How to easily build a 2-axis CNC plotter?

[Nick Johnson]

Suppose I want to build a very straightforward 2-axis CNC plotter in A3 form factor. The head would contain one or several pens, raised or lowered by solenoids (or whatever else ends up being appropriate). High poisitioning precision isn't a requirement Can anyone point me to some resources to get started investigating what would be involved?

-Nick

[tALSit de CoD]

You mean, like a small version of this one?

http://groups.google.com/group/sydney-hackspace/browse_thread/thread/22f5813e51e34f81/3d53df8b3d218035
// talsit.org

On 5 July 2011 12:13, Nick Johnson <arac...@notdot.net> wrote:

Suppose I want to build a very straightforward 2-axis CNC plotter in A3 form factor. The head would contain one or several pens, raised or lowered by solenoids (or whatever else ends up being appropriate). High poisitioning precision isn't a requirement Can anyone point me to some resources to get started investigating what would be involved?

-Nick

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[Glen Woolley]

Hack a day is a great source for inspiration. my advice is to copy the physical layout of other designs, there are only a handful of good 2axis CNC designs anyway

http://hackaday.com/?s=plotter

personally i like this one that uses a high powered laser instead of a pen[cil]

http://hackaday.com/2009/10/25/diy-plotter-with-laser/

On Tue, Jul 5, 2011 at 12:13 PM, Nick Johnson <arac...@notdot.net> wrote:

Suppose I want to build a very straightforward 2-axis CNC plotter in A3 form factor. The head would contain one or several pens, raised or lowered by solenoids (or whatever else ends up being appropriate). High poisitioning precision isn't a requirement Can anyone point me to some resources to get started investigating what would be involved?

-Nick

--

[Nick Johnson]

Not precisely - I want the gantry/head to move on 2 axis over a stationary surface, rather than moving the paper backwards and forwards.

-Nick

[Gav]

Definately use the eggbot hardware/software stack as a base. There's already plugins written to directly plot from inkscape:

http://egg-bot.com/

I'm working on a painting robot at the moment that uses it as a base.

[Nick Johnson]

On Tue, Jul 5, 2011 at 1:40 PM, Gav <the.mechat...@gmail.com> wrote:

Definately use the eggbot hardware/software stack as a base. There's already plugins written to directly plot from inkscape:

http://egg-bot.com/

I'm working on a painting robot at the moment that uses it as a base.

Hm, some of that seems like it could be useful, but I don't see how you'd use the hardware for something that requires linear, rather than rotational, motion. Can you elaborate?

[Gav]

The 'eibot' board is a stepper motor driver that interfaces to the PC. Should be fine for moderate size steppers. You design up the pattern in inkscape (in 2D), and it's plotted on the egg which introduces a distortion. Using a pair of linear axes will just draw the pattern directly, no distortion.

You can buy the board directly without getting an eggbot kit:

http://www.sparkfun.com/products/10025

The mechanical hardware is pretty straight forward but painful to make. Basically you want to have the rotary motion of the stepper converted into linear motion. You can either pick up readymade linear actuators off ebay (expensive, need to choose carefully) or make your own solution with belts and linear slides.

Here's a shot of a setup Shig and I made a few months ago to dodge up our own version of the 'kinect' before it came out. We used the eggbot controller as a base and an old plotter I had laying around as the mechanicals:

http://www.flickr.com/photos/55385315@N00/5183225059/in/photostream/

and the result:

http://www.flickr.com/photos/55385315@N00/5183242521/in/photostream/

[Nick Johnson]

On Tue, Jul 5, 2011 at 1:55 PM, Gav <the.mechat...@gmail.com> wrote:

The 'eibot' board is a stepper motor driver that interfaces to the PC. Should be fine for moderate size steppers. You design up the pattern in inkscape (in 2D), and it's plotted on the egg which introduces a distortion. Using a pair of linear axes will just draw the pattern directly, no distortion.

You can buy the board directly without getting an eggbot kit:

http://www.sparkfun.com/products/10025

Very nice. I'm wanting to drive it from a microcontroller, though, so USB control is out, but sparkfun have other stepper motor drivers too.

 

The mechanical hardware is pretty straight forward but painful to make. Basically you want to have the rotary motion of the stepper converted into linear motion. You can either pick up readymade linear actuators off ebay (expensive, need to choose carefully) or make your own solution with belts and linear slides.

Here's a shot of a setup Shig and I made a few months ago to dodge up our own version of the 'kinect' before it came out. We used the eggbot controller as a base and an old plotter I had laying around as the mechanicals:

http://www.flickr.com/photos/55385315@N00/5183225059/in/photostream/

and the result:

http://www.flickr.com/photos/55385315@N00/5183242521/in/photostream/

This is particularly interesting because you seem to have a vertical setup. My ideal setup would have the whole thing vertically mounted, with a piece of paper behind the setup, which the plotter draws on with a pen held by the head (multiple pens would be even better!)