with a design to donate to a school let me know and we can work something out. We are considering building them and selling them to schools for about cost (might wanna make something to help with the student loans )

[Reply #1 on:]

Where are you based?
I'm part way through building one myself
Cheers
Mike

[Reply #2 on:]

You can use arduino based controllers based on the RepRap project.
I made this project using a small arduino based circuit.
http://www.thebox.myzen.co.uk/Hardware/CNC_Conversion.html

Is it possible to use a polou driver such as the one used in the Reprap design?

Yes that is what my project did.

Are there any other bits of info that I need to know for this project?

Basically the controller, the thing that steps the motors uses Gcode. You need something to transfer that Gcode to your CNC.

[Reply #3 on:]

I'm also building a Arduino CNC.

You need something to transfer that Gcode to your CNC.

I'm writing a small software in Microsoft Visual Studio 2010 that should talk with my Arduino. If there is something that already does this, would be easier

[Reply #4 on:]

Where are you based?

Guessing by the username and words like 'campus', I'm guessing Indianapolis.

[Reply #5 on:]

I'm also building a Arduino CNC.

You need something to transfer that Gcode to your CNC.

I'm writing a small software in Microsoft Visual Studio 2010 that should talk with my Arduino. If there is something that already does this, would be easier

Well on my site is something I wrote in Processing so that will work on all platforms.

[Reply #6 on:]

Grumpy_Mike,

I stumbled across your design actually and liked it. I believe that it might work well. What did you use for the transfer of G-code, I don't remember seeing a USB interface. I am also on my phone so it is hard to navigate. Are those homemade Arduinos and a single pololu driver? I saw a circuit diagram so when I get home I'll exam it a bit more closely. I like the idea of the display and everything, looks nice and clean. I am a little worried about going outside my abilities at the beginning. I can follow a schematic well enough so could probably build it with a little help. Did it work well for you, the coil you machined looked quite good? What did you use to generate the G-code?

If I built the Reprap design would it allow me to use a version of software already developed? It is a fairly inexpensive design other than the mega. My main goal is attempt to use an Arduino UNO for the cost savings over the mega. Anything I use would be well documented for sharing. We will likely build a site to share everything and possible sell machined parts required for the build. If we sold machined parts it would allow those with few tools or access to precision machines to build at home.

As for location I am not in Indy. IUPUI is a satellite campus in Indy and I attend at the main campus in West Lafayette.

[Reply #7 on:]

Are those homemade Arduinos and a single pololu driver?

No there is three polou drivers and one arduino chip ( AT328 ) the other two chips are port expanders to get more I/O from the arduino.

What did you use to generate the G-code?

You can use inkscape, which is useful for engraving words.
But most of the stuff I either generated by hand straight into a text editor, or I wrote some helper applications in processing:-
http://www.thebox.myzen.co.uk/Mac_Apps/Processing.html

If I built the Reprap design would it allow me to use a version of software already developed?

Yes but then you would have to use a bigger ATmega chip than the 328